SDSS Science blog bloc

Science Blog from the SDSS

July 31, 2016
Zheng Zheng

This weekend, the Sloan Digital Sky Survey (SDSS) is celebrating its thirteenth public data release, or lucky DR13!

Data releases are an important part of the SDSS. All the data that are observed by the Sloan Telescope for the various surveys that are part of SDSS, get reduced and processed, and eventually are made publicly available. This means that everyone with access to the internet can download the data, use it for their research or teaching, or simply look at all the images and spectra that are available. You just have to go to the SDSS website, and you can start exploring the data for yourself!

So, what does DR13 have in store for you? Apart from including all the data that was released in previous data releases, there is also lots of new data:

DR13 is the first data release for the MaNGA survey! MaNGA stands for Mapping Nearby Galaxies at Apache Point Observatory, and it studies galaxies with integral-field spectroscopy. This allows us to study chemical elements and motions of stars and gas not just in the centre of the galaxies, but all over the galaxy outskirts too. MaNGA is releasing its spectra in datacubes for 1351 individual galaxies, making it the biggest integral-field galaxy survey available on-line so far!

APOGEE, or the APO Galaxy Evolution Experiment is taking infra-red spectra for hundreds of thousands of stars in the Milky Way. For this data release, they have improved the analysis of all their previously released spectra, and measured the abundances of various chemical elements of stars. This will help us understand how the Milky Way formed over time.

eBOSS, short for extended Baryon Oscillation Spectroscopic Survey, is mapping the structure of the Universe, by taking spectra of more than a million galaxies and quasars. Its goal is to measure the expansion rate of the Universe, and the nature of the mysterious Dark Energy that accelerates this expansion. eBOSS is releasing improved analysis of previously released spectra, as well as several catalogs with information on emission line galaxies and variable quasars.

Do you want to have a look at all of this data? Here are some places to get started:

The SDSS SkyServer has several tools to explore the data. You can for instance:
find stars and galaxies in the Navigate tool
look at images and spectra of stars and galaxies with the QuickLook tool
search for a particular sample of galaxies or stars with SQL

If you are interested in analyzing the data yourself, then you can find more information on how to download the data on the SDSS data access page

If you are a teacher and interested in activities that will help your students explore the Universe, then have a look at our SDSS education web page, with lots of resources for the class room.

Anne-Marie Weijmans
SDSS Data Release Coordinator
University of St Andrews

See the full article here .

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After nearly a decade of design and construction, the Sloan Digital Sky Survey saw first light on its giant mosaic camera in 1998 and entered routine operations in 2000. While the collaboration and scope of the SDSS have changed over the years, many of its key principles have stayed fixed: the use of highly efficient instruments and software to enable astronomical surveys of unprecedented scientific reach, a commitment to creating high quality public data sets, and investigations that draw on the full range of expertise in a large international collaboration. The generous support of the Alfred P. Sloan Foundation has been crucial in all phases of the SDSS, alongside support from the Participating Institutions and national funding agencies in the U.S. and other countries.

The Sloan Digital Sky Survey has created the most detailed three-dimensional maps of the Universe ever made, with deep multi-color images of one third of the sky, and spectra for more than three million astronomical objects.

In its first five years of operations, the SDSS carried out deep multi-color imaging over 8000 square degrees and measured spectra of more than 700,000 celestial objects. With an ever-growing collaboration, SDSS-II (2005-2008) completed the original survey goals of imaging half the northern sky and mapping the 3-dimensional clustering of one million galaxies and 100,000 quasars. SDSS-II carried out two additional surveys: the Supernova Survey, which discovered and monitored hundreds of supernovae to measure the expansion history of the universe, and the Sloan Extension for Galactic Understanding and Exploration (SEGUE), which extended SDSS imaging towards the plane of the Galaxy and mapped the motions and composition of more than a quarter million Milky Way stars.

SDSS-III (2008-2014) undertook a major upgrade of the venerable SDSS spectrographs and added two powerful new instruments to execute an interweaved set of four surveys, mapping the clustering of galaxies and intergalactic gas in the distant universe (BOSS), the dynamics and chemical evolution of the Milky Way (SEGUE-2 and APOGEE), and the population of extra-solar giant planets (MARVELS).

The latest generation of the SDSS (SDSS-IV, 2014-2020) is extending precision cosmological measurements to a critical early phase of cosmic history (eBOSS), expanding its revolutionary infrared spectroscopic survey of the Galaxy in the northern and southern hemispheres (APOGEE-2), and for the first time using the Sloan spectrographs to make spatially resolved maps of individual galaxies (MaNGA).

This is the “Science blog” of the SDSS. Here you’ll find short descriptions of interesting scientific research and discoveries from the SDSS. We’ll also update on activities of the collaboration in public engagement and other arenas. We’d love to see your comments and questions about what you read here!

You can explore more on the SDSS Website.