SDSS Plates as Art in Nashville, Tennessee

Check out these cool art pieces made from SDSS spectroscopic plates!  Nashville based artist, Adrienne Outlaw, designed and built them and they will be exhibited in various locations at Vanderbilt University over the next year. The pictures show their first installation, just in time for the Inclusive Astronomy meeting that started yesterday. The concept design was done by Adrienne Outlaw in collaboration with Vanderbilt astronomers David Weintraub and Billy Teets, and the project was funded by Vanderbilt University’s Curb Creative Campus program.

If you want to learn more about what these plates are, and see them in other art installations please see this previous post on SDSS plates.

We love seeing images of SDSS plates around the world. Please send any you find to us via social media (you can find us on Facebook, Twitter and Google+), or email to outreach ‘at’ sdss.org.

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SDSS at the New York Hall of Science

A few months ago (at the end of March), SDSS Members spent a Saturday taking part in the Big Data Fest at the New York Hall of Science, in Queens, NY.

This event was aimed at helping people find out how data is relevant to their lives and featured interactive experiences focused on data literacy and data gathering and visualization.

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Chang Hahn and Yuqian Liu from NYU ready to go with the SDSS booth

Seven SDSS members in total helped out – six from NYU (Chang Hahn, Yuqian Liu, Nitya Mandyam Doddamane, Kilian Walsh, Ben Weaver, and Mike Blanton), along with Guang Yang who travelled up from Penn State University (PSU). This group ran one of about a dozen booths spread throughout the Hall of Science buildings in between the regular exhibits.

The SDSS booth contained an SDSS plate, along with a large-scale printout of the imaging for the part of the sky it was designed for. There was also a set of flash cards with images of galaxies on them, next to an invitation to try classifying them. Visitors were invited to take a card home with them if they wished. There were laptops running both Galaxy Zoo and the SDSS SkyServer. The SkyServer demo was set up to allow visitors to explore the data taken with the plate on display. Finally a monitor displayed a loop of videos about SDSS from the SDSS YouTube Channel.

Galaxy flashcards ready for classifying.

Galaxy flashcards ready for classifying.

The audience were made up of a mixture of children, teenagers and adults (including some who were very scientifically literate). The location in Queens meant that it was mostly NY area residents – with fewer tourists than Manhatten based museums attract.

Nitya Mandyam Doddamane and Yuqian Liu talks about SDSS with some visitors, while Chang Hahn is running a demo of Skyserver.

Nitya Mandyam Doddamane and Yuqian Liu talks about SDSS with some visitors, while Chang Hahn is running a demo of Skyserver.

This event at the NY Hall of Science is just one example of SDSS scientists around the world working to engage members of the public with our data. If you are running a similar event and might be interested in seeing if SDSS would be able to participate, please contact outreach ‘at’ sdss.org and we will try to connect you with your nearest SDSS institution.

How SDSS Used Light to Make the Largest Ever Image of the Night Sky

The Sloan Digital Sky Survey imaged over 30% of the sky between the years of 1998-2008, creating the largest digital colour image of the sky ever taken. To view all of the SDSS imaging at once, would require 500,000 HD televisions (so it can be displayed at full resolution), and with more than a trillion pixels, this image dwarfs the 1.5 billion pixel image that NASA recently claimed was the biggest ever taken.

The SDSS Camera which took all of this imaging is now retired, and was collected by the Smithsonian Institution, to be packed away in a basement as an “artifact of scientific significance”.

The SDSS Camera in its current home - a basement of the Smithsonian Museum in Washington, D.C. Image Credit: Xavier Poultney, SDSS.

The SDSS Camera in its current home – a basement of the Smithsonian Museum in Washington, D.C. Image Credit: Xavier Poultney, SDSS.

The SDSS camera was made by arranging together an array of thirty, 2048×2048 pixel CCD chips. In the 1990s this was state-of-the-art, and even today a 126 Megapixel camera is nothing to sniff at (e.g the current state-of-the-art is DECam which has 62 CCDs and a total of 520 Megapixels).

The CCD chips in the SDSS camera were aligned in five columns, each covered by one of the five filters used to make the colour imaging (the u-, g-, r-, i- and z-bands, roughly corresponding to collecting light in the near-ultraviolet, green, red, near-infrared and a bit less near-infrared respectively).

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An illustration of the arrangement of the CCDs and filters on the camera. The filters from top to bottom are r, i, u, z and g-band. Image credit: SDSS.

This arrangement meant that the camera could take images continuously as the Earth rotated and moved it with respect to the sky overhead. SDSS images are therefore arranged in long stripes of constant Declination across the sky (the most famous being “Stripe 82” which was imaged many times). You can make out some of these stripes around the edges of the stitched together image (the “legs of the orange spider” below).

Orange Spider! This illustration shows the SDSS imaging on many scales. The picture in the top left shows the SDSS view of a small part of the sky, centered on the galaxy Messier 33 (M33). The middle and right top pictures are further zoom-ins on M33. The figure at the bottom is a map of the whole sky derived from the SDSS image. Visible in the map are the clusters and walls of galaxies that are the largest structures in the entire universe. Figure credit: M. Blanton and SDSS

All SDSS imaging is publicly available and can be explored online via the SDSS Skyserver. The Navigate Tool is especially fun as you can scroll around the entire image.

A much more technical description of the camera can be found in Gunn et al. (1998) and in the SDSS-I project book.


This post is part of the SDSS Celebration of the International Year of Light 2015, in which we aim to post an article a month about how SDSS uses light in our mission to study the Universe. 

SDSS Plates for Education

Here at SDSS we’re working on a new educational initiative, where teachers and informal educators will be able to take back to their classroom their very own piece of SDSS history – an actual SDSS plate which was used to map a small patch of the night sky.

We have been developing a “Plate packet” to distribute to teachers and educators. This packet contains an SDSS plate, along with a custom made poster showing the SDSS image of the region of sky the plate was designed for, as well as some selected educational materials, and links to specially designed activities on SDSS Voyages.

Certificate handed out with each plate.

Certificate handed out with each plate.

On Saturday 30th May 2015, SDSS Members from the University of Washington handed out the first plates to a group of  teachers representing high schools from around the western Washington, USA. These teachers spent the day at the in Seattle discussing ideas for using the plates in their classrooms, as well as getting a tour of the machine shop, where all the SDSS plates are manufactured.

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“Hard at Work”: SDSS Member Oliver Fraser (pink shirt) shows some educators how to find the data from their plates and use it for classroom investigations. A plate poster can be seen on the board in back. Credit: Danielle Skinner

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“Yay Plates!”: some happy educators (and SDSS Member, Danielle Skinner in black) excited to be taking their very own SDSS plates back to their schools. Credit: Oliver Fraser.

The University of Washington is already planning more such workshops, and we look forward to expanding this program to other SDSS Member Institutions.


If you’re a teacher or educator reading this and interested to know how you can get your own SDSS plate, please contact the outreach representative at your nearest SDSS Institution, or email outreach ‘at’ sdss.org for assistance doing that. SDSS members interested in getting involved in this programme should join the EPO mailing list (details on the password protected collaboration wiki). 

David Schlegel Wins an Ernest Lawrence Award

Prof. David Schlegel of Lawrence Berkeley National Laboratory, the PI of the BOSS part of SDSS-III and a long time contributor to all areas of the Sloan Digital Sky Surveys was announced yesterday as one of the winners of the E.O. Lawrence Award.

David Schelegel, PI of BOSS, shows off a plug plate. Image credit: LBL

David Schelegel, PI of BOSS, shows off a plug plate. Image credit: LBL

The Ernest Orlando Lawrence Award was established in 1959 in honor of Ernest Lawrence, who invented the cyclotron (for which he won 1939 Nobel Laureate in physics). The Lawrence Award honors U.S. scientists and engineers, at mid-career, for exceptional contributions in research and development supporting the Department of Energy and its mission to advance the national, economic and energy security of the United States.

The citation for David’s award (for the High Energy Physics Category of the award) reads:

Honored for his exceptional leadership of major projects making the largest two-dimensional and three-dimensional maps of the universe, which have been used to map the expansion rate of the Universe to 10 billion light years and beyond. His fundamental technical contributions to high precision measurements of the expansion history of the Universe, and his massive galaxy redshift surveys to detect baryon acoustic oscillations, has helped ascertain the nature of Dark Energy, test General Relativity, and positively impact fundamental understanding of matter and energy in the universe.  These efforts have made precision cosmology one of the most important new tools of high-energy physics.

All of us at SDSS are delighted to wish David Schlegel many congratulations for this honor.

The SDSS Reverberation Mapping Project

The below post was contributed by Dr. Catherine Grier, a postdoctoral researcher at Penn State University (formerly a graduate student from Ohio State University, and the Director of the OSU Planetarium) who has led a recent paper based on results from the SDSS Reverberation Mapping Project (accepted for publication in the Astrophysical Journal; the full text is available at: arXiv:1503.030706 Screen Shot 2015-05-21 at 17.16.00 Supermassive black holes (SMBHs) are present in all massive galaxies and are thought to affect the formation and development of the galaxies themselves. Because of this, understanding SMBHs is important in understanding how galaxies are formed and evolve. Observations of quasars are key to understanding SMBHs and how they affect their host galaxies: Quasars are enormously powerful, observable at great distances, and can potentially regulate the growth of their galaxies through their winds, or outflows. We learn about these winds by observing broad absorption line features (BALs; see the diagram below) in quasar spectra that are created by high-speed winds launched from the quasar accretion disk. These winds are made of gas that blocks the light from the quasar and show up as BALs in the spectra of quasars.

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The CIV region of our target showing the CIV Broad Absorption Line (BAL) features investigated in our study.

These absorption features change throughout time, both in strength and in shape. Under the right conditions, we can use the details of the variability to learn about the density of the absorbing gas and the distance of the gas from the SMBH. This information can sometimes be used to determine if the outflow is powerful enough to affect the star formation in their host galaxy. Previous studies have found that BALs are variable on timescales of several years all the way down to timescales of 8-10 days; however, until now, no studies have reported variability on timescales shorter than 8-10 days. In our recent work, we report on very short-timescale (~1 day) BAL variability observed in a SDSS quasar. The spectra used in our study were taken as a part of the SDSS Reverberation Mapping (SDSS-RM) project using the BOSS spectrograph. We monitored 850 quasars with the BOSS spectrograph from January 2, 2014 through July 3, 2014, resulting in 32 observations over this period. The main goal of the SDSS-RM program is the investigation of the broad emission line regions of quasars, but the targets include a number of quasars hosting BALs and can be used for BAL studies too. During our observing campaign, the equivalent width, or strength, of the highest-velocity CIV BAL feature (see above diagram) changed by over a factor of 2. We did not observe similar variations in either the CIV broad emission line or the overall brightness of the quasar, and the shape of the BAL feature stayed roughly the same during the entire campaign. We observed significant changes in the strength of the BAL on timescales as low as 1.20 days in the quasar rest frame (see the graphs below). This is the shortest time frame ever reported over which significant variability in a BAL trough has been observed.

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Four different pairs of spectra between which the CIV BAL trough varies significantly.

The most likely cause of the variability is a change in the amount of ionized gas in the outflow. This could be caused by changes in the brightness of the quasar or the amount of energy reaching the absorbing gas for various other reasons. With our observations, we are unable to determine whether this outflow contributes significantly to feedback to the host galaxy, but we do not rule out the possibility. The key to observing this short-term variability was the high cadence of the SDSS-RM campaign, which allowed us to search for BAL variability on shorter timescales than previous studies. This program is still ongoing; we expect to receive more spectra of this target over the next few years with the eBOSS spectrograph, which could shed further light on this topic. The variability properties of this target are similar to those found in other quasars, suggesting that this short-term variability may be common. Further high-cadence spectroscopic campaigns targeting BAL quasars would allow us to learn more about BAL variability in quasars and better understand the possible contributions of BALs to feedback to their host galaxies.

Job Posting: University of Washington Machine Shop Manager

The University of Washington Physics Instrument Shop is looking for a new shop manager.  This is the machine shop which builds the SDSS plug plates, fiber systems, and a number of our other instrumentation and telescope equipment for SDSS, APO 3.5 m, and soon LCO. This shop is a key part of SDSS operations.

Position Description

The Instrument Shop Manager is responsible for the daily operations of a 5 FTE research and development machine shop with an $850,000 annual budget.  The Instrument Shop provides clients (primarily scientists) with both one-of-a-kind and production instruments.  The manager is solely responsible for assessing each client’s request, estimating the amount of time and effort to complete the job, assigning the job to the staff persons whose abilities and experience best fit the request and scheduling the job.  The Manager is the line supervisor for 5 FTE – selecting, hiring, evaluating and disciplining employees as necessary.   The Manager ensures that the proper tooling and materials are on hand for each job, that machines are maintained and repaired and that the workplace is safe. The Manager works closely with faculty, staff and students on their research projects.  Many experiments involve instruments that are not available ‘off the shelf’ and are custom designed for each particular experiment or project.  Faculty, staff and students depend upon the Manager to review their ideas and ensure that the devices are buildable and suggest modifications that may result in a better instrument or make it easier to produce.

Link to the job posting. 

You can get an idea of what goes on in this shop in this video of SDSS plate production

How SDSS uses light to see dark matter in galaxies

Some of the most beautiful pictures taken by telescopes are those of galaxies. Containing billions of stars, they come in many shapes and sizes. We can study the stellar structures in galaxies from telescope images to learn more about the ways that galaxies form and evolve. We also can look at gas and dust features in galaxies, and the role that these play in the formation of new stars.

Elliptical galaxy NGC 4636 (left) and spiral galaxy M81 (right), as seen by the Sloan Telescope. The telescope captures the light of the stars, and in M81 we can also see some dust in the spiral arms. Both galaxies reside in large, invisible, dark matter haloes.

Elliptical galaxy NGC 4636 (left) and spiral galaxy M81 (right), as seen by the Sloan Telescope. The telescope captures the light of the stars, and in M81 we can also see some dust in the spiral arms. Both galaxies reside in large, invisible, dark matter haloes.

Yet, the largest and most massive component of a galaxy, the dark matter halo, is truly invisible. Dark matter is not made out of ‘normal material’ or baryons, which are the building blocks of stars, planets and all other matter surrounding us. Instead, dark matter is thought to be an exotic particle that does not emit or absorb any light: it does not interact with the electromagnetic force like normal matter. So how do we then know that the dark matter is there?

The answer lies in the light that we observe from the stars and the gas in galaxies. With images we capture the presence of light, but with spectrographs we unravel the light into different colours or wavelengths. The resulting galaxy spectra show us how the stars are moving around in the galaxy. In most galaxies, the stars will rotate around the centre of the galaxy, and this rotational velocity can be seen in the spectrum by a shift in the stellar absorption lines. This shift results from the Doppler Effect, which causes the lines of stars that move away from us to shift towards the red part of the spectrum, while the lines of stars that are moving towards us shift to the blue part of the spectrum. This way, we can find out how fast the stars in a galaxy are rotating around the galaxy centre. But there is more information in the spectrum: the lines are not infinitely thin, but are slightly broadened. This broadening is called ‘velocity dispersion’ and is caused by the additional random motions of the stars. With the new Sloan Survey, MaNGA, we are measuring the rotational and random motions of the stars in 10,000 galaxies. And because MaNGA is an integral-field spectrograph, we can map these motions not only in the very centre of the galaxies, but also in their outskirts, as shown below.

MaNGA is an integral-field spectrograph, capturing spectra at multiple points in the same galaxy with a fiber bundle. The bottom right illustrates how each fiber will observe a different section of the galaxy. The top right shows data gathered by two fibers observing two different part of the galaxy, showing how the spectrum of the central regions differs dramatically from outer regions. From these spectra, we measure the rotational and random motions of stars, to deduce how much dark matter is present in the galaxy. Image Credit: Dana Berry / SkyWorks Digital Inc., David Law, and the SDSS collaboration

How do these velocity and dispersion maps help us to find the dark matter? The answer is gravity. The stars are moving around in a galaxy under the influence of gravity: the more matter (mass) there is in the galaxy, the faster the stars are moving. Now that we have measured the movements of the stars in the galaxies, we can deduce how much matter is needed to have the stars move around with those measured velocities. And we can compare that gravitational mass with the luminous mass in the galaxy (the stars, gas and dust). For all galaxies studied so far, the gravitational mass is much larger than the luminous mass: hence the need for dark matter.

Example of a galaxy observed with MaNGA. Left is the image of the galaxy, showing the stellar light. The middle image is the rotational velocity field of the galaxy: the red part of the galaxy is moving away from us with 254 km/s, and the blue part of the galaxy is moving towards us with the same velocity. The green axis down the middle is the rotation axis. The right image shows the random motions of the stars: these are higher in the centre (red: 257 km/s) than in the outskirts of the galaxy (blue: 94 km/s). Figure taken from Bundy et al. 2015.

Example of a galaxy observed with MaNGA. Left is the image of the galaxy, showing the stellar light. The middle image is the rotational velocity field of the galaxy: the red part of the galaxy is moving away from us with 254 km/s, and the blue part of the galaxy is moving towards us with the same velocity. The green axis down the middle is the rotation axis. The right image shows the random motions of the stars: these are higher in the centre (red: 257 km/s) than in the outskirts of the galaxy (blue: 94 km/s). Figure taken from Bundy et al. 2015.

Sophisticated mass or dynamical models of the galaxies, based on the observed velocity and dispersion maps, tell us how the luminous and dark matter are distributed in the galaxy, and what the properties (mass, size, concentration) of the dark haloes are. Comparing these mass models with predictions from galaxy formation theories will help us forward in our quest to understand galaxies, and the dark haloes that surround them. But it all starts with capturing the stellar light of galaxies in spectrographs, to map the invisible.


This post was written by Dr. Anne-Marie Weijmans (St Andrews) and is part of the SDSS Celebration of the International Year of Light 2015, in which we aim to post an article a month about how SDSS uses light in our mission to study the Universe.

Tweep of the Week: Sarah Jane Schmidt

In charge of the SDSS Twitter account for this week is Dr. Sarah Jane Schmidt, the Columbus Prize Postdoctoral Fellow in the Department of Astronomy at The Ohio State University

Dr. Sarah Jane Schmidt

Dr. Sarah Jane Schmidt

Dr. Schmidt studies the lowest mass and most numerous types of stars in our Galaxy – the M and L dwarfs. These types of cool stars have strong magnetic fields on their surfaces which results in special kinds of extra light from the stars, including dramatic flare events, which Dr. Schmidt works to observe and understand.

Within the SDSS collaboration, Dr. Schmidt has worked or is working on observing cool stars using spectroscopy from several different surveys:

1. A study of ultracool dwarfs with data from a BOSS (Baryon Oscillation Spectroscopic Survey) ancillary project

2. A TDSS (Time Domain Spectroscopic Survey) project looking at long timescale magnetic field variations on late-M and early-L dwarfs

3. Studying the colors of late-K and early-M dwarfs with measurements of temperature and metallicity from spectroscopic observations taken for the APOGEE survey.

This can all be summarised as spectroscopy of the lowest mass stars there are, and Sarah is most interested in using these to constrain the stars ages and how this relates to their magnetic activity.

We hope you’ll join the conversation with Sarah and other SDSS scientists on twitter this week so we can all learn more about the magnetic fields of the smallest stars in the Universe.

SDSS Data Lead to Discovery of 12 Billion Solar Mass Black Hole in Young Universe

A paper appearing in Nature today (Xue-Bing Wu et al. 2015, Nature, Feb 25) presents the most massive black hole discovered to date when the Universe, was less than a billion years old – just one-fifteenth of its current age.

A new method to select high-redshift quasars using SDSS observations combined with data from the WISE satellite has resulted in the discovery of new group of quasars at the far reaches of the universe, with redshifts greater than z = 5. One of these quasars, named SDSS J0100+2802, holds a super-massive black hole at a redshift of 6.3 when the Universe was only 900 million years old.

This black hole is estimated to have a mass 12 billion times that of our Sun. The existence of such a massive black hole at such an early stage in the Universe poses a deep mystery whose resolution will improve our understanding of how galaxies form.

For more information, see the following links:

A graph of quasar luminosity vs. mass, with SDSS J0100+2802 marked

The newly discovered quasar SDSS J0100+2802 is shown by the large red dot in the graph above. The graph shows that SDSS J0100+2802 has most massive black hole and the highest luminosity among all known distant quasars. The background photo, provided by Yunnan Observatory, shows the dome of the 2.4-meter telescope and the sky above it. (Image: Zhaoyu Li/Shanghai Observatory)

How SDSS uses light to study the darkest objects in the Universe

Black holes are intriguing objects. A black hole is a phenomenon whose gravity is so strong that not even light, the fastest traveller in the Universe, can escape from its influence. Once thought mere oddities due to their extreme properties, today, black holes are found to be vital in the formation and lives of galaxies, including our own Milky Way.

But how do we know black holes exist if we can’t see them? Well, even if we can’t see a black hole directly we can observe their influence and indeed the energy and light emitted as gas, dust and stars fall into a black hole; that is, we can see black holes when they are actively “eating” material.  When the supermassive black hole, which can be up to a billion times more massive than our Sun, at the center of a galaxy starts to eat new material the resulting process is so bright it can be seen out to ~200 billion lightyears away.  Astronomers call the observational result of this process either an active galactic nuclei, or in the most extreme examples a “quasar”. So you might be surprised to find that an object that emits no light can cause the brightest known phenomenon in the Universe!

Quasar

An artist’s rendition of a quasar created by Coleman Krawczyk (ICG Portsmouth).  The image is drawn on a radial log scale with the central black hole 1 AU in size.

The light of quasars is not produced by the black hole itself, but instead it comes from the material, mostly gas, that is falling into the black hole.  Different types of light are produced by this material at different distances outward from the black hole.  Near the surface (or horizon) of the black hole (about the distance of the Earth’s orbit away for supermassive black holes in galaxies) this gas becomes extremely hot and produces X-rays. Stretching out from this to fill a region about the size of our Solar System, a disk of gas shaped like a frisbee is formed.  The inside of this disk is closer to the black hole than the outside, so it rotates faster causing friction within the disk.  This friction causes the gas to heat up and glow, producing light in the optical to ultraviolet part of the spectrum.

From the edge of the gas disk to a distance of about 3 light years (similar to the distance from the Sun to the next closest star), the temperature becomes low enough that particles of “interstellar dust”, made of carbon and silicon, form.  These dust clouds form what is know as the “dusty torus,” a donut shaped ring round the gas disk. Some of the light coming from the gas disk is absorbed by the dust and re-emitted at longer wavelength infrared light. At very large distances from the black hole, some quasars have radio jets coming out along the poles.  As the name suggests, this jets produce light at radio wavelengths cased by electrons being accelerated along a strong magnetic field.  When these jets are present they can be up to ~300 thousand lightyears (~3 times the diameter of our entire galaxy!) in size.

Not only can a black hole produce light, it can create light at all wavelengths from the radio up to the X-ray, and across an area stretching from the size of the Earth’s orbit out to distances larger than the Milky Way.  Therefore, growing black holes, and the regions around them are anything but “black.”

With discoveries from its earliest imaging campaigns, the SDSS extended the study of quasars back to the first billion years after the Big Bang, showing the rapid early growth of black holes and mapping the end stages of the epoch of reionization.

Stacked spectra of more than 46,000 quasars from the SDSS; each spectrum has been converted to a single horizontal line, and they are stacked one above the other with the closest quasars at the bottom and the most distant quasars at the top. Credit: X. Fan and the Sloan Digital Sky Survey.

Stacked spectra of more than 46,000 quasars from the SDSS; each spectrum has been converted to a single horizontal line, and they are stacked one above the other with the closest quasars at the bottom and the most distant quasars at the top.
Credit: X. Fan and the Sloan Digital Sky Survey.

With full quasar samples hundreds of times larger than those that existed before, the SDSS has given us the most accurate descriptions of the growth of black holes over cosmic history.  SDSS spectra show that the properties of quasars have changed remarkably little from the early universe to the present day.

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Growth in the number of known quasars in the largest homogeneous (solid) and heterogeneous (dashed) quasar catalogs as a function of time. The Sloan Digital Sky Survey catalogues started being produced in 2000. Fig. 1 from Richards et al. (2009).

SDSS studies have probed the dark matter environments of quasars through clustering measurements, revealed populations of quasars whose central engines are hidden by obscuring dust, captured changes in quasar spectra that show clouds moving in the gravitational grip of the central black hole, and allowed a comprehensive census of the much fainter accreting black holes (active galactic nuclei, or AGN) in present-day galaxies.
This, our first post for the IYL2015 is a collaboration between Coleman Krawcyzk (ICG Portsmouth); Nic Ross (ROE) with help from Karen Masters (ICG Portsmouth).

This post is part of the SDSS Celebration of the International Year of Light 2015, in which we aim to post an article a month about how SDSS uses light in our mission to study the Universe. 

SDSS Celebrates the International Year of Light 2015

As astronomers, at the Sloan Digital Sky Survey everything we do is based on collecting light from cosmic objects. SDSS is therefore pleased that in 2015 we are celebrating the International Year of Light, and we especially would like to point out the Cosmic Light Theme, supported by the IAU.cosmiclight_color_whitebg

As a small contribution to this celebration, every month in 2015 SDSS will have a special post on here talking about the different ways we use light. Our first post, which will appear before the end of January will be about how we use light to study black holes, something which seems like a contradiction, but has taught us a lot!

This post will be updated to collect all the links as the year progresses:

Joint BOSS+eBOSS Collaboration in Cloudcroft, NM

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SDSS collaboration members gathered around the telescope at an unfortunately beautiful sunset.

The SDSS-III BOSS and SDSS-IV eBOSS are in the middle of a 4-day meeting to discuss the continuing great science coming out of BOSS, looking at the first data from eBOSS, and planning for the bright future of SDSS-IV.  The location is Cloudcroft, New Mexico, which is only 17 miles from the Apache Point Observatory, home of The Sloan Foundation 2.5-meter Telescope, which has been the main telescope for SDSS for the past decade-and-a-half.  This proximity allows for collaboration members to visit the telescope and meet the hardworking mountain staff who keep it all running smoothly.

Cloudcroft has been a central landing point for all of the years of the SDSS survey, and in recognition of this, honorary membership was granted to a certain permanent member of the staff at The Lodge Resort at Cloudcroft:

SDSS_BOSS_eBOSS_Attendee