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  • richardmitnick 9:34 am on May 13, 2017 Permalink | Reply
    Tags: , , , , , HL Tauri (also called HL Tau), NAOJ   

    From ALMA: “Universe Observed through Visual Acuity of 120,000/20 [vol.1] Astronomers Stunned by HL Tauri” 

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

    2017.05.09
    Interviewed and written by Toshihiro Nakamura
    Photographed by: Nozomu Toyoshima

    In 2014, astronomers were stunned by the ultra-high resolution image of HL Tauri (also called HL Tau) observed by ALMA, revealing a key element to unveil the formation process of a planetary system. What is so extraordinary about HL Tau that looks like a record floating in the night sky? For the answer, we interviewed with Professor Tetsuo Hasegawa at the NAOJ Chile Observatory.

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    First Impression was “Moved and Relieved”

    — That image taken in 2014 was widely featured by international media as a remarkable achievement of ALMA, and it also arouse much controversy among astronomers. What was your first impression when you saw the image?

    Hasegawa: This image shows a planet forming disk around a young star called HL Tau, clearly revealing narrow concentric rings separated by gaps. It was much more detailed and more beautiful than we expected. I was moved and relieved at the same time.

    — Relieved? What kind of feeling was it?

    Hasegawa: To make our budget request for ALMA, we explained our simulation to the government agency saying that ALMA is capable of taking more accurate astronomical images that have never been possible with existing radio telescopes, and also telling that ALMA will make great contributions to science. I was certain that ALMA would make it, but when I saw it in reality, honestly I was relieved (laugh).

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    Proposal Documents of ALMA Project Credit:Geoff Bryden et al. (2000) ApJ, all rights reserved.

    A Record-like Disk Reveals Formation of the Solar System

    — To begin with, what is the star HL Tau like?

    Hasegawa: It’s a young star approximately 450 light years from the Earth, merely a million years old.

    — Our solar system is about 4.6 billion years old, right?

    Hasegawa: Correct. In analogy, if we compare our 4.6 billion-year-old Sun to a 46-year-old man, HL Tau would be 0.01 years old, in other words only 4 days after birth.

    — It’s like a baby star, rather than young. Does this whole orange disk consists of a baby star?

    Hasegawa: No, the star is located at the center of this record-like disk. It is surrounded by gas and dust, which will grow into planets that orbit HL Tau. This clump of gas and dust is called “a protoplanetary disk”.

    — Are planets formed in gas and dust?

    Hasegawa: Right. Sun-like stars and planets like the Earth and Jupiter were formed in gas and dust floating in space. So, this image shows the very early stage of planet formation around a baby star.

    — Did our solar system used to have a similar shape?

    Hasegawa: If we could travel back to 4.6 billion years ago and see our solar system at the age of a million years, we would see a similar object like this.

    ALMA Makes Blurry Image Incredibly Clear

    — Is this the first image of a planet forming disk?

    Hasegawa: The first reception of radio signals from a protoplanetary disk was made by the Nobeyama 45-m Telescope in 1993.

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    Nobeyama 45-m Telescope. http://www.nao.ac.jp/en/project/nro.html

    And then later on, the(NMA) captured this first image of a protoplanetary disk.

    Nobeyama Millimeter Array [NMA], located near Minamimaki, Nagano at an elevation of 1350m

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    Radio spectrum from a gas disk Credit:Skrutskie et al. 1993 ApJ 409, 422, reproduced by permission of the AAS, all rights reserved.

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    Radio spectrum from a gas disk around GG Tau Credit:Kawabe et al. 1993, ApJ 404, 63, reproduced by permission of the AAS, all rights reserved.

    — It doesn’t look like an astronomical object at all.

    Hasegawa: A radio telescope has poor eyesight when compared with an optical telescope. In astronomical terms, we say, “low resolution”. The eyesight of a telescope increases in proportion to the aperture size, which means the eyesight improves with a larger size of lens or mirror for an optical telescope and with a larger size of antenna for a radio telescope. But, when we compare the eyesight between an optical and a radio telescope with the same size of aperture, the vision of a radio telescope is equivalent to only 1/10,000 of an optical telescope. Since the maximum extension of the NMA is up to 130 meters, it is only capable to take this level of blurred image. After this, various observations have been made and this is an image of HL Tau captured in 2002 by the NMA with higher resolution.

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    HL Tau observed with NMA Credit:Kitamura et al. 2002, ApJ, 581, 357, reproduced by permission of the AAS, all rights reserved.

    — Let’s see…hmm, this is just a line, isn’t it? It’s hard to believe this is the same object observed by ALMA this time.

    Hasegawa: I agree with you. We can hardly imagine how planets will be formed from this image.

    — But, by extending 66 antennas up to 16 km and combining received signals, we can make a virtual giant telescope ALMA that can clearly image this disk object in such details. Amazing!

    Hasegawa: ALMA was constructed in global partnership of East Asia, North America [NRAO], and the Member States of the European Southern Observatory [ESO]. The total amount funded by Japan was about 250 million US dollars, which accounts for 1/4 of the entire construction costs. To secure such enormous amount of money for construction of ALMA from the national budget, efforts were needed to reduce research budgets allocated to other science projects not limited to the field of astronomy. So, to gain wider-ranging understanding of scientists, we gave explanations like, “This blurry image is the limit of our observation of planet formation at this point. However, if ALMA was constructed, we would be able to see it with 100 times higher resolution and reveal the planet formation process leading to the origin of life, which will be a great contribution not only to astronomy but to the science community as a whole. Could you give us support for it? ”

    — This is why you were so relieved when you saw the first image.

    Hasegawa: Exactly.

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    ALMA Telescope constructed in Chile Credit: Y. Beletsky (LCO)/ESO

    See the full article here .

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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small
    ESO 50 Large
    NAOJ

     
  • richardmitnick 9:06 am on May 13, 2017 Permalink | Reply
    Tags: , Masaaki Hiramatsu, Mysteries of the Universe vol.1, NAOJ   

    From ALMA: “Interview with ALMA Public Outreach Officer : Mysteries of the Universe vol.1 Can Life Exist on Other Planets?” 

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

    2017.05.09
    Interviewed and written by Toshihiro Nakamura
    Photographed by: Nozomu Toyoshima

    Many people are curious about the existence of extraterrestrial life. In fact, we have already started to obtain some evidences of it. With the advancement of astronomy, many planets were found beyond our solar system and ALMA observations have found organic molecules in planet forming regions. These findings all suggest the possible existence of planets with life like our earth.
    One of the scientific goals of ALMA is to explore building blocks of life. What is the likelihood of the existence of Earth-like planets and extraterrestrial life? To find the answer for simple questions like this and know more about the mechanism of the universe, we interviewed with ALMA EPO officer Masaaki Hiramatsu.

    Is there Many Planets with Life in the Universe?

    — How many stars and galaxies have been found in astronomy so far?

    Hiramatsu: Our Earth exists in the Milky Way Galaxy with roughly 100 billion stars. And it is assumed there are several hundreds of billion galaxies in the universe like ours.

    — That means the number of stars in the whole universe would be 100 billion times several hundreds of billion?

    Hiramatsu: Could be, in a simple calculation. I’d like to introduce you this very useful Window’s software (Mitaka). This software reproduces the galaxies and stars that have been found in astronomy in three dimensions with their positional information.

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    The universe around our solar system displayed with MitakaCredit:4D2U Project, NAOJ. All rights reserved.

    — Wow…amazing. This image makes me a little crazy (laugh). Among such an enormous number of stars in the universe, planets with life like the Earth have yet to be found. Is there any chance that it will be found in the future?

    Hiramatsu: We can’t say anything for sure because we only know about the life on earth. But, personally I won’t be surprised even if life is found somewhere in the universe with such a huge number of stars (indicating the screen shown by the application software).

    — What kind of life do you think does exist beyond the Earth? Like aliens that live in more advanced civilizations than ours?

    Hiramatsu: A word of “life” means a variety of forms of life. It ranges from a very simple life like microorganism, higher organism like plants and animals, and intellectual life like human beings. But, regardless of such differences, I have no doubt about the existence of life in large quantities.

    — Why do you think that way?

    Hiramatsu: Because there have been found an increasing number of potential planets that might have life. Extrasolar planets (planets outside our solar system) were found in 1995 for the first time, and since then many planets have been found around stars other than the Sun. It is said that about a half of stars shining in the night sky might have planets. Since a quite number of stars have multiple planets in their own system, I naturally think there might be a quite number of planets with life.

    Hiramatsu: Another discovery by astronomical observations so far is that the universe is filled with building blocks of life.

    — What materials could be the building blocks of life?

    Hiramatsu: For example, amino acids that compose proteins have been found from meteorites fallen on earth too, which suggests possible existence of amino acids outside the Earth.

    Also, in space beyond our solar system, there have been found organic molecules with bonds of carbon and oxygen which make up amino acids. ALMA already captured molecules required for the birth of life such as glycolaldehyde and methanol in planet forming regions. These discoveries are expected to be a key to reveal the origin of life.

    — You mean, simple life could be easily formed from such an abundance of ingredients for life?

    Hiramatsu: We have yet to know what is the probability of the birth of life as a consequence of organic molecules and amino acids bonding together. However, according to the research of life on the Earth, it is confirmed that life can survive in a very severe environment once it occurred.

    — Like what kind of environment would be?

    Hiramatsu: Environment with high temperature, high pressure or high radiation. For example, tardigrades also known as “water bears” thought to be “toughest creatures”. They are tiny animals of 1 mm in length. Reportedly they can withstand high temperature up to 150 degrees Celsius and cold temperature cooled to absolute zero, and high pressure up to 75,000 atmospheres in a state called “anhydrobiosis”. They survive extreme dehydration, high ultraviolet and radioactive rays, and even the vacuum of space for the period of around 10 days.

    — Invincible!! So, this example shows that life, once occurred, can survive severe environment if they are tough.

    Hiramatsu: This is only an assumption based on the research of life on the Earth. To know more about the probability of occurrence of life, further research will be needed in collaboration with other fields of study such as molecular biology.

    See the full article here .

    Please help promote STEM in your local schools.
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    The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Organization for Astronomical Research in the Southern Hemisphere (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan.

    ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

    NRAO Small
    ESO 50 Large
    NAOJ

     
  • richardmitnick 9:25 am on May 1, 2017 Permalink | Reply
    Tags: , , , Chariklo rings, , , NAOJ   

    From EarthSky: “Simulating the smallest ring world’ 

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    EarthSky

    April 30, 2017
    Deborah Byrd

    Chariklo is the smallest space body known to have rings. A new supercomputer simulation by Japanese researchers suggests a life expectancy for the rings of only 1 to 100 years.

    The Center for Computational Astrophysics in New York said on Friday (April 28, 2017) that Japanese researchers have modeled the two known rings around 10199 Chariklo, a possible dwarf planet orbiting the sun between the major planets Saturn and Uranus. They say it’s the first time an entire ring system has been simulated using realistic sizes for the ring particles while also taking into account collisions and gravitational interactions between the particles. They also created the visuals on this page, including the video above, which lets you dive into Chariklo’s ring system. Note that Chariklo itself is really potato-shaped and no doubt pocked with craters; the round, smooth shape in the video is for purposes of the simulation.

    These researchers’ work is published in the peer-reviewed March 2017 edition of The Astrophysical Journal Letters.

    Chariklo is a tiny world.

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    An artist’s rendering of the minor planet 10199 Chariklo, with rings.
    Observations at many sites in South America, including ESO’s La Silla Observatory, have made the surprise discovery that the remote asteroid Chariklo is surrounded by two dense and narrow rings. This is the smallest object by far found to have rings and only the fifth body in the Solar System — after the much larger planets Jupiter, Saturn, Uranus and Neptune — to have this feature. The origin of these rings remains a mystery, but they may be the result of a collision that created a disc of debris. This artist’s impression shows a close-up of what the rings might look like.
    ESO/L. Calçada/M. Kornmesser/Nick Risinger (skysurvey.org)

    Its estimated size about 200 miles (334 km) by about 140 miles (226 km) by about 100 miles (172 km). Our solar system’s major outer planets (Jupiter, Saturn, Uranus, Neptune) all are known to have rings. These planets’ rings are composed of particles estimated to range from inches to several feet (centimeters to meters) in size. Chariklo’s gravitational attraction is small relative to the major planets, so its rings – which were discovered in 2014 – are likely only temporary.

    Although Chariklo is small, and although its gravity is relatively weak, its rings are as opaque as those around Saturn and Uranus. Thus, the researchers said, Chariklo offered an ideal chance to model a complete ring system.

    The team said their simulation revealed information about the size and density of the particles in the rings. They found that Chariklo’s inner ring should be unstable without help. So – the researchers said – the ring particles must be much smaller than previously thought. Or it means that an undiscovered shepherd satellite around Chariklo is stabilizing the ring.

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    Visualization constructed from simulation of Chariklo’s double ring. Note that Chariklo itself is really potato-shaped and no doubt pocked with craters; the round, smooth shape here is for purposes of the simulation. Image via Shugo Michikoshi, Eiichiro Kokubo, Hirotaka Nakayama, 4D2U Project, NAOJ/ CFCA.

    The researchers – Shugo Michikoshi (Kyoto Women’s University/University of Tsukuba) and Eiichiro Kokubo (National Astronomical Observatory of Japan, or NAOJ) modeled Chariklo’s rings using the supercomputer ATERUI*1 at NAOJ. They calculated the motions of 345 million ring particles with the realistic size of a few meters taking into account the collisions and mutual gravitational attractions between the particles.

    Chariklo is the largest member of a class known as the Centaurs, orbiting between Saturn and Uranus in the outer solar system. These bodies are categorized like asteroids, but, whereas most asteroids lie in the asteroid belt between Mars and Jupiter – closer to the sun – Centaurs may have come from the Kuiper Belt, which is visualized as extending from the orbit of the outermost major planet Neptune to approximately 50 Earth-sun units (AU) from our sun. Centaurs have unstable orbits that cross the giant planets’ orbit. Chariklo’s orbit gazes that of Uranus. Because their orbits are frequently perturbed, Centaurs like Chariklo are expected to only remain in their orbits only for millions of years, in contrast to our Earth and the other major planets which have been orbiting for billions of years around our sun.

    The new computer visualization suggests that the density of Chariklo’s ring particles must be less than half the density of Chariklo itself. And they show a striped pattern forming in the inner ring due to interactions between the particles. They use the term “self-gravity wakes” for this pattern (see the image below). These self-gravity wakes accelerate the break-up of the ring, the researchers said.

    But perhaps the most surprising result of the new study is a recalculated life expectancy for Chariklo’s rings. The study suggests the rings may be able to reamin around Chariklo for only one to 100 years! That’s much shorter than previous estimates, and it’s less than an eye-blink in astronomical terms.

    So what we are seeing with Chariklo and its ring system is likely a very temporary and dynamic situation. Things in space tend to happen on a vastly-longer timescales than we humans are used to, but sometimes things do happen on human timescales. Chariklo’s rings may be an example!

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    Simulation of Chariklo’s ring system. The researchers said they used a ring particle density equal to half of Chariklo’s density, in order to maintain the rings’ overall structure. In the close-up view (right) complicated, elongated structures are visible. These structures are called self-gravity wakes. The numbers along the axes indicate distances in km. Image via Shugo Michikoshi / CFCA.

    See the full article here .

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  • richardmitnick 3:54 pm on February 28, 2017 Permalink | Reply
    Tags: , , , COSMOS field as imaged by the Hyper Suprime-Cam, HSC-SSP survey, NAOJ   

    From NAOJ: “First Public Data Release by the Hyper Suprime-Cam Subaru Strategic Program” 

    NAOJ

    NAOJ

    February 27, 2017

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    Figure 1: A color composite image in the g, r and i bands of a small piece of the COSMOS field, as imaged by the Hyper Suprime-Cam. This image contains thousands of galaxies as faint as 27th magnitude. The galaxies are seen at such large distances that the light from them has taken billions of years to reach us. The light from the faintest galaxies was emitted when the universe was less than 10 % of its present age. (Credit: Princeton University/HSC Project)

    Figuring out the fate of the Universe is one step closer. The first massive dataset of a “cosmic census” is released using the largest digital camera on the Subaru Telescope. Beautiful images are available for public at large.

    The first dataset from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) was released to the public on February 27th, 2017. HSC-SSP is a large survey being done using HSC, which is an optical imaging camera mounted at the prime focus of the Subaru Telescope. HSC has 104 scientific CCDs (for a total of 870 million pixels) and a 1.77 square-degree field of view.

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    Figure 2: A HSC-SSP image of a massive cluster of galaxies in the Virgo constellation showing numerous strong gravitational lenses. The distance to the central galaxy is 5.3 billion light years, while the lensed galaxies, apparent as the arcs around the cluster, are much more distant. This is a composite image in the g, r, and i band, and has a spatial resolution of about 0.6 arcsecond. (Credit: NAOJ/HSC Project)

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    Figure 3: A color composite image in the g, r and i bands of UGC 10214 known as Tadpole Galaxy in the ELAIS-N1 region. The distance to this galaxy is about 400 million light years. The long tail of stars made by gravitational interaction due to the galactic encounter is characteristic. (Credit: NAOJ/HSC Project)

    The National Astronomical Observatory of Japan (NAOJ) has embarked on the HSC-SSP survey in collaboration with the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) in Japan, the Academia Sinica Institute of Astronomy and Astrophysics (ASIAA) in Taiwan, and Princeton University in the United States. The project will take 300 nights over 5-6 years. This survey consists of three layers; Wide, Deep, and UltraDeep, using optical and near infrared wavelengths in five broad bands (g, r, i, z, y) and four narrow-band filters.

    This release includes data from the first 1.7 years (61.5 nights of observations beginning in 2014). The observed areas covered by the Wide, Deep, and UltraDeep layers are 108, 26, and 4 square degrees, respectively. The limiting magnitudes, which refer to the depth (Note) of the observations, are 26.4, 26.6 and 27.3 mag in r-band (about 620 nm wavelength), respectively, allowing observations of some of the most distant galaxies in the universe. In the multi-band images, images are extremely sharp, with star images only 0.6 to 0.8 arcseconds across. 1 arcsecond equals 3600th part of a degree. These high-quality data will allow a unprecedented view into the nature and evolution of galaxies and dark matter. This first public dataset already contains 70 million galaxies and stars. It demonstrates that HSC-SSP is making the most of the performance of the Subaru Telescope and HSC. In 2015, using HSC observations over 2.3 square degrees of sky, nine clumps of dark matter, each weighing as much a galaxy cluster were discovered from their weak lensing signature (Miyazaki et al. 2015, ApJ 807, 22, “Properties of Weak Lensing Clusters Detected on Hyper Suprime-Cam 2.3 Square Degree Field”). The HSC-SSP data release covers about 50 times more sky than was used in this study, showing the potential of these data to reveal the statistical properties of dark matter.

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    4a
    4b

    Figure 4: Survey area of HSC-SSP. Blue color shows the area of the Wide layer data included in the data release, green Deep, and red UltraDeep, respectively. (Credit: NAOJ/HSC Project)

    The total amount of data taken so far comprises 80 terabytes, which is comparable to the size of about 10 million images by a general digital camera. Since it is difficult to search such a huge dataset with standard tools, NAOJ has developed a dedicated database and interface for ease of access and use of the data.

    “Since 2014, we have been observing the sky with HSC, which can capture a wide-field image with high resolution,” said Dr. Satoshi Miyazaki, the leader of the HSC-SSP. “We believe the data release will lead to many exciting astronomical results, from exploring the nature of dark matter and dark energy, as well as asteroids in our own solar system objects and galaxies in the early universe. SSP team members are now preparing a number of scientific papers based on these data. We plan to publish them in a special issue of the Publications of Astronomical Society of Japan. Moreover, we hope that interested members of the public will also access the data and enjoy the real universe imaged by the Subaru telescope, one of the largest the world.”

    Funding for the HSC Project was provided in part by the following grants: Grant-in-Aid for Scientific Research (B) JP15340065; Grant-in-Aid for Scientific Research on Priority Areas JP18072003; and the Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST) entitled, “Uncovering the Origin and Future of the Universe: ultra-wide-field imaging and spectroscopy reveal the nature of dark matter and dark energy.”

    Note:

    “Depth” of an observation refers to how dim objects can be studied. The light collection power of large aperture mirror (8.2 m for the Subaru Telescope) is the crucial factor, as well as the exposure time. For astronomical objects of the same intrinsic brightness, depth is literally how far one can look.

    Links:

    HSC-SSP Public data release site
    HSC-SSP Website
    HSC Project Website
    Image of M31 Heralds the Dawn of HSC’s Productivity (July 30, 2013 Subaru Tele-scope Topics)
    Hyper Suprime-Cam Ushers in a New Era of Observational Astronomy (September 12, 2012 Subaru Telescope Topics)

    See the full article here .

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

    NAOJ Subaru Telescope interior
    Subaru

    ALMA Array
    ALMA

    sft
    Solar Flare Telescope

    Nobeyama Radio Telescope - Copy
    Nobeyama Radio Observatory

    Nobeyama Solar Radio Telescope Array
    Nobeyama Radio Observatory: Solar

    Misuzawa Station Japan
    Mizusawa VERA Observatory

    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 4:07 pm on February 2, 2017 Permalink | Reply
    Tags: , , , , , NAOJ, Tail of Stray Black Hole hiding in the Milky Way   

    From NAOJ: “Tail of Stray Black Hole hiding in the Milky Way” 

    NAOJ

    NAOJ

    2017 Feb 02
    No writer credit found

    By analyzing the gas motion of an extraordinarily fast-moving cosmic cloud in a corner of the Milky Way, astronomers found hints of a wandering black hole hidden in the cloud. This result marks the beginning of the search for quiet black holes; millions of such objects are expected to be floating in the Milky Way although only dozens have been found to date.

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    Figure 1. Artist’s impression of a stray black hole storming through a dense gas cloud. The gas is dragged along by the strong gravity of the black hole to form a narrow gas stream. Credit: Keio University

    It is difficult to find black holes, because they are completely black. In some cases black holes cause effects which can be seen. For example if a black hole has a companion star, gas streaming into the black hole piles up around it and forms a disk. The disk heats up due to the enormous gravitational pull by the black hole and emits intense radiation. But if a black hole is floating alone in space, no emissions would be observable coming from it.

    A research team led by Masaya Yamada, a graduate student at Keio University, Japan, and Tomoharu Oka, a professor at Keio University, used the ASTE Telescope in Chile and the 45-m Radio Telescope at Nobeyama Radio Observatory, both operated by the National Astronomical Observatory of Japan, to observe molecular clouds around the supernova remnant W44, located 10,000 light-years away from us. Their primary goal was to examine how much energy was transferred from the supernova explosion to the surrounding molecular gas, but they happened to find signs of a hidden black hole at the edge of W44.

    NAOJ Atacama Submillimeter Telescope Experiment (ASTE)  deployed to its site on Pampa La Bola, near Cerro Chajnantor and the Llano de Chajnantor Observatory in northern Chile
    NAOJ Atacama Submillimeter Telescope Experiment (ASTE) deployed to its site on Pampa La Bola, near Cerro Chajnantor and the Llano de Chajnantor Observatory in northern Chile

    NAOJ Nobeyama Radio Observatory, located near Minamimaki, Nagano at an elevation of 1350m
    NAOJ Nobeyama Radio Observatory, located near Minamimaki, Nagano at an elevation of 1350m

    During the survey, the team found a compact molecular cloud with enigmatic motion. This cloud, named the “Bullet,” has a speed of more than 100 km/s, which exceeds the speed of sound in interstellar space by more than two orders of magnitude. In addition, this cloud, with the size of two light-years, moves backward against the rotation of the Milky Way Galaxy.

    To investigate the origin of the Bullet, the team performed intensive observations of the gas cloud with ASTE and the Nobeyama 45-m Radio Telescope. The data indicate that the Bullet seems to jump out from the edge of the W44 supernova remnant with immense kinetic energy. “Most of the Bullet has an expanding motion with a speed of 50 km/s, but the tip of the Bullet has a speed of 120 km/s,” said Yamada. “Its kinetic energy is a few tens of times larger than that injected by the W44 supernova. It seems impossible to generate such an energetic cloud under ordinary environments.”

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    Figure 3. (a) CO (J=3-2) emissions (color) and 1.4 GHz radio continuum emissions (contours) around the supernova remnant W44. (b) Galactic longitude-velocity diagram of CO (J=3-2) emissions at the galactic latitude of -0.472 degrees. (c -f): Galactic longitude-velocity diagrams of the Bullet in CO (J=1-0), CO (J=3-2), CO (J=4-3), and HCO+ (J=1-0), from left to right. Galactic longitude-velocity diagrams show the speed of the gas at a specific position. Structures elongated in the vertical direction in the diagrams have a large velocity width. Credit: Yamada et al. (Keio University), NAOJ

    The team proposed two scenarios for the formation of the Bullet. In both cases, a dark and compact gravity source, possibly a black hole, has an important role. One scenario is the “explosion model” in which an expanding gas shell of the supernova remnant passes by a static black hole. The black hole pulls the gas very close to it, giving rise to an explosion, which accelerates the gas toward us after the gas shell has passed the black hole. In this case, the astronomers estimated that the mass of the black hole would 3.5 times the solar mass or larger. The other scenario is the “irruption model” in which a high speed black hole storms through a dense gas and the gas is dragged along by the strong gravity of the black hole to form a gas stream. In this case, researchers estimated the mass of the black hole would be 36 times the solar mass or larger. With the present dataset, it is difficult for the team to distinguish which scenario is more likely.

    4
    Figure 4. Schematic diagrams of two scenarios for the formation mechanism of the Bullet. (a) explosion model and (b) irruption model. Both diagrams show a part of the shock front produced by the expansion of the supernova remnant W44. The shock wave enters into quiescent gas and compresses it to form dense gas. The Bullet is located in the center of the diagram and has completely different motion compared to the surrounding gas. Yamada et al. (Keio University)

    Theoretical studies have predicted that 100 million to 1 billion black holes should exist in the Milky Way, although only 60 or so have been identified through observations to date. “We found a new way of discovering stray black holes,” said Oka. The team expects to disentangle the two possible scenarios and find more solid evidence for a black hole in the Bullet with higher resolution observations using a radio interferometer, such as the Atacama Large Millimeter/submillimeter Array (ALMA).

    These observation results were published as Yamada et al. Kinematics of Ultra-high-velocity Gas in the Expanding Molecular Shell adjacent to the W44 Supernova Remnant in the Astrophysical Journal Letters in January 2017.
    The research team members are: Masaya Yamada, Tomoharu Oka, Shunya Takekawa, Yuhei Iwata, Shiho Tsujimoto, Sekito Tokuyama, Maiko Furusawa, Keisuke Tanabe, and Mariko Nomura, from Keio University, Japan.

    This research was supported by a Grant-in-Aid from the Japan Society for the Promotion of Science (No. 15H03643).

    See the full article here .

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

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    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 10:53 am on November 28, 2016 Permalink | Reply
    Tags: , , Extrasolar planet known as K2-3d may be earthlike, NAOJ   

    From NAOJ: “Potentially Habitable Extrasolar Planet Paves the Way to Search for Alien Life” 

    NAOJ

    NAOJ

    November 28, 2016
    No writer credit found

    1
    This collage summarizes the research. Using the Okayama 188-cm Reflector Telescope and the observational instrument MuSCAT (See real photo on the bottom left.), researchers succeeded in observing the extrasolar planet K2-3d, which is about the same size and temperature as the Earth, pass in front of its host star blocking some of the light coming from the star (See artistic visualization at the top.), making it appear to dim (See real data on the bottom right).

    NAOJ Okayama Astrophysical Observatory Telescope a top of Mt. Chikurin-Ji (its elevation is 372 meters) in the southwestern region of Okayama prefecture
    NAOJ okayama Astrophysical Observatory Telescope a top of Mt. Chikurin-Ji (its elevation is 372 meters) in the southwestern region of Okayama prefecture interior
    NAOJ Okayama Astrophysical Observatory Telescope a top of Mt. Chikurin-Ji (its elevation is 372 meters) in the southwestern region of Okayama prefecture.

    A group of researchers from the National Astronomical Observatory of Japan (NAOJ), the University of Tokyo, and the Astrobiology Center among others has observed the transit of a potentially Earth-like extrasolar planet known as K2-3d using the MuSCAT instrument on the Okayama Astrophysical Observatory 188-cm telescope. A transit is a phenomenon in which a planet passes in front of its parent star, blocking a small amount of light from the star, like a shadow of the planet. While transits have previously been observed for thousands of other extrasolar planets, K2-3d is important because there is a possibility that it might harbor extraterrestrial life.

    By observing its transit precisely using the next generation of telescopes, such as TMT, scientists expect to be able to search the atmosphere of the planet for molecules related to life, such as oxygen.

    TMT-Thirty Meter Telescope, proposed for Mauna Kea, Hawaii, USA
    TMT-Thirty Meter Telescope, proposed for Mauna Kea, Hawaii, USA

    With only the previous space telescope observations, however, researchers can’t calculate the orbital period of the planet precisely, which makes predicting the exact times of future transits more difficult. This research group has succeeded in measuring the orbital period of the planet with a high precision of about 18 seconds. This greatly improved the forecast accuracy for future transit times. So now researchers will know exactly when to watch for the transits using the next generation of telescopes. This research result is an important step towards the search for extraterrestrial life in the future.

    The title of the paper is Ground-based Transit Observation of the Habitable-zone Super-Earth K2-3d

    See the full article here .

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

    NAOJ Subaru Telescope interior
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    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 10:47 am on September 8, 2016 Permalink | Reply
    Tags: A supercomputer recreated a blinking impossibly bright “monster pulsar.”, ATERUI Cray XC 30 supercomputer, Center for Computational Astrophysics, NAOJ   

    From NAOJ via Center for Computational Astrophysics, NAOJ: “Avoiding ‘Traffic Jam’ Creates Impossibly Bright ‘Lighthouse’ “ 

    NAOJ

    NAOJ

    1

    9.8.16
    No writer credit found

    A supercomputer recreated a blinking impossibly bright “monster pulsar.”
    The central energy source of enigmatic pulsating Ultra Luminous X-ray sources (ULX) could be a neutron star according to numerical simulations performed by a research group led by Tomohisa Kawashima at the National Astronomical Observatory of Japan (NAOJ).

    1
    Figure1: Artist’s impression of the “New Lighthouse Model.”(Credit: NAOJ)

    ULXs, which are remarkably bright X-ray sources, were thought to be powered by black holes. But in 2014, the X-ray space telescope “NuSTAR” detected unexpected periodic pulsed emissions in a ULX named M82 X-2.

    NASA/NuSTAR
    NASA/NuSTAR

    The discovery of this object named “ULX-pulsar” has puzzled astrophysicists. Black holes can be massive enough to provide the energy needed to create ULXs, but black holes shouldn’t be able to produce pulsed emissions. In contrast, “pulsars,” a kind of neutron star, are named for the pulsed emissions they produce, but they are much fainter than ULXs. A new theory is needed to explain “ULX-pulsar.”

    ULXs are thought to be caused by an object with strong gravity accreting gas from a companion star. As the gas falls towards the object, it collides with other gas. These collisions heat the gas until it gets hot enough to start glowing. The photons (in this case X-rays) emitted by this luminous gas are what astronomers actually observe. But as the photons travel away from the center, they push against the incoming gas, slowing the flow of gas towards the center. This force is called the radiation pressure force. As more gas falls onto the object, it becomes hotter and brighter, but if it becomes too bright the radiation pressure slows the infalling gas so much that it creates a “traffic jam.” This traffic jam limits the rate at which new gas can add additional energy to the system and prevents it from getting any brighter. This luminosity upper limit, at which the radiation pressure balances the gravitational force, is called the Eddington luminosity.

    The Eddington luminosity is determined by the mass of the object. Because pulsars have masses hundreds of thousands of times less than the black holes thought to be powering ULXs, their Eddington luminosities are much lower than what would be needed to account for bright ULXs. But Kawashima and his team started to wonder if there might be a way for pulsars to avoid the traffic jam caused by the Eddington luminosity. “The astrophysicists have been so puzzled,” he explains, “It may be difficult to sustain super-critical accretion onto neutron stars because neutron stars have solid surfaces, unlike black holes. It was a grand challenge to elucidate how to realize super-critical accretion onto neutron stars exhibiting pulsed emissions.”

    For normal pulsars, researchers use an “accretion columns” model where the infalling gas is guided by the pulsar’s strong magnetic field so that it lands on the magnetic poles. If the magnetic pole is misaligned with the neutron star’s rotation axis (much like how ‘magnetic north’ is different from ‘true north’ on Earth), then the location of the magnetic pole will revolve around the rotation axis as the neutron star spins. If the magnetic pole points towards Earth, it appears bright to us, but when it rotates away, the emissions seem to disappear. This is similar to how a lighthouse seems to blink as the direction of its beam rotates.

    In order to address the mystery of ULX-pulsar, Kawashima and his team performed simulations to see if there is some way the accretion columns of gas could flow smoothly without a traffic jam and become hundreds of times brighter than the Eddington luminosity. “No one knew if super-critical column accretion could actually be realized on a neutron star,” explains Shin Mineshige at Kyoto University, “It was a tough problem because we needed to simultaneously solve the equations of hydrodynamics and radiative transfer, which required advanced numerical techniques and computational power.” In the 1970’s, a few astrophysicists briefly addressed the calculation of moderately (not extremely) super-critical accretion columns, however they had to make many assumptions to make the calculations workable. “But thanks to recent developments in techniques and computer resources,” says Ken Ohsuga at NAOJ, “we are now at the dawn of the radiation-hydrodynamic simulations era.” The codes are already used for studies focused on black hole simulations. Thus, prompted by the discovery of ULX-pulsar, this team applied their radiation-hydrodynamic code to simulate super-critical accretion columns onto neutron stars, and carried out the simulations on the NAOJ supercomputer “ATERUI.”

    2
    NAOJ Cray XC30 ATERUI supercomputer

    3
    The new lighthouse model (a snapshot from Movie 1) and simulation results from the present research (inset on the right.) In the simulation results, the red indicates stronger radiation, and the arrows show the directions of photon flow. In this figure, many photons are produced near the surface of the neutron star and escape from the side of the accretion column. (Credit: NAOJ)

    The team found that it actually is possible for the infalling gas to avoid an Eddington luminosity induced traffic jam in super-critical column accretion. In their simulations, the accreting gas forms a shock front near the neutron star. Here, a huge amount of the kinetic energy of the infalling gas is converted to thermal energy. The gas just below the shock surface is rapidly heated by this energy and emits a huge number of photons. But rather than pushing back against the infalling gas as the previous models suggested, the photons are directed out the sides of the column. This means without a traffic jam, more gas can fall in rapidly, be heated by the shock front and produce more photons, so that the process isn’t forced to slow down.

    The NAOJ team’s model can account for the observed characteristics of ULX-pulsar: a high luminosity and directed beams of photons which will appear to blink as the neutron star rotates. Surprisingly, the direction of the photon beams is at a right angle to the polar beams expected in a standard pulsar model. This is the first simulation to support the idea that the central engine of the ULX-pulsar is a neutron star.


    Artist’s impression of the standard model of a pulsar. Photon beams are emitted from the magnetic poles of a neutron star. These photon beams twirl because of the misalignment between the magnetic poles and the rotation axis. As a result, the beams face towards an observer at regular intervals and pulsed emissions are observed coming from the neutron star. (Credit: NAOJ)


    Artist’s impression of the new cosmic lighthouse model. When gases (red) fall onto a neutron star, the accretion columns are heated by shock waves and shine brightly. Photons can escape from the columns through the sidewall and do not prevent additional gas from accreting. Therefore these columns continue to emit an enormous amount of photos. In this model, due to the misalignment between the accretion columns and the rotation axis, the appearance of the accretion columns changes periodically with the rotation of the neutron star. Dazzling pulsed emissions can be observed when the apparent area of the columns reaches maximum. (Credit: NAOJ)

    This team is planning to further develop their work by using this new lighthouse model to study the detailed observational features of the ULX-pulsar M82 X-2, and to explore other ULX-pulsar candidates.

    This research was supported in part by the Japan Society for the Promotion of Science through Grants-in-Aid for Scientific Research (No. 26400229, 15K05036)and MEXT SPIRE and JICFuS as a priority issue (Elucidation of the fundamental laws and evolution of the universe) to be tackled by using the Post K Computer.

    Their paper entitled A radiation-hydrodynamic model of accretion columns for Ultra-luminous X-ray pulsar will appear in Publications of the Astronomical Society of Japan on September 8, 2016.

    (Press Release: September 8, 2016)

    About this research

    Research Team: Tomohisa Kawashima (NAOJ), Shin Mineshige (Kyoto University), Ken Ohsuga (NAOJ), Takumi Ogawa (Kyoto University)

    See the full article here .

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

    NAOJ Subaru Telescope interior
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    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 7:06 am on July 13, 2016 Permalink | Reply
    Tags: , , MIlky Way collision with Andromeda, NAOJ   

    From NAOJ: ” Galactic Merger (II. The Case of Oblique Impact)” 

    NAOJ

    NAOJ

    7.13.16
    No writer credit
    Text from Facebook entry, no link

    The Milky Way Galaxy in which we live and the neighboring Andromeda Galaxy are currently being drawn together through their mutual gravity. It is thought that they will collide in approximately another 4 billion years.

    NAOJ Milky Way merger with Andromeda
    NAOJ Milky Way merger with Andromeda

    This kind of collision between galaxies has actually been observed many times in the Universe. So what happens when galaxies collide? This video is a visualization of simulations performed with a supercomputer for the case of two spiral galaxies colliding obliquely.

    Formation of Giant Star Clusters Resulting from a Galactic Collision

    It’s called a galactic “collision,” but the individual stars within the galaxies don’t collide; they pass each other within the galaxies. But the gas filling the galaxies is compressed into strips where the galaxies collide, and clumps of thick gas form in these regions. Stars form explosively within these gas clouds, and these stars collect to create giant star clusters. Then the two galaxies move past each other, dragging along the star clusters formed by the collision.

    But before long, the two galaxies are pulled back towards each other by their mutual gravity and collide again. And finally they become a single large galaxy. Around the galaxy formed by this merger there are large star clusters which were formed in the first collision. From this simulation we learned that galactic mergers form a far larger mass of star clusters than previously thought.

    http://www.nao.ac.jp/en/gallery/weekly/2016/20160712-4d2u.html

    (YouTube)

    See the full article here .

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

    NAOJ Subaru Telescope interior
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    ESO/NRAO/NAOJ ALMA Array
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    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 11:54 am on March 3, 2016 Permalink | Reply
    Tags: , , Fraunhofer lines of the sun, NAOJ,   

    From NAOJ: “Fraunhofer Lines of the Sun” 

    NAOJ

    NAOJ

    Universe of Spectroscopy

    November 16, 2011 [Presented by NAOJ March 3, 2016]
    Yukio Katsukawa

    Fraunhofer Lines of the Sun Norikura Solar Observatory
    Solar spectra observed by 25cm Cornagraph at Norikura Solar Observatory. The Fraunhofer lines (C, D, E, F, G, H,and K lines) are indicated.

    When you let sunlight pass through a prism, you can see that the light is broken up into the colors of the rainbow (a spectrum). If you observe the spectrum more carefully, you will find countless dark features. These are absorption lines caused by impurities such as calcium, sodium, magnesium, iron, and so on. The chief element of the Sun is hydrogen, and the impurities in minuscule quantities absorb the light coming from the inside at specific wavelengths, resulting in the dark features.

    The Fraunhofer lines are a set of famous absorption lines named after a German physicist. Fraunhofer designated the principal features with the letters A through K from longer wavelength (redder) to shorter (bluer). For example, the D line is caused by sodium, and the H and K lines are caused by calcium. Some Fraunhofer lines were known to originate in absorption in the Earth’s atmosphere.

    The Fraunhofer lines are, indeed, a lifeline of solar physicists. The depths of the absorption lines provide information about temperature, and the wavelength shifts of the lines tell us the motion of gas. If the Sun consisted only of pure hydrogen, there would be no absorption line. This would mean that the researchers could not study the temperature or the motion of the Sun’s atmosphere. This would be the end for them. Thanks to the impurities, we can investigate the Sun in detail.

    3-D Structure of the Sun’s atmosphere

    A dark feature in a spectrum results from absorption of light at a given wavelength. This means a low degree of transparency of the atmosphere at this wavelength. Therefore, we can only observe the outer region of the Sun at this wavelength. We utilize this to study the atmosphere outside the region where we usually observe. The degree of the transparency of the Sun’s atmosphere depends on the absorption lines. Thus, we combine several absorption lines to observe several layers and to study the 3D structure of the Sun’s atmosphere.

    See the full article here .

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

    NAOJ Subaru Telescope interior
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    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
  • richardmitnick 7:51 am on February 23, 2016 Permalink | Reply
    Tags: , , , Dark Matter Halo, NAOJ   

    From NAOJ: “Formation and Evolution of Dark Matter Halos (II. Formation of the Large-Scale Structure of the Universe) 

    NAOJ

    NAOJ

    Dark matter halo
    Visualization of Dark Matter Halo.ESA

    This video is a visualization of the evolution of dark matter distribution from the beginning of the Universe up to the present. Right after the birth of the Universe, dark matter is distributed almost uniformly. But parts with slightly higher densities gravitationally attract the surrounding dark matter to form small halos. Through mergers, these small halos evolve into larger haloes. Within these larger halos gas collects and galaxies form. Furthermore, galaxies group together to form galaxy clusters connected by galaxies distributed in a framework pattern. This is known as the large-scale structure of the Universe.


    Download mp4 video here .

    Exploring the History of Structure Formation in the Universe through Large-Scale Simulations

    In this simulation, the dark matter density distribution at the beginning of the Universe is represented by approximately 8.6 billion particles. The evolution of dark matter halos through mutual gravitational interaction is followed up to the present. By calculating the evolution of the (baryonic) matter, which is the material for stars and galaxies, based on the dark matter distribution obtained through these calculations, it has become possible to predict the distribution, evolution, and statistical characteristics of things like galaxies or active galactic nuclei over a wider area than ever before. Simulation results obtained in this manner can be used as a database to compare with wide field observations performed in the future by facilities like the Subaru Telescope.

    See the full article here .

    Please help promote STEM in your local schools.

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    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

    NAOJ Subaru Telescope

    NAOJ Subaru Telescope interior
    Subaru

    ALMA Array
    ALMA

    sft
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    Nobeyama Radio Telescope - Copy
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    Nobeyama Radio Observatory: Solar

    Misuzawa Station Japan
    Mizusawa VERA Observatory

    NAOJ Okayama Astrophysical Observatory Telescope
    Okayama Astrophysical Observatory

    The National Astronomical Observatory of Japan (NAOJ) is an astronomical research organisation comprising several facilities in Japan, as well as an observatory in Hawaii. It was established in 1988 as an amalgamation of three existing research organizations – the Tokyo Astronomical Observatory of the University of Tokyo, International Latitude Observatory of Mizusawa, and a part of Research Institute of Atmospherics of Nagoya University.

    In the 2004 reform of national research organizations, NAOJ became a division of the National Institutes of Natural Sciences.

     
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