Tagged: Keck Toggle Comment Threads | Keyboard Shortcuts

  • richardmitnick 2:52 pm on July 27, 2017 Permalink | Reply
    Tags: , , , , Keck, , SpARCS collaboration,   

    From Keck: “Scientists Get Best Measure of Star-Forming Material in Galaxy Clusters in Early Universe” 

    Keck Observatory

    Keck Observatory.
    Keck, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland

    Keck Observatory

    Previously covered from Uc Riverside, https://sciencesprings.wordpress.com/2017/07/20/from-uc-riverside-scientists-get-best-measure-of-star-forming-material-in-galaxy-clusters-in-early-universe/. But Keck deserves its own story.

    July 26, 2017

    Mari-Ela Chock, Communications Officer
    W. M. Keck Observatory
    mchock@keck.hawaii.edu
    (808) 554-0567

    The international Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) collaboration based at the University of California, Riverside has combined observations from several of the world’s most powerful telescopes, including W. M. Keck Observatory on Maunakea, Hawaii, to carry out one of the largest studies yet of molecular gas – the raw material which fuels star formation throughout the universe – in three of the most distant clusters of galaxies ever found, detected as they appeared when the universe was only four billion years old. Allison Noble, a postdoctoral researcher at the Massachusetts Institute of Technology, led this newest research from the SpARCS collaboration.

    SpARCS collaboration
    5
    To date, we have spectroscopically confirmed about a dozen z > 1 clusters. Above are three examples of rich clusters which SpARCS has discovered.

    Results were recently published in The Astrophysical Journal Letters.

    2
    The Tadpole Galaxy is a disrupted spiral galaxy showing streams of gas stripped by gravitational interaction with another galaxy. Molecular gas is the required ingredient to form stars in galaxies in the early universe. Credit: HUBBLE LEGACY ARCHIVE, ESA, NASA AND BILL SNYDER.

    Clusters are rare regions of the universe consisting of tight groups of hundreds of galaxies containing trillions of stars, as well as hot gas and mysterious dark matter.

    First, the research team used spectroscopic observations from the Very Large Telescope in Chile and Keck Observatory’s powerful Multi-Object Spectrograph for Infrared Exploration (MOSFIRE) to confirm nearly a dozen galaxies were star-forming members of the three massive clusters.

    ESO/VLT at Cerro Paranal, with an elevation of 2,635 metres (8,645 ft) above sea level

    Keck/MOSFIRE on Keck 1, Mauna Kea, Hawaii, USA

    “Keck Observatory’s MOSFIRE data were essential to proving conclusively that the 11 galaxies analyzed (two pairs) were indeed members of the three clusters and not foreground galaxies,” said Gillian Wilson, a professor of physics and astronomy at UC Riverside and the leader of the SpARCS collaboration.

    Next, the researchers took images through multiple filters from NASA’s Hubble Space Telescope, which revealed a surprising diversity in the galaxies’ appearance, with some galaxies having already formed large disks with spiral arms.

    NASA/ESA Hubble Telescope

    One of the telescopes the SpARCS scientists used is the extremely sensitive Atacama Large Millimeter Array (ALMA) telescope capable of directly detecting radio waves emitted from the molecular gas found in galaxies in the early universe.

    ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

    ALMA observations allowed the scientists to determine the amount of molecular gas in each galaxy, and provided the best measurement yet of how much fuel was available to form stars.

    The researchers compared the properties of galaxies in these clusters with the properties of “field galaxies” (galaxies found in more typical environments with fewer close neighbors). To their surprise, they discovered that cluster galaxies had higher amounts of molecular gas relative to the amount of stars in the galaxy compared to field galaxies. The finding puzzled the team because it has long been known that when a galaxy falls into a cluster, interactions with other cluster galaxies and hot gas accelerate the shut off of its star formation relative to that of a similar field galaxy (the process is known as environmental quenching).

    “This is definitely an intriguing result,” said Wilson. “If cluster galaxies have more fuel available to them, you might expect them to be forming more stars than field galaxies, and yet they are not.”

    Allison Noble, a SpARCS collaborator and this study’s leader, suggests several possible explanations: It is possible that something about being in the hot, harsh cluster environment surrounded by many neighboring galaxies perturbs the molecular gas in cluster galaxies such that a smaller fraction of that gas actively forms stars. Alternatively, it is possible that an environmental process, such as increased merging activity in cluster galaxies, results in the observed differences between the cluster and field galaxy populations.

    “While the current study does not answer the question of which physical process is primarily responsible for causing the higher amounts of molecular gas, it provides the most accurate measurement yet of how much molecular gas exists in galaxies in clusters in the early universe,” Wilson said.

    The SpARCS team has developed new techniques using infrared observations from NASA’s Spitzer Space Telescope to identify hundreds of previously undiscovered clusters of galaxies in the early universe.

    NASA/Spitzer Infrared Telescope

    In the future, they plan to study a larger sample of clusters. The team has recently been awarded additional time on ALMA, Keck Observatory, and the Hubble Space Telescope to continue investigating how the neighborhood in which a galaxy lives determines for how long it can form stars.

    The Keck Observatory data were obtained as the result of a collaboration amongst Wilson and fellow UC faculty members Michael Cooper (UC Irvine) and Saul Perlmutter (UC Berkeley).

    About MOSFIRE

    The Multi-Object Spectrograph for Infrared Exploration (MOSFIRE), gathers thousands of spectra from objects spanning a variety of distances, environments and physical conditions. What makes this large, vacuum-cryogenic instrument unique is its ability to select up to 46 individual objects in the field of view and then record the infrared spectrum of all 46 objects simultaneously. When a new field is selected, a robotic mechanism inside the vacuum chamber reconfigures the distribution of tiny slits in the focal plane in under six minutes. Eight years in the making with First Light in 2012, MOSFIRE’s early performance results range from the discovery of ultra-cool, nearby substellar mass objects, to the detection of oxygen in young galaxies only two billion years after the Big Bang. MOSFIRE was made possible by funding generously provided by the National Science Foundation and astronomy benefactors Gordon and Betty Moore. It is currently the most in-demand instrument at Keck Observatory.

    Other Authors

    Michael McDonald, Massachusetts Institute of Technology
    Adam Muzzin, York University, Canada
    Julie Nantais, Universidad Andres Bello, Chile
    Gregory Rudnick, University of Kansas
    Eelco van Kampen, European Southern Observatory, Germany
    Tracy Webb, McGill University, Canada
    Howard K.C. Yee, University of Toronto, Canada
    Kyle Boone, UC Berkeley
    Andrew DeGroot, UC Riverside
    Anna Delahaye, McGill University, Canada
    Ricardo Demarco, Universidad de Concepción, Chile
    Ryan Foltz, UC Riverside
    Brian Hayden, UC Berkeley/Lawrence Berkeley National Laboratory
    Chris Lidman, Australian Astronomical Observatory
    Ariadna Manilla-Robles, European Southern Observatory, Germany

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

     
  • richardmitnick 1:49 pm on July 18, 2016 Permalink | Reply
    Tags: , , , Keck,   

    From Keck: “More Than 100 Planets Confirmed in Single Trove” 

    Keck Observatory

    Keck Observatory.
    Keck, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland

    Keck Observatory

    MEDIA CONTACT

    Steve Jefferson
    W. M. Keck Observatory
    (808) 881-3827
    sjefferson@keck.hawaii.edu

    MEDIA CONTACT

    Ian Crossfield
    University of Arizona
    (949) 923-0578
    ianc@lpl.arizona.edu

    1
    An artist’s impression of Kepler-78b, an Earth-sized rocky exoplanet discovered by Roberto Sanchis-Ojeda (MIT) using Kepler Space Telescope data, and confirmed by University of Hawaii astronomer Andrew Howard using W. M. Keck Observatory atop Mauna Kea. Courtesy of UH-Manoa.

    An international team of astronomers have discovered and confirmed a treasure trove of new worlds. The researchers achieved this extraordinary discovery of exoplanets by combining NASA’s K2 mission data with follow-up observations by Earth-based telescopes including the W. M. Keck Observatory on Maunakea, the twin Gemini telescopes on Maunakea and in Chile, the Automated Planet Finder of the University of California Observatories and the Large Binocular Telescope operated by the University of Arizona. The team confirmed more than 100 planets, including the first planetary system comprising four planets potentially similar to Earth. The discoveries are published online in The Astrophysical Journal Supplement Series.

    NASA/Kepler Telescope
    NASA/Kepler Telescope

    Gemini/North telescope at Manua Kea, Hawaii, USA
    Gemini/North telescope at Manua Kea, Hawaii, USA

    Gemini South telescope
    Gemini South telescope, Cerro Tololo Inter-American Observatory (CTIO) campus near La Serena, Chile

     UCO Lick Automated Planet Finder telescope
    UCO Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

    Large Binocular Telescope,  Mount Graham,  Arizona, USA
    U Arizona Large Binocular Telescope, Mount Graham, Arizona, USA

    Ironically, the bounty was made possible when the Kepler space telescope’s pointing system broke.

    In its initial mission, Kepler surveyed a specific patch of sky in the northern hemisphere, measuring the frequency with which planets whose sizes and temperatures are similar to Earth occur around stars like our sun. But when it lost its ability to precisely stare at its original target area in 2013, engineers created a second life for the telescope that is proving remarkably fruitful.

    The new mission, dubbed K2, has provided the capability of observing a series of independent target fields in the ecliptic plane with greater opportunities for Earth-based observatories in both the northern and southern hemispheres. Additionally, in contrast to the Kepler mission, K2 is an entirely community-driven mission with all targets proposed for by the scientific community. K2 now looks at a larger fraction of cooler, smaller, red dwarf-type stars, which are much more common in our Milky Way than sun-like stars.

    “Kepler’s original mission observed a small patch of sky as it was designed to conduct a demographic survey of the different types of planets,” said Ian Crossfield, a Sagan Fellow at the University of Arizona’s Lunar and Planetary Laboratory, who led the research effort. “This approach effectively meant that relatively few of the brightest, closest red dwarfs were included in Kepler’s survey. The K2 mission allows us to increase the number of small, red stars by a factor of 20 for further study.”

    One of the most interesting set of planets discovered in this study is a system of four potentially rocky planets, between 20 and 50 percent larger than Earth, orbiting a star less than half the size and with less light output than the Sun. Their orbital periods range from five-and-a-half to 24 days, and two of them may experience radiation levels from their star comparable to those on Earth.

    Despite their tight orbits — closer than Mercury’s orbit around the sun — the possibility that life could arise on a planet around such a star cannot be ruled out, according to Crossfield.

    “Because these smaller stars are so common in the Milky Way, it could be that life occurs much more frequently on planets orbiting cool, red stars rather than planets around stars like our sun,” Crossfield said.

    To validate candidate planets identified by K2, the researchers obtained high-resolution images of the planet-hosting stars from Keck Observatory’s near infrared camera (NIRC2), the Gemini and Large Binocular Telescope (among others) as well as high-resolution optical spectroscopy using Keck Observatory’s high resolution spectrograph (HIRES) instrument and the AUtomated Planet Finder. By dispersing the starlight, the spectrographs allowed the researchers to measure the physical properties of a star — such as mass, radius and temperature — and infer the properties of any planets orbiting it.

    Keck NIRC2 Camera
    Keck NIRC2 Camera

    Keck HIRES
    Keck HIRES

    “Our analysis shows that by the end of the K2 mission, we expect to double or triple the number of relatively small planets orbiting nearby, bright stars,” Crossfield said. “And because these planets orbit brighter stars, we’ll be able to more easily study everything possible about them, whether it’s measuring their masses with Doppler spectroscopy — already underway at Keck Observatory and APF — or measuring their atmospheric makeup with the James Webb Space Telescope in just a few years.”

    For a full list of authors and funding information, please see the research paper, “197 Candidates and 104 Validated Planets in K2’s First Five Fields,” available for download at https://www.lpl.arizona.edu/~ianc/docs/crossfield….

    NIRC2 (the Near-Infrared Camera, second generation) works in combination with the Keck II adaptive optics system to obtain very sharp images at near-infrared wavelengths, achieving spatial resolutions comparable to or better than those achieved by the Hubble Space Telescope at optical wavelengths. NIRC2 is probably best known for helping to provide definitive proof of a central massive black hole at the center of our galaxy. Astronomers also use NIRC2 to map surface features of solar system bodies, detect planets orbiting other stars, and study detailed morphology of distant galaxies.

    HIRES (the High-Resolution Echelle Spectrometer) produces spectra of single objects at very high spectral resolution, yet covering a wide wavelength range. It does this by separating the light into many “stripes” of spectra stacked across a mosaic of three large CCD detectors. HIRES is famous for finding planets orbiting other stars. Astronomers also use HIRES to study distant galaxies and quasars, finding clues to the Big Bang. 


    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

    Keck NASA

    Keck Caltech

     
  • richardmitnick 7:33 am on May 5, 2016 Permalink | Reply
    Tags: , , Keck   

    From Keck: “Even in Deep Space, There Are Shades of Black” 

    WordPress is not working properly. I will do the best that I can.

    Keck Observatory

    Keck Observatory.
    Keck, with Subaru and IRTF (NASA Infrared Telescope Facility). Vadim Kurland

    Keck Observatory

    May 3, 2016
    BY FARISA Y. MORALES for Zocalo Public Square

    In my line of work, I stare at shades of black.

    My work starts on dark, black nights, when there is no moon or reflection from it. The telescopes I use have to be in places with three qualities: High, dry, and — you guessed it — very dark. And so, I search for planets atop the summit of the highest, driest, and darkest peak in Hawaii. Mauna Kea, a dormant volcano — where the world-famous W, M, Keck Observatory is located — minimizes the “noise” in the images from Earth’s constantly swirling atmosphere and the light drifting in from cities.

    Because black is defined by the absence of light, you might not think there are different gradations of black — but there are when you are hunting for other planets in our galaxy. Every day, I am looking through images that appear, at first, like exposures devoid of any light. In reality, shades of black can hide amazing worlds — some of which could be habitable or inhabited by life forms.

    Seeing the color black in fact is a comforting affirmation that I’m searching in the right direction, for a planet must be so faint as to appear to not be there at all. If an image has many bright dots of light, that means I am looking at a field full of stars. I am not interested in objects that emit their own light. A star is too extreme an environment for life as we know it — it’s an enormous ball of hot plasma and even if it had a solid surface to stand on, which it doesn’t, life forms like us would get crushed under the star’s tremendous gravitational pull.

    What I’m trying to find are very faint objects that reflect and re-emit the light from a host star nearby. These planets outside our solar system — which are known as exoplanets — are companions to stars, swimming in their own sea of darkness. Finding these planets tells us about the architecture of planetary systems. It also lets us know how common exoplanets are in the habitable regions around stars, where the temperatures are not too hot and not too cold, where liquid water can exist, and complex molecules may have figured out the processes we call life.


    Sample image of searching for a planet around a mature star, taken in March 2016 with the NIRC2 camera on Keck II telescope.

    My research uses the newest planet-hunting technique — “direct imaging.” Put simply, we place a small piece of black film in the field of view of the telescope to dampen the light from the parent star. Then, astronomers like myself can make out the faint planet companions orbiting the star. We rotate the powerful Keck telescope, taking pictures in a time-lapsed sequence, and then apply an intensive mathematical data analysis procedure. Through this process, we can carefully distinguish the feeble signal of a planet from the overwhelming glow of the host star. The dark piece of film is called a coronagraph, and it is a key component of the direct imaging technique.

    That’s right, I am actually trying to make the picture darker because the natural blackness of space is not enough to be able to see what we want to see. In order to extract the signal of a planet in an image, there is a lot of interference I have to take out: the random noise from the camera’s own electronics, the scattered light around the coronagraph, and the rotation of the individual exposures. The final image, a deeper tone of black, is the result of stacking cleaned-up exposures to reveal a clear signal from the planetary system. Galileo Galilei, the first observational astronomer, would be fascinated to see how we’ve progressed in the last 400 years. We are now seeing planets in the blackness around other stars, very much in the same way he discovered the faint moon companions around Jupiter.

    I did not set out to stare at blackness all day long. I came to astronomy by way of mathematics, which is a great tool for designing ways to see very small perturbations in data. But as I learned more about how astronomy could help expand the boundaries of human knowledge, I became more and more interested in trying to see what the universe conceals in the darkness.

    Ultimately, this is what all research is — seeking light in the darkness of the unknown. Our bodies are limited by the sensitivity of the human eye, but we have expanded our searches by manipulating the pixels of more sensitive cameras, and can thus capture evidence of real physical phenomena with our machines. If humans are to learn about how we came to be and search for life beyond ourselves, we must continue to look for answers in the deep blackness of space. And of course, we have to combine that with a little patience for staring into what may seem like a lot of nothingness.

    See the full article here. http://www.keckobservatory.org/recent/entry/even_in_deep_space_there_are_shades_of_black

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Mission
    To advance the frontiers of astronomy and share our discoveries with the world.

    The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth. The two, 10-meter optical/infrared telescopes on the summit of Mauna Kea on the Island of Hawaii feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrometer and world-leading laser guide star adaptive optics systems. Keck Observatory is a private 501(c) 3 non-profit organization and a scientific partnership of the California Institute of Technology, the University of California and NASA.

    Today Keck Observatory is supported by both public funding sources and private philanthropy. As a 501(c)3, the organization is managed by the California Association for Research in Astronomy (CARA), whose Board of Directors includes representatives from the California Institute of Technology and the University of California, with liaisons to the board from NASA and the Keck Foundation.
    Keck UCal

    Keck NASA

    Keck Caltech

     
c
Compose new post
j
Next post/Next comment
k
Previous post/Previous comment
r
Reply
e
Edit
o
Show/Hide comments
t
Go to top
l
Go to login
h
Show/Hide help
shift + esc
Cancel
%d bloggers like this: