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Sloan digital sky survey galaxies

Sloan digital sky survey galaxies


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I am trying to get some data from the Sloan digital sky survey (SDSS). This task turned out to be challenging for me as someone with only little knowledge about astronomy and maybe someone here can help me. What I need is data for all galaxies of the SDSS with their optical spectroscopy and position.

I suppose I need:

  • redshifts
  • RA (right ascension)
  • dec (declination)
  • classifications of all SDSS spectra

from the Optical Spectra Catalog Data

I found a script to convert ra/dec/redshift to x/y/z coordinates. Will I need "the associated photometric position based matches" and "stellar parameter (SSPP) results" to get RA and dec? I have no idea what these are.


Use the Optical Spectra Query Form. You'll want to set PRIMTARGET to "GALAXY". Here's the list of possible parameters it can return http://skyserver.sdss3.org/dr10/en/help/docs/QS_UserGuide.aspx#Spectroscopy. Note, there is a query limit of 500,000 rows, so you'll have to break up the query since you'll have more spectra than that.


Sloan digital sky survey galaxies - Astronomy

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%T Sloan Digital Sky Survey: Galaxies - Basic
%D February 21, 2007
%I Sloan Digital Sky Survey
%C Seattle
%U http://cas.sdss.org/dr5/en/proj/basic/galaxies/
%O text/html

%0 Electronic Source
%D February 21, 2007
%T Sloan Digital Sky Survey: Galaxies - Basic
%I Sloan Digital Sky Survey
%V 2021
%N 26 June 2021
%8 February 21, 2007
%9 text/html
%U http://cas.sdss.org/dr5/en/proj/basic/galaxies/

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Published Paper for Data Release 9

Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III web site is http://www.sdss3.org/.

SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, University of Cambridge, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University.


Sloan digital sky survey galaxies - Astronomy

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%Q Sloan Digital Sky Survey
%T Sloan Digital Sky Survey: Galaxies - Advanced
%D February 16, 2007
%U http://skyserver.sdss.org/dr1/en/proj/advanced/galaxies/
%O text/html

%0 Electronic Source
%A Sloan Digital Sky Survey,
%D February 16, 2007
%T Sloan Digital Sky Survey: Galaxies - Advanced
%V 2021
%N 26 June 2021
%8 February 16, 2007
%9 text/html
%U http://skyserver.sdss.org/dr1/en/proj/advanced/galaxies/

Disclaimer: ComPADRE offers citation styles as a guide only. We cannot offer interpretations about citations as this is an automated procedure. Please refer to the style manuals in the Citation Source Information area for clarifications.

The AIP Style presented is based on information from the AIP Style Manual.

The APA Style presented is based on information from APA Style.org: Electronic References.

The Chicago Style presented is based on information from Examples of Chicago-Style Documentation.


Sloan digital sky survey galaxies - Astronomy

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ComPADRE is beta testing Citation Styles!

%T Sloan Digital Sky Survey: Galaxies - Basic
%D February 21, 2007
%I Sloan Digital Sky Survey
%C Seattle
%U http://cas.sdss.org/dr5/en/proj/basic/galaxies/
%O text/html

%0 Electronic Source
%D February 21, 2007
%T Sloan Digital Sky Survey: Galaxies - Basic
%I Sloan Digital Sky Survey
%V 2021
%N 26 June 2021
%8 February 21, 2007
%9 text/html
%U http://cas.sdss.org/dr5/en/proj/basic/galaxies/

Disclaimer: ComPADRE offers citation styles as a guide only. We cannot offer interpretations about citations as this is an automated procedure. Please refer to the style manuals in the Citation Source Information area for clarifications.

The AIP Style presented is based on information from the AIP Style Manual.

The APA Style presented is based on information from APA Style.org: Electronic References.

The Chicago Style presented is based on information from Examples of Chicago-Style Documentation.


SDSS-IV

SDSS began regular survey operations in 2000 and it has progressed through several phases: SDSS-I (2000-2005), SDSS-II (2005-2008), SDSS-III (2008-2014), and SDSS-IV (2014-2020). Each of these has involved multiple surveys with interlocking science goals. Over the years, astronomers have used SDSS data to make numerous discoveries related to the nature of the Universe at all scales. SDSS-IV will extend precision cosmological measurements to a critical early time in cosmic history, expand its revolutionary infrared spectroscopic survey of the Milky Way in the northern and southern hemispheres, and for the first time use the Sloan spectrographs to make spatially resolved maps of individual galaxies.


Sloan Digital Sky Survey

About

The Sloan Digital Sky Survey (SDSS) is one of the largest, most detailed, and most often cited astronomical surveys that has ever existed, with the goal of expanding our understanding of the large-scale evolution and structure of the universe, the formation of stars and galaxies, the history of the Milky Way, the nature of supermassive black holes, and the science behind dark energy. By comprehensively mapping and across over a third of the night sky, SDSS represents one of the major quests of contemporary physics and has spurred advancement on answering a range of fundamental questions about the origins of the universe.

By supporting the Astrophysical Research Consortium for over 25 years, the Sloan Foundation has helped to build and operate the pioneering Sloan Foundation Telescope at Apache Point Observatory in New Mexico and conduct experiments to observe millions of stars, galaxies, quasars, and other cosmological phenomena. The current fifth phase of SDSS, SDSS-V, is led by Director Juna Kollmeier and includes a partnership with the Carnegie Observatories to conduct a full set of observations across both hemispheres with the utilization of the Irénée du Pont Telescope at Las Campanas Observatory in Chile. SDSS-V represents the next major wave of the collaboration’s scientific and technological advancement and innovation, including upgrades to a state-of-the-art robotic observation system.

SDSS remains distinctive within the astronomical community for its participatory, bottom-up scientific research planning process. SDSS-V currently includes over 40 contributing institutional partners who are formal members of this phase of the collaboration, and SDSS-V has received financial support from the National Science Foundation, Heising-Simons Foundation, and the Simons Foundation. SDSS is committed to making advancements with respect to diversity, equity, and inclusion. With support from the Sloan Foundation, SDSS has developed its Faculty and Student Team (FAST) Initiative to involve greater numbers of under-represented students and faculty of color in the collaboration.

All SDSS data is eventually released in full to the entire astronomy community and the broader public under open use principles. In the mostly recently completed fourth phase of SDSS (SDSS-IV), scientists participating in the collaboration have written nearly 1,500 papers using SDSS data, with over 26,000 citations. A total of nearly 10,000 papers with over 500,000 citations have been produced over the course of SDSS’s history when the use of public data releases is included. SDSS is currently the Foundation’s longest running scientific research program.


Yale astronomers to benefit from new Sloan Digital Sky Survey data

As a full institutional partner in the Sloan Digital Sky Survey, Yale will have a first look at data collected from the five-year-long survey before it is released to the public.

Sophie Henry, Staff Illustrator

The Sloan Digital Sky Survey, the most in-depth three-dimensional astronomical survey ever conducted, is ready to enter its fifth phase, giving Yale astronomers a new view of the universe.

SDSS maps out areas of the sky in detail with ground telescopes and determines the brightness and position of millions of objects in the universe. As a full institutional partner of the SDSS collaboration, Yale is guaranteed access to data collected by the survey before it is formally released to the public, giving Yale astronomers a head start in their research.

According to Robert Zinn GRD ’74, professor of astronomy at Yale, previous SDSS data accounts for the majority of astronomers’ understanding of the universe, offering insights into far reaches of the cosmos as well as nearby stars and galaxies. This fifth phase of the project, SDSS-V, began operations last September and will collect spectroscopic data — information from visible light split into its electromagnetic wavelengths — from types of previously observed objects, including supermassive black holes and galaxies.

“This survey will be collecting data on many more objects of these types than we have previously,” said Zinn, whose research focuses on galaxy structure and formation. “[SDSS-V] will be expanding the sample tremendously, and as you expand this sample there is a real possibility of a new discovery.”

Yale was a full institutional partner of SDSS-III, which mapped the sky from 2008 to 2014, and SDSS-IV, which operated from 2014 to 2020, according to Meg Urry, professor of physics and astronomy. Each survey involves the collaboration of hundreds of astronomers and institutions around the world, and with each new phase, increasingly sophisticated instruments are used to guarantee high quality data, according to Zinn. For SDSS-V, the collaboration will involve two telescopes. One is located at the Apache Point Observatory in New Mexico, and the other is located at Las Campanas Observatory in Chile.

The benefits of being a full institutional partner of the collaboration include early access to the data for any student, faculty or postdoctoral student associated with one of the partner institutions. Affiliates can view the data as soon as it is collected, and the data is released to the general public approximately a year later.

Urry is one of the many astronomers involved in the SDSS project and has served on the advisory committee for both SDSS-III and SDSS-IV. She now sits on the executive committee for SDSS-V. Urry said that the pandemic has had a “severe impact” on the survey, delaying the project’s transition into the fifth phase.

She explained that last spring, the SDSS executive board approved an indefinite delay of the transition at the early onset of the pandemic but had hoped to restart operations soon afterward. But as public health restrictions increased, the project was further delayed. The transition from SDSS-IV to SDSS-V was supposed to occur in early 2020 but was pushed to September.

Urry’s research focuses on supermassive black holes, which reside at the centers of galaxies. For this reason, she is especially interested in the SDSS Black Hole Mapper experiment. The experiment will obtain spectra — wavelengths of light produced after electromagnetic radiation is split through a prism — from approximately 400,000 X-ray sources, primarily black holes. Researchers will perform this experiment with the eROSITA satellite, which was launched in 2019. Urry explained that this new spectrographic data will increase astronomers’ current understanding of the growth of supermassive black holes, as well as their effect on their host galaxies.

Marla Geha, professor of astronomy and physics and the director of the Astronomy Department’s facilities, is one of the astronomers interested in the SDSS Milky Way Mapper project, which will observe four to five million stars in the Milky Way galaxy.

At Yale, Geha’s research is focused on the origin and evolution of dwarf galaxies, and now that SDSS is releasing in-depth data on stars in the Milky Way, she is looking forward to the data release.

“SDSS data has enabled or improved almost all aspects of my research,” Geha wrote in an email to the News. “I am using SDSS-based imaging to determine the properties of these stars and noting those stars which SDSS has already studied in more detail with spectroscopy.”

Zinn told the News that data collected from previous phases of the SDSS have been invaluable to the astronomical community. He expects that this fifth phase will bring even more high quality data that will inspire groundbreaking research.

“I think all observational astronomers, and many theorists, have used the data from previous Sloan surveys in their research because there is a wealth of information there,” Zinn said. “And even though the people inside the consortium get first shot at it, a few years down the road after the data is published it is still possible to make discoveries from it.”

Data from SDSS-V will be released in the summer of 2022, two years after its launch.


Largest Map of Universe Yet Captures 1 Million Galaxies

The largest 3D map yet of the universe's huge galaxies and bright black holes may serve as a springboard toward solving some of astronomy's greatest mysteries, its creators say.

The map, which was released Wednesday (Aug. 8), uses new data to reveal the locations of more than a million galaxies over a total volume of 70 billion cubic light-years. (A light-year is the distance light travels in one year — about 6 trillion miles, or 10 trillion kilometers.)

David Schlegel of Lawrence Berkeley National Laboratory in California said this kind of atlas could help scientists get to the bottom of perplexing mysteries such as the invisible, untouchable dark matter and dark energy that seem to be rampant in space.

"Dark matter and dark energy are two of the greatest mysteries of our time," Schlegel said in a statement issued with the map's release. "We hope that our new map of the universe can help someone solve the mystery."

The new data come from the Sloan Digital Sky Survey III (SDSS-III), and they include measurements from the ongoing SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS), which calculates the distances to galaxies as far as 6 billion light-years away and humongous black holes that lie up to 12 billion light-years from Earth.

The SDSS-III project publically released a large amount of its data, including the map, for use by astronomers around the world in their own studies.

"Our goal is to create a catalog that will be used long after we are done," said Michael Blanton of New York University, who led the team that prepared the data release.

The release contains photos of 200 million galaxies and spectra (measurements where an object's light is split into its constituent wavelengths) of 1.35 million galaxies.

"We want to map the largest volume of the universe yet, and to use that map to understand how the expansion of the universe is accelerating," said Daniel Eisenstein of the Harvard-Smithsonian Center for Astrophysics, the director of SDSS-III.

Scientists think the prevalence of dark energy in the universe is the force causing space to accelerate in its expansion to a greater and greater volume.


Sloan digital sky survey galaxies - Astronomy

CONTACTS:
Daniel Zucker, Max Planck Institute for Astronomy, Heidelberg, Germany, [email protected]
Eric Bell, Max Planck Institute for Astronomy, [email protected]
Michael A. Strauss, SDSS Scientific Spokesperson, (609) 258-3808, [email protected]
IMPORTANT NOTE: On May 31 and June 1, Zucker and Bell will be attending the AMERICAN ASTRONOMICAL SOCIETY meeting in Denver and can be reached immediately following their panel presentation through the AAS Press Room at 303 228-8370 (three lines) FAX 303 228-8373

DENVER (May 31, 2004) -- A team of astronomers from the Sloan Digital Sky Survey (SDSS) collaboration has discovered the faintest galaxy yet -- right in our cosmic backyard.

The new galaxy, named Andromeda IX for its location near M31, the Andromeda galaxy, is nearly twice as faint as the previous record holder, and is so diffuse that it appears 100 times dimmer than the night sky.

This figure shows Andromeda IX, the least luminous galaxy yet discovered. Most of the stars in this image are foreground stars from the Milky Way Andromeda IX is barely visible as the slight concentration of faint stars in the center of the image. Andromeda IX is some 100,000 times fainter than M31 (also called the Andromeda Galaxy) or the Milky Way, has a diameter of roughly 3,000 light years, and lies at a distance of 2 million light years from the Sun. CREDIT: Daniel Zucker The Sloan Digital Sky Survey. Imaging data for the lower center panel was taken from from Isaac Newton Groups' Wide Field Camera Survey (www.ing.iac.es), Nial Tanvir.)
(Click on image to enlarge)
SDSS scientist Daniel Zucker and SDSS collaboration member Eric Bell, both of the Max Planck Institute for Astronomy in Heidelberg, announced the findings today at the American Astronomical Society's meeting in Denver during a presentation on "REMARKABLE GALAXIES."

"Traditional galaxy searches are not sensitive enough to detect such objects, so instead we looked for clumpings of faint stars and found this incredibly dim galaxy right next to M31," explains Zucker. M31, at a distance of 2 million light years, is the closest large galaxy to our own Milky Way galaxy, and is barely visible to the naked eye from the northern hemisphere during the autumn months.

(Lower Left): This panel shows the relative density of faint stars in a small region of the scan highlighted above the bright, high-density clump of stars in the center reveals the location of Andromeda IX.

(Lower Center): This panel shows a zoomed-in image of Andromeda IX, barely visible as the slight concentration of stars in the center of the panel. Most of the bright stars are in fact foreground stars from the Milky Way, and are unrelated to Andromeda IX. Traditional search techniques would have difficulty in detecting Andromeda IX directly.

(Lower right): A section of the outer disk of M31, covering the same area as the Andromeda IX inset. Andromeda IX is clearly much smaller and fainter than M31.

CREDIT: Daniel Zucker The Sloan Digital Sky Survey. Imaging data for the lower center panel was taken from from Isaac Newton Groups' Wide Field Camera Survey (www.ing.iac.es), Nial Tanvir.

The SDSS telescope is unique in its ability to discover extremely dim galaxies like the one announced today. Rather than studying a point in the sky, the 2.5-meter optical telescope scans a horizon-to-horizon swath each night. Its camera uses charged coupled devices (CCDs) -- ultra-sensitive versions of the electronic detectors found in digital cameras -- which turn light into digital signals in five different wavelengths.

"SDSS is able to find really quite faint objects," explains Bell. "The mapping is incredibly efficient -- typically by a factor of 10 to 100 faster than other telescopes. It is mapping very faint objects over an enormous area on the sky, allowing very rare classes of galaxies to be discovered. Since Andromeda IX is both rare and faint, the SDSS telescope and camera were excellent tools for finding it."

Once they had discovered Andromeda IX, the researchers used both the SDSS data and older archival images to investigate its properties. While Andromeda IX has many of the characteristics of a dwarf spheroidal galaxy -- a class of small, relatively faint, oval-shaped galaxies typically found as satellites of larger galaxies -- it is significantly fainter and more diffuse than any found to date.

The Ursa Minor dwarf spheroidal galaxy, a satellite of the Milky Way, was previously considered to be the faintest galaxy known, but with a total luminosity of some 200,000 Suns, Andromeda IX is about two times fainter than Ursa Minor and 100,000 times fainter than the Milky Way. What's more, the relatively few stars in Andromeda IX are spread over a region with a diameter of about 3,000 light years, which makes Andromeda IX also the most diffuse galaxy known.

But the discovery of Andromeda IX is not just interesting for setting a record. It may also point the way to solving a major mystery in modern astronomy -- the "missing satellites" problem.

The leading theoretical models for how large structures -- galaxies and clusters of galaxies -- formed in the Universe employ a concept called dark matter. Dark matter can only be detected via its gravitational pull, neither emitting nor reflecting light (hence the "dark" in its name).

The models hold that this dark matter began clumping together soon after the Big Bang, while the normal matter was still too hot to come together. Smaller clumps of dark matter merged to form larger and larger clumps, and when the normal visible matter had cooled sufficiently to "feel" the gravitational pull of the dark matter, it collapsed onto these dark matter clumps. In this way, the dark matter clumps acted as seeds for galaxy formation.

The problem is that the models also predict large galaxies should have something like 100 times more small galaxy companions, each associated with a clump of dark matter, than have been seen to date. The discovery of Andromeda IX raises the possibility these galaxies could simply be too faint and diffuse to have been detected in previous surveys.

"The wide area coverage and excellent sensitivity of the SDSS data are truly unprecedented, and have enabled us to find incredibly faint objects like Andromeda IX and Andromeda NE from their component stars, rather than by their total light," notes SDSS discovery collaborator Eva Grebel of the University of Basel, Switzerland. (Andromeda NE can be seen at www.sdss.org/news/releases/20040105.andromeda.html )

Using the same analysis techniques, the astronomers have found a number of additional clumps of objects. "These are possibly clusters of distant galaxies yet if even a few of these turn out to be nearby faint galaxies, they could go a long way toward solving the missing satellites problem," adds Alexei Kniazev, of the Max Planck Institute. "We need more data to be sure."

In addition to SDSS scientists at the Max Planck Institute and the Astronomical Institute of the University of Basel, the international group discovering Andromeda IX includes SDSS collaborators from the University of Washington, Seattle, and New Mexico State University in Las Cruces.


All Science Journal Classification (ASJC) codes

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Early-type galaxies in the sloan digital sky survey. II. Correlations between observables. / Bernardi, Mariangela Sheth, Ravi K. Annis, James Burles, Scott Eisenstein, Daniel J. Finkbeiner, Douglas P. Hogg, David W. Lupton, Robert H. Schlegel, David J. SubbaRao, Mark Bahcall, Neta A. Blakeslee, John P. Brinkmann, J. Castander, Francisco J. Connolly, Andrew J. Csabai, István Doi, Mamoru Fukugita, Masataka Frieman, Joshua Heckman, Timothy Hennessy, Gregory S. Ivezić, Željko Knapp, R. Lamb, Don Q. McKay, Timothy Munn, Jeffrey A. Nichol, Robert Okamura, Sadanori Schneider, Donald P. Thakar, Aniruddha R. York, Donald G.

In: Astronomical Journal , Vol. 125, No. 4 1768, 01.04.2003, p. 1849-1865.

Research output : Contribution to journal › Review article › peer-review

T1 - Early-type galaxies in the sloan digital sky survey. II. Correlations between observables

AU - Castander, Francisco J.

N2 - A magnitude-limited sample of nearly 9000 early-type galaxies, in the redshift range 0.01 ≤ z ≤ 0.3, was selected from the Sloan Digital Sky Survey using morphological and spectral criteria. The sample was used to study how early-type galaxy observables, including luminosity L, effective radius Ro, surface brightness Io, color, and velocity dispersion σ, are correlated with one another. Measurement biases are understood with mock catalogs that reproduce all of the observed scaling relations and their dependences on fitting technique. At any given redshift, the intrinsic distribution of luminosities, sizes, and velocity dispersions in our sample are all approximately Gaussian. A maximum, likelihood analysis shows that σ ∝ L0.25±0.012, Ro ∝ L 0.63±0.025, and Ro ∝ I -0.075±0.02 in the r* band. In addition, the mass-to-light ratio within the effective radius scales as Mo/L 0.14±0.02 or Mo/L ∝ Mo 0.22±0.05, and galaxies with larger effective masses have smaller effective densities: Δo Mo -0.52±0.03. These relations are approximately the same in the g*, i*, and z* bands. Relative to the population at the median redshift in the sample, galaxies at lower and higher redshifts have evolved only little, with more evolution in the bluer bands. The luminosity function is consistent with weak passive luminosity evolution and a formation time of about 9 Gyr ago.

AB - A magnitude-limited sample of nearly 9000 early-type galaxies, in the redshift range 0.01 ≤ z ≤ 0.3, was selected from the Sloan Digital Sky Survey using morphological and spectral criteria. The sample was used to study how early-type galaxy observables, including luminosity L, effective radius Ro, surface brightness Io, color, and velocity dispersion σ, are correlated with one another. Measurement biases are understood with mock catalogs that reproduce all of the observed scaling relations and their dependences on fitting technique. At any given redshift, the intrinsic distribution of luminosities, sizes, and velocity dispersions in our sample are all approximately Gaussian. A maximum, likelihood analysis shows that σ ∝ L0.25±0.012, Ro ∝ L 0.63±0.025, and Ro ∝ I -0.075±0.02 in the r* band. In addition, the mass-to-light ratio within the effective radius scales as Mo/L 0.14±0.02 or Mo/L ∝ Mo 0.22±0.05, and galaxies with larger effective masses have smaller effective densities: Δo Mo -0.52±0.03. These relations are approximately the same in the g*, i*, and z* bands. Relative to the population at the median redshift in the sample, galaxies at lower and higher redshifts have evolved only little, with more evolution in the bluer bands. The luminosity function is consistent with weak passive luminosity evolution and a formation time of about 9 Gyr ago.


Watch the video: Ο άνθρωπος μέσα από τα μάτια της αστροφυσικής. Pavlos Kastanas. TEDxTechnicalUniversityofCrete (June 2022).


Comments:

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