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  • richardmitnick 11:02 am on June 2, 2022 Permalink | Reply
    Tags: "Small Molecules Have Big Impacts in Interstellar Clouds", , , Diffuse atomic gas becomes dense molecular gas which ultimately forms stars and stellar systems and continues to evolve over time., Hydrides are useful to astronomers because they are very sensitive tracers of different phases of the interstellar medium., NASA/DLR SOFIA, Scientists are studying six hydrides which are molecules or molecular ions in which one or more hydrogen atoms are bound to a heavier atom through shared electron pairs., , Though astronomers understand much of this process there are a lot of missing pieces., W3 is one of the 25 Milky Way regions scientists are studying in the HyGAL project.   

    From NASA/DLR SOFIA : “Small Molecules Have Big Impacts in Interstellar Clouds” 

    NASA SOFIA

    From NASA/DLR SOFIA

    May 31, 2022
    Anashe Bandari

    “One of the key goals, when you think about modern astronomy, considers the life cycle of molecular material,” said Arshia Jacob, an astronomer at Johns Hopkins University. Diffuse atomic gas becomes dense molecular gas, which ultimately forms stars and stellar systems, and continues to evolve over time. Though astronomers understand much of this process, there are a lot of missing pieces.

    Jacob is the lead author on a recent paper characterizing the interstellar medium in the Milky Way using SOFIA, the Stratospheric Observatory for Infrared Astronomy, to fill in some of these missing pieces [The Astrophysical Journal]. By studying six hydrides, which are molecules or molecular ions in which one or more hydrogen atoms are bound to a heavier atom through shared electron pairs, Jacob and her collaborators hope to better understand how molecular clouds form and evolve.

    1
    W3, one of the 25 Milky Way regions the HyGAL project will study, is seen as the glowing white area in the upper right of this image of the Heart and Soul Nebulae, taken by NASA’s Wide-field Infrared Survey Explorer (WISE).

    SOFIA looked at the abundances of six hydride molecules in W3, the spectra of two of which are shown in the box at left. Image credit: Nebulae: NASA/JPL-Caltech/UCLA; Spectra: Jacob et al.

    Hydrides are useful to astronomers because they are very sensitive tracers of different phases of the interstellar medium, and their chemistry is relatively straightforward. Moreover, hydride observations provide measurements of the amount of material present.

    The multi-investigator SOFIA project Hydrides in the Galaxy (HyGAL) uses a diverse selection of hydride molecules, allowing different processes to be monitored while complementing other observations. For example, one of the hydrides studied, argonium, can only form in regions that are almost purely atomic gas, so detecting argonium is indicative of a low molecular content in its surrounding environment. Other hydride molecules can indicate the presence of dense gas, intense cosmic radiation, turbulence, and more.

    “Hydrides are small, but we can understand so much from them. Small molecules, big impact,” Jacob said.

    In the first stage of the project, the group compared the hydride abundances in three regions of the Milky Way: two star-forming regions, W3(OH) and W3 IRS5, and a young stellar object, NGC 7538 IRS1. Though the average properties of these first three sources are similar, the full HyGAL project plans to study a total of 25 regions. With the remaining 22 sources covering distances from the inner galaxy all the way to the outer galaxy, they expect vastly different results.

    “The sources are very different: Some of them are older, some have more chemical enrichment, some are younger and still forming stars,” Jacob said. “All of these will affect the nature of molecules that are formed, like their abundances, for example.”

    Moving away from the galactic center, the transitions from atomic to molecular gas change, and the cosmic ray ionization rates vary vastly, which will result in differences in the ratios of molecules present and other properties. This will help astronomers understand the diversity of environments within the Milky Way.

    “Imagine you’re moving into a cloud. At each stage, you’re seeing different molecules, reflecting changes in the cloud properties as it gets denser,” Jacob said. “Through this project, we’re filling in the properties of this transition.”

    Currently, there have only been a handful of bright sources emitting a broad range of radiation that have been studied in this way, all concentrated in the inner galaxy. The SOFIA data will more than double the existing data, providing additional answers about the structure, dynamics, and chemistry of these clouds and where the dense material comes from.

    SOFIA is the only facility presently capable of accessing the frequency range necessary for these observations at the required resolution. The German REceiver Astronomy at Terahertz Frequencies (GREAT) instrument [below] aboard SOFIA allows five frequencies to be monitored simultaneously, each tuned to five of the six hydrides in question to determine the makeup of the cloud sources. These are complemented by studies at radio wavelengths with observatories such as the Karl G. Jansky Very Large Array near Socorro, New Mexico.

    “The idea is to give us not only information about the sources themselves, but also information about the different spiral arms they cross, making this truly a study over galactic scales,” Jacob said.

    See the full article here .

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    NASA/DLR SOFIA GREAT [German Receiver for Astronomy at Terahertz Frequencies]

    NASA/DLR SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera

    NASA/DLR SOFIA Forcast

    SOFIA is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Hangar 703, in Palmdale, California.

    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [NASA/ESA Hubble, NASA Chandra, NASA Spitzer, and associated programs.] NASA shares data with various national and international organizations such as from [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 5:37 pm on November 9, 2021 Permalink | Reply
    Tags: , Airborne Astronomy, , , , NASA/DLR SOFIA,   

    From NASA/DLR SOFIA : “Magnetic Chaos Hidden Within the Whirlpool Galaxy” 

    NASA SOFIA

    From NASA/DLR SOFIA

    11/09/2021
    Alejandro Borlaff
    Joan Schmelz

    The Astrophysical Journal

    Messier 51 Whirpool Galaxy Image via NASA/ESA S. Beckwith (STScI) the Hubble Heritage Team (STScI/AURA)

    Hidden deep inside their spiral structure, an invisible force is affecting the evolution of galaxies — magnetic fields. Strong enough to regulate star formation and even drive gas into a supermassive black hole, magnetic fields might be one of the most important factors influencing how spiral galaxies evolve. In theory, the field could be affecting the global kinematics of the gas, modifying the rotation curve, and the redistribution of dense clouds of gas as they condense into stars. As a consequence, the magnetic fields might indirectly be forcing stars to migrate radially in the galactic disk. To detect these effects, it is necessary to map the shape of the magnetic fields in the cold, dense molecular clouds. However, traditional observations of magnetic fields made with radio telescopes are only sensitive to the diffuse interstellar gas that surrounds these star-forming regions, far away from where these fundamental effects might be taking place.

    Thanks to SOFIA, scientists have finally been able to observe the morphology of the magnetic field inside the molecular gas of the grand design Whirlpool galaxy (Messier 51). The High-resolution Airborne Wideband Camera (HAWC+)(below) is able to map the magnetic fields deep in the cold, dark molecular clouds. The research team then compared these results with the magnetic field maps of the diffuse gas made with the Very Large Array in New Mexico and the Effelsberg radio telescope in Germany.

    National Radio Astronomy Observatory(US)Karl G Jansky Very Large Array located in central New Mexico on the Plains of San Agustin, between the towns of Magdalena and Datil, ~50 miles (80 km) west of Socorro. The VLA comprises twenty-eight 25-meter radio telescopes.

    Effelsberg Radio Telescope- a radio telescope in the Ahr Hills (part of the Eifel) in Bad Münstereifel(DE)

    The magnetic field lines in the inner region of the Whirlpool galaxy show a regular spiral structure, but field lines in the molecular clouds decouple from those of the diffuse gas in the outskirts — closer to the companion galaxy Messier 51b. The field structure obtained with the far-infrared observations shows a strong distortion and large differences in their orientation with respect to the structure obtained with the radio observations. This decoupling might be related to the gravitational interaction with Messier 51b, but strikingly, this effect is not found in the inter-arm region where the gas density is much lower and many fewer stars are forming.

    Earlier models of the global structure and evolution of spiral galaxies that ignored the effects of magnetic fields were based on the hypothesis that the diffuse and molecular gas shared a common magnetic structure. The most important result from this work is the proof that there is a new force contribution to be reckoned with — the kpc-scale magnetic field of the molecular clouds.

    The shape of spiral galaxies results from the pattern of bright H II surrounding newborn stars. The magnetic field lines are also spiral shaped, but intriguingly, astronomers are not yet sure how either of these structures — the morphological or the magnetic — are formed or how they are connected. The morphological spiral arms are possibly the result of density waves that move around the disk, compressing the gas, and creating new stars as they pass. At the same time, these density waves might also compress the magnetic field lines, aligning the turbulent fields that form inside the molecular clouds.

    The observed differences between both tracers of the magnetic field support the presence of small-scale magnetic dynamos. When combined with galactic rotation and shear forces, these dynamos would help to create the striking spiral patterns visible in the magnetic field structure of the Whirlpool galaxy. Moreover, the observed differences between the orientation of the pitch angle in the inter-arm and arm regions also support the presence of spiral density waves, which would be compressing the magnetic field lines as the morphological spiral arms move through the galaxy.

    See the full article here .

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    NASA/DLR SOFIA GREAT [German Receiver for Astronomy at Terahertz Frequencies]

    NASA/DLR SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera

    NASA/DLR SOFIA Forcast

    SOFIA is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Hangar 703, in Palmdale, California.

     
  • richardmitnick 11:47 am on July 17, 2021 Permalink | Reply
    Tags: , , , , , NASA/DLR SOFIA,   

    From University of Maryland Computer Mathematics and Natural Sciences (US): “First Clear View of a Boiling Cauldron Where Stars are Born” 

    From University of Maryland Computer Mathematics and Natural Sciences (US)

    June 23, 2021 [Just now in social media.]

    Media Relations Contact:
    Kimbra Cutlip
    301-405-9463
    kcutlip@umd.edu

    UMD-led team used NASA’s SOFIA telescope to capture high-resolution details of a star nursery in the Milky Way.

    University of Maryland researchers created the first high-resolution image of an expanding bubble of hot plasma and ionized gas where stars are born. Previous low-resolution images did not clearly show the bubble or reveal how it expanded into the surrounding gas.

    1
    The RCW 49 galactic nebula pictured above is one of the brightest star-forming regions in the Milky Way. By analyzing the movement of carbon atoms in an expanding bubble of gas surrounding the Westerlund 2 star cluster within RCW 49, a UMD-led team of researchers have created the clearest image to date of a stellar-wind driven bubble where stars are born. Image Credit: NASA/JPL-Caltec (US)/E.Churchwell (University of Wisconsin (US)).

    The researchers used data collected by the Stratospheric Observatory for Infrared Astronomy (SOFIA) telescope to analyze one of the brightest, most massive star-forming regions in the Milky Way galaxy. Their analysis showed that a single, expanding bubble of warm gas surrounds the Westerlund 2 star cluster and disproved earlier studies suggesting there may be two bubbles surrounding Westerlund 2. The researchers also identified the source of the bubble and the energy driving its expansion. Their results were published in The Astrophysical Journal on June 23, 2021.

    “When massive stars form, they blow off much stronger ejections of protons, electrons and atoms of heavy metal, compared to our sun,” said Maitraiyee Tiwari, a postdoctoral associate in the UMD Department of Astronomy and lead author of the study. “These ejections are called stellar winds, and extreme stellar winds are capable of blowing and shaping bubbles in the surrounding clouds of cold, dense gas. We observed just such a bubble centered around the brightest cluster of stars in this region of the galaxy, and we were able to measure its radius, mass and the speed at which it is expanding.”

    The surfaces of these expanding bubbles are made of a dense gas of ionized carbon, and they form a kind of outer shell around the bubbles. New stars are believed to form within these shells. But like soup in a boiling cauldron, the bubbles enclosing these star clusters overlap and intermingle with clouds of surrounding gas, making it hard to distinguish the surfaces of individual bubbles.

    Tiwari and her colleagues created a clearer picture of the bubble surrounding Westerlund 2 by measuring the radiation emitted from the cluster across the entire electromagnetic spectrum, from high-energy X-rays to low-energy radio waves. Previous studies, which only radio and submillimeter wavelength data, had produced low-resolution images and did not show the bubble. Among the most important measurements was a far-infrared wavelength emitted by a specific ion of carbon in the shell.

    “We can use spectroscopy to actually tell how fast this carbon is moving either towards or away from us,” said Ramsey Karim (M.S. ’19, astronomy), a Ph.D. student in astronomy at UMD and a co-author of the study. “This technique uses the Doppler effect, the same effect that causes a train’s horn to change pitch as it passes you. In our case, the color changes slightly depending on the velocity of the carbon ions.”

    By determining whether the carbon ions were moving toward or away from Earth and combining that information with measurements from the rest of the electromagnetic spectrum, Tiwari and Karim were able to create a 3D view of the expanding stellar-wind bubble surrounding Westerlund 2.

    In addition to finding a single, stellar wind-driven bubble around Westerlund 2, they found evidence of new stars forming in the shell region of this bubble. Their analysis also suggests that as the bubble expanded, it broke open on one side, releasing hot plasma and slowing expansion of the shell roughly a million years ago. But then, about 200,000 or 300,000 years ago, another bright star in Westerlund 2 evolved, and its energy re-invigorated the expansion of the Westerlund 2 shell.

    “We saw that the expansion of the bubble surrounding Westerlund 2 was reaccelerated by winds from another very massive star, and that started the process of expansion and star formation all over again,” Tiwari said. “This suggests stars will continue to be born in this shell for a long time, but as this process goes on, the new stars will become less and less massive.”

    Tiwari and her colleagues will now apply their method to other bright star clusters and warm gas bubbles to better understand these star-forming regions of the galaxy. The work is part of a multi-year NASA-supported program called FEEDBACK.

    See the full article here .

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    U Maryland Campus

    About University of Maryland Computer Mathematics and Natural Sciences (US)

    The thirst for new knowledge is a fundamental and defining characteristic of humankind. It is also at the heart of scientific endeavor and discovery. As we seek to understand our world, across a host of complexly interconnected phenomena and over scales of time and distance that were virtually inaccessible to us a generation ago, our discoveries shape that world. At the forefront of many of these discoveries is the College of Computer, Mathematical, and Natural Sciences (CMNS).

    CMNS is home to 12 major research institutes and centers and to 10 academic departments: astronomy, atmospheric and oceanic science, biology, cell biology and molecular genetics, chemistry and biochemistry, computer science, entomology, geology, mathematics, and physics.

    Our Faculty

    Our faculty are at the cutting edge over the full range of these disciplines. Our physicists fill in major gaps in our fundamental understanding of matter, participating in the recent Higgs boson discovery, and demonstrating the first-ever teleportation of information between atoms. Our astronomers probe the origin of the universe with one of the world’s premier radio observatories, and have just discovered water on the moon. Our computer scientists are developing the principles for guaranteed security and privacy in information systems.

    Our Research

    Driven by the pursuit of excellence, the University of Maryland has enjoyed a remarkable rise in accomplishment and reputation over the past two decades. By any measure, Maryland is now one of the nation’s preeminent public research universities and on a path to become one of the world’s best. To fulfill this promise, we must capitalize on our momentum, fully exploit our competitive advantages, and pursue ambitious goals with great discipline and entrepreneurial spirit. This promise is within reach. This strategic plan is our working agenda.

    The plan is comprehensive, bold, and action oriented. It sets forth a vision of the University as an institution unmatched in its capacity to attract talent, address the most important issues of our time, and produce the leaders of tomorrow. The plan will guide the investment of our human and material resources as we strengthen our undergraduate and graduate programs and expand research, outreach and partnerships, become a truly international center, and enhance our surrounding community.

    Our success will benefit Maryland in the near and long term, strengthen the State’s competitive capacity in a challenging and changing environment and enrich the economic, social and cultural life of the region. We will be a catalyst for progress, the State’s most valuable asset, and an indispensable contributor to the nation’s well-being. Achieving the goals of Transforming Maryland requires broad-based and sustained support from our extended community. We ask our stakeholders to join with us to make the University an institution of world-class quality with world-wide reach and unparalleled impact as it serves the people and the state of Maryland.

    Our researchers are also at the cusp of the new biology for the 21st century, with bioscience emerging as a key area in almost all CMNS disciplines. Entomologists are learning how climate change affects the behavior of insects, and earth science faculty are coupling physical and biosphere data to predict that change. Geochemists are discovering how our planet evolved to support life, and biologists and entomologists are discovering how evolutionary processes have operated in living organisms. Our biologists have learned how human generated sound affects aquatic organisms, and cell biologists and computer scientists use advanced genomics to study disease and host-pathogen interactions. Our mathematicians are modeling the spread of AIDS, while our astronomers are searching for habitable exoplanets.

    Our Education

    CMNS is also a national resource for educating and training the next generation of leaders. Many of our major programs are ranked among the top 10 of public research universities in the nation. CMNS offers every student a high-quality, innovative and cross-disciplinary educational experience that is also affordable. Strongly committed to making science and mathematics studies available to all, CMNS actively encourages and supports the recruitment and retention of women and minorities.

    Our Students

    Our students have the unique opportunity to work closely with first-class faculty in state-of-the-art labs both on and off campus, conducting real-world, high-impact research on some of the most exciting problems of modern science. 87% of our undergraduates conduct research and/or hold internships while earning their bachelor’s degree. CMNS degrees command respect around the world, and open doors to a wide variety of rewarding career options. Many students continue on to graduate school; others find challenging positions in high-tech industry or federal laboratories, and some join professions such as medicine, teaching, and law.

     
  • richardmitnick 11:57 am on April 14, 2021 Permalink | Reply
    Tags: "Stellar feedback and an airborne observatory; a team led by a WVU researcher determined a nebula to be much younger than previously believed", , , , , NASA/DLR SOFIA,   

    From West Virginia University (US): “Stellar feedback and an airborne observatory; a team led by a WVU researcher determined a nebula to be much younger than previously believed” 

    1

    From West Virginia University (US)

    April 09, 2021
    Holly Legleiter

    In the southern sky, situated about 4,300 light years from Earth, lies RCW 120, an enormous glowing cloud of gas and dust. This cloud, known as an emission nebula, is formed of ionized gases and emits light at various wavelengths. An international team led by West Virginia University researchers studied RCW 120 to analyze the effects of stellar feedback, the process by which stars inject energy back into their environment. Their observations showed that stellar winds cause the region to expand rapidly, which enabled them to constrain the age of the region. These findings indicate that RCW 120 must be less than 150,000 years old, which is very young for such a nebula.

    About seven light years from the center of RCW 120 lies the boundary of the cloud, where a plethora of stars are forming. How are all of these stars being formed? To answer that question, we need to dig deep into the origin of the nebula. RCW 120 has one young, massive star in its center, which generates powerful stellar winds. The stellar winds from this star are much like those from our own Sun, in that they throw material out from their surface into space. This stellar wind shocks and compresses the surrounding gas clouds. The energy that is being input into the nebula triggers the formation of new stars in the clouds, a process known as “positive feedback” because the presence of the massive central star has a positive effect on future star formation. The team, featuring WVU postdoctoral researcher Matteo Luisi, used NASA/DLR SOFIA [Stratospheric Observatory for Infrared Astronomy] (the Stratospheric Observatory for Infrared Astronomy) to study the interactions of massive stars with their environment.

    SOFIA is an airborne observatory consisting of an 8.8-foot (2.7-meter) telescope carried by a modified Boeing 747SP aircraft. SOFIA observes in the infrared regime of the electromagnetic spectrum, which is just beyond what humans can see. For observers on the ground, water vapor in the atmosphere blocks much of the light from space that infrared astronomers are interested in measuring. However, its cruising altitude of seven miles (13 km), puts SOFIA above most of the water vapor, allowing researchers to study star-forming regions in a way that would not be possible from the ground. Overnight, the in-flight observatory observes celestial magnetic fields, star-forming regions (like RCW 120), comets and nebulae. Thanks to the new upGREAT receiver that was installed in 2015, the airborne telescope can make more precise maps of large areas of the sky than ever before.

    The observations of RCW 120 are part of the SOFIA FEEDBACK survey, an international effort led by researchers Nicola Schneider at the University of Cologne [Universität zu Köln](DE) and Alexander Tielens at the University of Maryland (US), which makes use of upGREAT to observe a multitude of star-forming regions.

    2
    Multi-color Spitzer image of RCW 120, showing hot dust (in red), warm gas (in green) and emission from stars (in blue). The contours show the spectroscopic [CII] line of ionized carbon observed with SOFIA, which indicates rapid expansion of the region toward us (blue contours) and away from us (red contours). The yellow star gives the location of the central, massive star in RCW 120. Credit: Matteo Luisi/West Virginia University.

    National Aeronautics and Space Administration(US)/Spitzer Infrared Space Telescope(US) no longer in service. Launched in 2003 and retired on 30 January 2020.

    The research team opted to observe the spectroscopic [CII] line with SOFIA, which is emitted from diffuse ionized carbon in the star-forming region. “The [CII] line is probably the best tracer of feedback on small scales, and—unlike infrared images—it gives us velocity information, meaning we can measure how the gas moves. The fact that we can now observe [CII] easily across large regions in the sky with upGREAT makes SOFIA a really powerful instrument to explore stellar feedback in more detail than was possible previously,” says Matteo.

    Using their [CII] observations from SOFIA, the research team found that RCW 120 is expanding at 33,000 mph (15 km/s), which is incredibly fast for a nebula. From this expansion speed, the team was able to put an age limit on the cloud and found that RCW 120 is much younger than previously believed. With the age estimate, they were able to infer the time it took for the star formation at the boundary of the nebula to kick in after the central star had been formed. These findings suggest that positive feedback processes occur on very short timescales and point to the idea that these mechanisms could be responsible for the high star formation rates that occurred during the early stages of the universe.

    Looking forward, the team hopes to expand this type of analysis to the study of more star forming regions. Matteo says, “The other regions we are looking at with the FEEDBACK survey are in different stages of evolution, have different morphologies, and some have many high-mass stars in them, as opposed to only one in RCW 120. We can then use this information to determine what processes primarily drive triggered star formation and how feedback processes differ between various types of star-forming regions.”

    Collaborators on this project include researchers from West Virginia University, the Green Bank Observatory (US), the University of Cologne [Universität zu Köln](DE), the MPG Institute for Radio Astronomy [MPG Institut für Radioastronomie](DE), Aix-Marseille University [Aix-Marseille Université] (FR), Pennsylvania State University (US), the University of Maryland and Leiden University [Universiteit Leiden] (NL).

    Science paper:
    Stellar feedback and triggered star formation in the prototypical bubble RCW 120
    Science Advances

    See the full article here.

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  • richardmitnick 4:46 pm on January 14, 2021 Permalink | Reply
    Tags: "Magnetic 'Highway' Channels Materials out of Cigar Galaxy Messier 82", , , , , , NASA/DLR SOFIA, Starburst galaxy,   

    From Universities Space Research Association: “Magnetic ‘Highway’ Channels Materials out of Cigar Galaxy Messier 82” 

    usra-bloc

    From Universities Space Research Association

    January 14, 2021

    Suraiya Farukhi, Ph.D.
    Director, External Communications
    sfarukhi@usra.edu
    443-812-6945

    What’s fueling the massive ejection of gas and dust out of the Cigar galaxy, otherwise known at Messier 82?

    1
    Magnetic fields in Messier 82, or the Cigar galaxy, are shown as lines over a visible light and infrared composite image of the galaxy from the Hubble Space Telescope and the Spitzer Space Telescope.

    NASA/ESA Hubble Telescope.

    NASA/Spitzer Infrared telescope no longer in service. Launched in 2003 and retired on 30 January 2020. Credit: NASA.

    Stellar winds streaming from hot new stars form a galactic super wind that is blasting out plumes of hot gas (red) and a huge halo of smoky dust (yellow/orange) perpendicular to the narrow galaxy (white). Researchers used the Stratospheric Observatory for Infrared Astronomy magnetic field data and tools that have been used extensively to study the physics around the Sun to extrapolate the magnetic field’s strength 20,000 lights-years around the galaxy. They appear to extend indefinitely into intergalactic space, like the Sun’s solar wind, and may help explain how the gas and dust have traveled so far away from the galaxy. Credit: NASA, SOFIA, L. Proudfit; NASA, ESA, Hubble Heritage Team; NASA, JPL-Caltech, C. Engelbracht

    NASA/DLR SOFIA modified Boeing 747 aircraft.

    We know that thousands of stars bursting into existence are driving a powerful super-wind that’s blowing matter into intergalactic space. New research shows that magnetic fields are also contributing to the expulsion of material from Messier 82, a well-known example of a starburst galaxy with a distinctive, elongated shape.

    The findings from NASA’s Stratospheric Observatory for Infrared Astronomy, or SOFIA, help explain how dust and gas can move from inside galaxies into intergalactic space, offering clues to how galaxies formed. This material is enriched with elements like carbon and oxygen that support life and are the building blocks for future galaxies and stars. The research was presented at the meeting of the American Astronomical Society.

    SOFIA, a joint project of NASA and the German Aerospace Center, DLR, previously studied the direction of magnetic fields close to the core of Messier 82, as the Cigar galaxy is officially known. This time the team applied tools that have been used extensively to study the physics around the Sun, known as heliophysics, to understand the magnetic field’s strength surrounding the galaxy at a distance 10 times larger than before.

    “This is old physics for studying the Sun, but new for galaxies,” said Joan Schmelz, an associate director at the Universities Space Research Association based at NASA’s Ames Research Center in Silicon Valley, and co-author of the upcoming paper about this research. “It’s helping us understand how the space between stars and galaxies became so rich with matter for future cosmic generations.”

    Located 12 million light-years from Earth in the constellation Ursa Major, the Cigar galaxy is undergoing an exceptionally high rate of star formation called a starburst. The star formation is so intense that it creates a “super wind” that blows material out of the galaxy. As SOFIA previously found using the instrument called the High-Resolution Airborne Wideband Camera, the wind drags the magnetic field near the galaxy’s core so that it’s perpendicular to the plane of the galaxy across 2,000 light-years.

    NASA/DLR SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera.

    Researchers wanted to learn if the magnetic field lines would extend indefinitely into intergalactic space like the magnetic environment in the solar wind, or turn over to form structures similar coronal loops that are found in active regions of the Sun. They calculate that the galaxy’s magnetic fields extend out like the solar wind, allowing the material blown by the super wind to escape into intergalactic space.

    These extended magnetic fields may help explain how gas and dust spotted by space telescopes have traveled so far away from the galaxy. NASA’s Spitzer Space Telescope detected dusty material 20,000 lightyears beyond the galaxy, but it was unclear why it had spread so far away from the stars in both directions instead of in a cone-shaped jet.

    “The magnetic fields may be acting like a highway, creating lanes for galactic material to spread far and wide into intergalactic space,” said Jordan Guerra Aguilera, a postdoctoral researcher at Villanova University in Pennsylvania and co-author on the upcoming paper.

    With rare exceptions, the magnetic field in the solar corona cannot be measured directly. So, about 50 years ago, scientists developed methods to accurately extrapolate magnetic fields from the Sun’s surface into interplanetary space, known in heliophysics as the potential field extrapolation. Using SOFIA’s existing observations of central magnetic fields, the research team modified this method to estimate the magnetic field 25,000 light-years around the Cigar galaxy.

    “We can’t easily measure the magnetic fields at scales this large, but we can extrapolate it with these tools from heliophysics,” said Enrique Lopez-Rodriguez, a Universities Space Research Association scientist for SOFIA based at Ames and lead author on the study. “This new, interdisciplinary method gives us the larger perspective that we need to understand starburst galaxies.”

    SOFIA is a joint project of NASA and the German Aerospace Center [DLR]. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. The High-Resolution Airborne Wideband Camera instrument was developed and delivered to NASA by a multi-institution team led by NASA’s Jet Propulsion Laboratory.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    USRA is an independent, nonprofit research corporation where the combined efforts of in-house talent and university-based expertise merge to advance space science and technology.

    SIGNIFICANCE & PURPOSE

    USRA was founded in 1969, near the beginning of the Space Age, driven by the vision of two individuals, James Webb (NASA Administrator 1961-1968) and Frederick Seitz (National Academy of Sciences President 1962-1969). They recognized that the technical challenges of space would require an established research base to develop novel concepts and innovative technologies. Together, they worked to create USRA to satisfy not only the ongoing need for innovation in space, but also the need to involve society more broadly so the benefits of space activities would be realized.

     
  • richardmitnick 11:31 am on December 28, 2020 Permalink | Reply
    Tags: "Shaping a Spiral Galaxy", , , , NASA/DLR SOFIA, NGC 1068 also known as Messier 77 a spiral galaxy   

    From NASA/DLR SOFIA: “Shaping a Spiral Galaxy” 

    NASA SOFIA Banner

    NASA SOFIA
    From NASA/DLR SOFIA

    Dec. 28, 2020
    Editor: Yvette Smith

    1
    Credit: NASA/SOFIA; NASA/JPL-Caltech/Roma Tre Univ.

    Magnetic fields in NGC 1068, or Messier 77, are shown as streamlines over a visible light and X-ray composite image of the galaxy from the Hubble Space Telescope, NuSTAR or the Nuclear Spectroscopic Array, and the Sloan Digital Sky Survey.

    NASA/ESA Hubble Telescope.

    NASA/DTU/ASI NuSTAR X-ray telescope.

    SDSS Telescope at Apache Point Observatory, near Sunspot NM, USA, Altitude2,788 meters (9,147 ft).

    Apache Point Observatory, near Sunspot, New Mexico Altitude 2,788 meters (9,147 ft).

    The magnetic fields align along the entire length of the massive spiral arms — 24,000 light years across (0.8 kiloparsecs) — implying that the gravitational forces that created the galaxy’s shape are also compressing the its magnetic field. This supports the leading theory of how the spiral arms are forced into their iconic shape known as “density wave theory.” SOFIA, the Stratospheric Observatory for Infrared Astronomy, studied the galaxy using far-infrared light (89 microns) to reveal facets of its magnetic fields that previous observations using visible and radio telescopes could not detect.

    Learn more: How to Shape a Spiral Galaxy

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA SOFIA GREAT [German Receiver for Astronomy at Terahertz Frequencies]

    NASA SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera

    NASA/SOFIA Forcast

    SOFIA is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Hangar 703, in Palmdale, California.

     
  • richardmitnick 1:56 pm on November 29, 2020 Permalink | Reply
    Tags: "Galaxy Survives Black Hole’s Feast – For Now", , , , , NASA/DLR SOFIA, The galaxy CQ4479   

    From NASA/DLR SOFIA: “Galaxy Survives Black Hole’s Feast – For Now” 

    NASA SOFIA Banner

    NASA SOFIA
    From NASA/DLR SOFIA

    Nov. 27, 2020

    Felicia Chou
    NASA Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

    Alison Hawkes
    Ames Research Center, Silicon Valley, Calif.
    650-604-4789
    alison.hawkes@nasa.gov

    1
    Illustration of the galaxy called CQ4479. The extremely active black hole at the galaxy’s center is consuming material so fast that the material is glowing as it spins into the black hole’s center, forming a luminous quasar. Quasars create intense energy that was thought to halt all star birth and drive a lethal blow to a galaxy’s growth. But SOFIA found that the galaxy CQ4479 is surviving these monstrous forces, holding on to enough cold gas, shown around the edges in brown, to birth about 100 Sun-sized stars a year, shown in blue. The discovery is causing scientists to re-think their theories of galactic evolution.
    Credit: NASA/ Daniel Rutter.

    The hungriest of black holes are thought to gobble up so much surrounding material they put an end to the life of their host galaxy. This feasting process is so intense that it creates a highly energetic object called a quasar – one of the brightest objects in the universe – as the spinning matter is sucked into the black hole’s belly. Now, researchers have found a galaxy that is surviving the black hole’s ravenous forces by continuing to birth new stars – about 100 Sun-sized stars a year.

    The discovery from NASA’s telescope on an airplane, the Stratospheric Observatory for Infrared Astronomy, can help explain how massive galaxies came to be, even though the universe today is dominated by galaxies that no longer form stars. The results are published in The Astrophysical Journal.

    “This shows us that the growth of active black holes doesn’t stop star birth instantaneously, which goes against all the current scientific predictions,” said Allison Kirkpatrick, assistant professor at the University of Kansas in Lawrence Kansas and co-author on the study. “It’s causing us to re-think our theories on how galaxies evolve.”

    SOFIA, a joint project of NASA and the German Aerospace Center, DLR, studied an extremely distant galaxy, located more than 5.25 billion light years away called CQ4479. At its core is a special type of quasar that was recently discovered by Kirkpatrick called a “cold quasar.” In this kind of quasar, the active black hole is still feasting on material from its host galaxy, but the quasar’s intense energy has not ravaged all of the cold gas, so stars can keep forming and the galaxy lives on. This is the first time researchers have a detailed look at a cold quasar, directly measuring the black hole’s growth, star birth rate, and how much cold gas remains to fuel the galaxy.

    “We were surprised to see another oddball galaxy that defies current theories,” said Kevin Cooke, postdoctoral researcher at the University of Kansas in Lawrence, Kansas, and lead author of this study. “If this tandem growth continues both the black hole and the stars surrounding it would triple in mass before the galaxy reaches the end of its life.”

    As one of the brightest and most distant objects in the universe, quasars, or “quasi-stellar radio sources,” are notoriously difficult to observe because they often outshine everything around them. They form when an especially active black hole consumes huge amounts of material from its surrounding galaxy, creating strong gravitational forces. As more and more material spins faster and faster toward the center of the black hole, the material heats up and glows brightly. A quasar produces so much energy that it often outshines everything around it, blinding attempts to observe its host galaxy. Current theories predict that this energy heats up or expels the cold gas needed to create stars, stopping star birth and driving a lethal blow to a galaxy’s growth. But SOFIA reveals there is a relatively short period when the galaxy’s star birth can continue while the black hole’s feast goes on powering the quasar’s powerful forces.

    Rather than directly observing the newborn stars, SOFIA used its 9-foot telescope to detect the infrared light radiating from the dust heated by the process of star formation. Using data collected by SOFIA’s High-resolution Airborne Wideband Camera-Plus, or HAWC+ instrument, scientists were able to estimate the amount of star formation over the past 100 million years.

    “SOFIA lets us see into this brief window of time where the two processes can co-exist,” said Cooke. “It’s the only telescope capable of studying star birth in this galaxy without being overwhelmed by the intensely luminous quasar.”

    The short window of joint black hole and star growth represents an early phase in the death of a galaxy, wherein the galaxy has not yet succumbed to the devastating effects of the quasar. Continued research with SOFIA is needed to learn if many other galaxies go through a similar stage with joint black hole and star growth before ultimately reaching the end of life. Future observations with the James Webb Space Telescope, which is scheduled to launch in 2021, could uncover how quasars affect the overall shape of their host galaxies.

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    SOFIA is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Hangar 703, in Palmdale, California.

    NASA SOFIA GREAT [German Receiver for Astronomy at Terahertz Frequencies]

    NASA SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera

    NASA/SOFIA Forcast

     
  • richardmitnick 12:05 pm on October 27, 2020 Permalink | Reply
    Tags: "NASA’s SOFIA Discovers Water on Sunlit Surface of Moon", , NASA/DLR SOFIA   

    From NASA/DLR SOFIA: “NASA’s SOFIA Discovers Water on Sunlit Surface of Moon” 

    NASA SOFIA Banner

    NASA SOFIA

    From NASA/DLR SOFIA

    Oct. 26, 2020

    Felicia Chou
    Headquarters, Washington
    202-358-0257
    felicia.chou@nasa.gov

    Alison Hawkes
    Ames Research Center, Silicon Valley, Calif.
    650-604-4789
    alison.hawkes@nasa.gov

    1
    This illustration highlights the Moon’s Clavius Crater with an illustration depicting water trapped in the lunar soil there, along with an image of NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) that found sunlit lunar water.
    Credits: NASA/Daniel Rutter.

    NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) has confirmed, for the first time, water on the sunlit surface of the Moon. This discovery indicates that water may be distributed across the lunar surface, and not limited to cold, shadowed places.

    SOFIA has detected water molecules (H2O) in Clavius Crater, one of the largest craters visible from Earth, located in the Moon’s southern hemisphere. Previous observations of the Moon’s surface detected some form of hydrogen, but were unable to distinguish between water and its close chemical relative, hydroxyl (OH). Data from this location reveal water in concentrations of 100 to 412 parts per million – roughly equivalent to a 12-ounce bottle of water – trapped in a cubic meter of soil spread across the lunar surface. The results are published in the latest issue of Nature Astronomy.

    “We had indications that H2O – the familiar water we know – might be present on the sunlit side of the Moon,” said Paul Hertz, director of the Astrophysics Division in the Science Mission Directorate at NASA Headquarters in Washington. “Now we know it is there. This discovery challenges our understanding of the lunar surface and raises intriguing questions about resources relevant for deep space exploration.”

    As a comparison, the Sahara desert has 100 times the amount of water than what SOFIA detected in the lunar soil. Despite the small amounts, the discovery raises new questions about how water is created and how it persists on the harsh, airless lunar surface.

    Water is a precious resource in deep space and a key ingredient of life as we know it. Whether the water SOFIA found is easily accessible for use as a resource remains to be determined. Under NASA’s Artemis program, the agency is eager to learn all it can about the presence of water on the Moon in advance of sending the first woman and next man to the lunar surface in 2024 and establishing a sustainable human presence there by the end of the decade.

    SOFIA’s results build on years of previous research examining the presence of water on the Moon. When the Apollo astronauts first returned from the Moon in 1969, it was thought to be completely dry. Orbital and impactor missions over the past 20 years, such as NASA’s Lunar Crater Observation and Sensing Satellite, confirmed ice in permanently shadowed craters around the Moon’s poles.

    NASA/ LCROSS

    Meanwhile, several spacecraft – including the Cassini mission and Deep Impact comet mission, as well as the Indian Space Research Organization’s Chandrayaan-1 mission – and NASA’s ground-based Infrared Telescope Facility, looked broadly across the lunar surface and found evidence of hydration in sunnier regions.

    NASA/ESA/ASI Cassini-Huygens Spacecraft.

    NASA Deep Impact spacecraft.

    ISRO Chandrayaan 2.

    NASA Infrared Telescope facility Mauna Kea, Hawaii, USA, 4,207 m (13,802 ft) above sea level.

    Yet those missions were unable to definitively distinguish the form in which it was present – either H2O or OH.

    “Prior to the SOFIA observations, we knew there was some kind of hydration,” said Casey Honniball, the lead author who published the results from her graduate thesis work at the University of Hawaii at Mānoa in Honolulu. “But we didn’t know how much, if any, was actually water molecules – like we drink every day – or something more like drain cleaner.”


    SOFIA Discovers Water on a Sunlit Surface of the Moon
    Scientists using NASA’s telescope on an airplane, the Stratospheric Observatory for Infrared Astronomy, discovered water on a sunlit surface of the Moon for the first time. SOFIA is a modified Boeing 747SP aircraft that allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Molecular water, H2O, was found in Clavius Crater, one of the largest craters visible from Earth in the Moon’s southern hemisphere. This discovery indicates that water may be distributed across the lunar surface, and not limited to cold, shadowed places.
    Credits: NASA/Ames Research Center.

    SOFIA offered a new means of looking at the Moon. Flying at altitudes of up to 45,000 feet, this modified Boeing 747SP jetliner with a 106-inch diameter telescope reaches above 99% of the water vapor in Earth’s atmosphere to get a clearer view of the infrared universe. Using its Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST), SOFIA was able to pick up the specific wavelength unique to water molecules, at 6.1 microns, and discovered a relatively surprising concentration in sunny Clavius Crater.

    “Without a thick atmosphere, water on the sunlit lunar surface should just be lost to space,” said Honniball, who is now a postdoctoral fellow at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Yet somehow we’re seeing it. Something is generating the water, and something must be trapping it there.”

    Several forces could be at play in the delivery or creation of this water. Micrometeorites raining down on the lunar surface, carrying small amounts of water, could deposit the water on the lunar surface upon impact. Another possibility is there could be a two-step process whereby the Sun’s solar wind delivers hydrogen to the lunar surface and causes a chemical reaction with oxygen-bearing minerals in the soil to create hydroxyl. Meanwhile, radiation from the bombardment of micrometeorites could be transforming that hydroxyl into water.

    How the water then gets stored – making it possible to accumulate – also raises some intriguing questions. The water could be trapped into tiny beadlike structures in the soil that form out of the high heat created by micrometeorite impacts. Another possibility is that the water could be hidden between grains of lunar soil and sheltered from the sunlight – potentially making it a bit more accessible than water trapped in beadlike structures.

    For a mission designed to look at distant, dim objects such as black holes, star clusters, and galaxies, SOFIA’s spotlight on Earth’s nearest and brightest neighbor was a departure from business as usual. The telescope operators typically use a guide camera to track stars, keeping the telescope locked steadily on its observing target. But the Moon is so close and bright that it fills the guide camera’s entire field of view. With no stars visible, it was unclear if the telescope could reliably track the Moon. To determine this, in August 2018, the operators decided to try a test observation.

    “It was, in fact, the first time SOFIA has looked at the Moon, and we weren’t even completely sure if we would get reliable data, but questions about the Moon’s water compelled us to try,” said Naseem Rangwala, SOFIA’s project scientist at NASA’s Ames Research Center in California’s Silicon Valley. “It’s incredible that this discovery came out of what was essentially a test, and now that we know we can do this, we’re planning more flights to do more observations.”

    SOFIA’s follow-up flights will look for water in additional sunlit locations and during different lunar phases to learn more about how the water is produced, stored, and moved across the Moon. The data will add to the work of future Moon missions, such as NASA’s Volatiles Investigating Polar Exploration Rover (VIPER), to create the first water resource maps of the Moon for future human space exploration.

    In the same issue of Nature Astronomy, scientists have published a paper using theoretical models and NASA’s Lunar Reconnaissance Orbiter data, pointing out that water could be trapped in small shadows, where temperatures stay below freezing, across more of the Moon than currently expected. The results can be found here.

    “Water is a valuable resource, for both scientific purposes and for use by our explorers,” said Jacob Bleacher, chief exploration scientist for NASA’s Human Exploration and Operations Mission Directorate. “If we can use the resources at the Moon, then we can carry less water and more equipment to help enable new scientific discoveries.”

    B-roll footage related to this finding is available at:

    https://go.nasa.gov/2TnDWSd

    Participate in a Reddit Ask Me Anything on our Moon exploration activities at 1 p.m. EDT Tuesday, Oct. 27:

    http://reddit.com/r/space

    Learn more about SOFIA at:

    https://www.nasa.gov/sofia

    NASA SOFIA GREAT [German Receiver for Astronomy at Terahertz Frequencies]

    NASA SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera

    NASA/SOFIA Forcast

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition
    SOFIA is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Hangar 703, in Palmdale, California.

    DLR Bloc

     
  • richardmitnick 11:38 am on June 4, 2020 Permalink | Reply
    Tags: "Magnetism Rules in the Milky Way’s Core", , , , , , NASA/DLR SOFIA,   

    From Sky & Telescope: “Magnetism Rules in the Milky Way’s Core” 

    SKY&Telescope bloc

    From Sky & Telescope

    June 4, 2020
    Govert Schilling

    1
    A composite image of the central region of our Milky Way galaxy, known as Sagittarius A. SOFIA found that magnetic fields, shown as streamlines, are strong enough to control the material moving around the black hole, even in the presence of enormous gravitational forces.
    NASA / SOFIA / L. Proudfit / ESA / Herschel / Hubble Space Telescope

    What governs the dynamics of gas close to the center of our Milky Way galaxy? Gravity is the standard answer. After all, there’s a 4 million-solar-mass black hole hiding there.

    But new data from NASA’s Stratospheric Observatory for Infrared Astronomy (SOFIA) reveal that strong magnetic fields may actually dominate, just like they do in the Sun’s corona. The new result may shed light on two outstanding questions about the galactic center.

    NASA/DLR SOFIA

    Into the Galactic Center

    SOFIA is a Boeing 747SP turned high-flying observatory. Its instrument, HAWC+, a far-infrared imaging polarimeter, studied the galactic center during flights in May 2017 and July 2018.

    NASA SOFIA High-resolution Airborne Wideband Camera-Plus HAWC+ Camera

    Measurements of the far-infrared light’s polarization revealed the orientation of dust particles, which rotate to align perpendicular to magnetic field lines.

    Charles Dowell (NASA / JPL) led a team in studying the central 15 light-years of the galactic center, deducing an average magnetic field strength of 0.005 gauss. That’s about 100 times weaker than the average magnetic field strength on Earth’s surface. But since the density in the galactic center is so low, only some 10,000 atoms per cubic centimeter, the gas’s magnetic pressure is much higher than its thermal pressure.

    As a result, gravity may not be the dominant force that determines the motions of the gas. Instead, “the magnetic field may govern the kinematics and channel the plasma, just like magnetic fields dominate the physics of the solar corona,” says team member Joan Schmelz (Universities Space Research Association), who presented the preliminary results Tuesday at the virtual meeting of the American Astronomical Society.

    “The data provide the most detailed look yet at the magnetic fields surrounding our galaxy’s central black hole,” says team member David Chuss (Villanova University).

    Explaining Strange Black Hole Behavior

    Andrew Fox (Space Telescope Science Institute), who was not involved in the study, says the results are not really surprising. “The galactic center is a very energetic region full of highly ionized plasmas,” he says, “so it makes sense that magnetic fields would dominate other sources of pressure.”

    But according to Schmelz, astrophysicists generally tend to avoid including the effects of magnetic fields because they complicate the picture. “We’re now confronted with data that are so compelling that we just can’t ignore magnetic fields anymore,” she says.

    If magnetic fields govern gas motions rather than just gravity, this may explain two surprising facts about the core of our Milky Way galaxy: the low birth rate of new stars (despite the presence of huge amounts of gas) and the weak activity of the galaxy’s central black hole. Strong magnetic fields could both suppress star formation and prevent matter from falling into the black hole.

    Meanwhile, Schmelz cautions that calculating magnetic field strength from polarization data is not straightforward. “Our next step is to check if our standard techniques do apply in this turbulent environment,” she says. “So far, the observation of Zeeman effects in the Milky Way center [the splitting of spectral lines in the presence of strong magnetic fields] compares favorably with our results.”

    See the full article here .

    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope magazine, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

     
  • richardmitnick 11:39 am on April 16, 2020 Permalink | Reply
    Tags: , , , , , , NASA/DLR SOFIA, Texas Echelon-Cross-Echelle Spectrograph   

    From AAS NOVA: “Observations of Betelgeuse’s Dimming from the Stratosphere” 

    AASNOVA

    From AAS NOVA

    1
    Artist’s impression of the roiling surface and strong stellar winds of Betelgeuse, a red supergiant star. [ESO/L. Calçada]

    2
    This plot of V-band brightness shows Betelgeuse’s regular ~420-day pulsations, as well as the unprecedented dip in recent months. Red filled circles show the times of the three SOFIA/EXES observations compared in this study. [Harper et al. 2020]

    The unprecedented dimming of the red supergiant star Betelgeuse has been making headlines since late last year. To find out what’s causing it, an airplane-borne telescope took to the skies.

    A Dramatic Decline

    In October 2019, Betelgeuse — identifiable as the bright, massive red supergiant lying at the left shoulder of the constellation Orion — began declining in brightness. By February 2020, it had dimmed to less than 40% of its average luminosity, leading some to speculate that this star might be preparing to end its life as a dramatic supernova.

    But Betelgeuse doesn’t appear to be going anywhere just yet. In February 2020, the star stopped dimming and started to climb in brightness again — and yet we still don’t know what caused its remarkable drop.

    3
    Betelgeuse, shown here in an infrared image from the Herschel Space Observatory, is a luminous red supergiant star located about 700 light-years away. [ESA/Herschel/PACS/L. Decin et al.]

    The Role of Red Supergiants

    Why do we want to understand what’s happening with Betelgeuse? Red supergiants like this one represent a late evolutionary stage of massive stars. In this phase, strong winds flow off of the star, carrying away mass and populating the surrounding area with enriched stellar material.

    But despite the important role these stars play in shaping galaxies and populating them with elements, the red supergiant stage is poorly understood, and there’s a lot we don’t know about the atmosphere, outflows, and timing of a star’s behavior during this phase. By tracking the evolution of Betelgeuse, a conveniently bright and nearby laboratory, we can further explore these processes.

    A Telescope in Flight

    Scientists have proposed two main explanations for Betelgeuse’s recent dimming: either it’s an intrinsic cooling of the star’s photosphere, or Betelgeuse has thrown off dust that’s now lying between it and us, blocking some of its light.

    4
    NASA/DLR SOFIA carrying a 2.7-m telescope.

    Because infrared observations will be critical to exploring these options, NASA-DLR’s Stratospheric Observatory for Infrared Astronomy (SOFIA) planned an extensive campaign to look at Betelgeuse and its environment.

    SOFIA consists a telescope mounted on an airplane that flies above 99% of the Earth’s infrared-blocking atmosphere. Observations of Betelgeuse were planned throughout winter/spring 2020 with all the instruments scheduled to fly on SOFIA. Now the first of these results, from the Echelon Cross-Echelle Spectrograph (EXES) instrument, have been published in a new study led by Graham Harper (University of Colorado Boulder).

    Texas Echelon-Cross-Echelle Spectrograph

    Going with the Flow

    Harper and collaborators explored Betelgeuse’s circumstellar envelope, the sphere of stellar material that flows off of and surrounds the star. In particular, the SOFIA/EXES observations are of two gas emission lines: singly ionized iron, and neutral sulfur. The authors compare observations of these lines from February 2020, when Betelgeuse was at its dimmest, to observations from 2015 and 2017, when Betelgeuse was at its normal brightness.

    5
    SOFIA/EXES observations of the ionized iron emission line around Betelgeuse during Cycle 2 (2015; yellow), Cycle 5 (2017; red) and Cycle 7 (February 2020; blue). [Harper et al. 2020]

    The team finds that the lines from the different observing cycles are very nearly the same, suggesting that Betelgeuse’s circumstellar flow has not been affected by whatever caused the star to dim — whether that’s changes in the photosphere or the presence of new dust in the sightline to the star. The observations also indicate that the heating from the stellar wind didn’t change during the dimming.

    These results are one more piece in the puzzle of Betelgeuse’s strange behavior. And with additional observations from other SOFIA instruments soon to be analyzed, we can anticipate more news to come!

    Citation

    “SOFIA-EXES Observations of Betelgeuse during the Great Dimming of 2019/2020,” Graham M. Harper et al 2020 ApJL 893 L23.
    https://iopscience.iop.org/article/10.3847/2041-8213/ab84e6

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
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