SDSS in the News

Discovery of first binary-binary calls standard model of solar system formation into question

/ Karen Masters / Leave a comment

The below is based on a press release about work by University of Florida astronomy professor Jian Ge making use of SDSS MARVELS data. We congratulate Prof. Ge and his postdoc Dr. Bo Ma on their very interesting result.

The standard picture we have for the formation of solar systems is oversimplified, according to a paper led by University of Florida astronomy professor Jian Ge and his postdoc, Bo Ma. They’ve discovered the first “binary–binary” – two massive companions around one star in a close binary system, one so-called giant planet  and one brown dwarf, or “failed star” The first, called MARVELS-7a, is 12 times the mass of Jupiter, while the second, MARVELS-7b, has 57 times the mass of Jupiter.

Artist’s conception of an extrasolar planetary system (credit: T. Riecken).

Astronomers believe that planets in our solar system formed from a collapsed disk-like gaseous cloud, with our largest planet, Jupiter, buffered from smaller planets by the asteroid belt. In the new binary system, HD 87646, the two giant companions are close to the minimum mass for burning deuterium and hydrogen, meaning that they have accumulated far more dust and gas than what a typical collapsed disk-like gaseous cloud can provide. They were likely formed through another mechanism. The stability of the system despite such massive bodies in close proximity raises new questions about how protoplanetary disks form. The findings will be published in the October issue of the Astronomical Journal.

 

HD 87646’s primary star is 12 percent more massive than our sun, yet is only 22 astronomical units away from its secondary, a star about 10 percent less massive than our sun, roughly the distance between the sun and Uranus in our solar system. An astronomical unit is the mean distance between the center of the Earth and our sun, but in cosmic terms, is a relatively short distance. Within such a short distance, two giant companions are orbiting the primary star at about 0.1 and 1.5 astronomical units away. For such large companion objects to be stable so close together defies our current popular theories on how solar systems form.

 

The planet-hunting Doppler instrument W.M. Keck Exoplanet Tracker, or KeckET, developed by a team led by Ge at the Sloan Digital Sky Survey telescope at Apache Point Observatory in New Mexico, is unusual in that it can simultaneously observe dozens of celestial bodies. Ge says this discovery would not have been possible without a multiple-object Doppler measurement capability such as KeckET to search for a large number of stars to discover a very rare system like this one. The survey of HD 87646 occurred in 2006 during the pilot survey of the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS) of the SDSS-III program, and Ge led the MARVELS survey from 2008 to 2012. It has taken eight years of follow-up data collection through collaboration with over 30 astronomers at seven other telescopes around the world and careful data analysis, much of which was done by Bo Ma, to confirm what Ge calls a “very bizarre” finding.

 

The team will continue to analyze data from the SDSS-III MARVELS survey.

Sources: Jian Ge

jge@astro.ufl.edu, 352-294-1850

Bo Ma

boma@ufl.edu, 352-294-1854

Writer: Rachel Wayne

rwayne86@ufl.edu, 352-294-7210

 

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

/ bsouter / Leave a comment

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)

SDSS in the News (Aug-Nov 2014)

/ bsouter / Leave a comment

Back in mid August I set up a Google alert search on “sloan digital sky surveys”. Here is a summary of 3 months of mentions of SDSS in online news:

August 21st: Discovery of one of the oldest stars in the Universe, SDSS J0018-0939, illustrated with SDSS image of the star:
Space Fellowship.com, IBTimes, KRWG.org

Oldeststar

An optical image of the star SDSS J0018-0939, obtained by the Sloan Digital Sky Survey. This is a low-mass star with a mass about half that of the Sun; the distance to this star is about 1000 light years; its location in the sky is close to the constellation Cetus. (Credit: SDSS/NAOJ)

 

 

Sept 10th, 21st: A report on looking for patterns in the properties of quasars using SDSS spectra:
Arstechnica.com, ScienceCodex.com.

Sept 25th: Discovery of ‘hyper-compact star clusters’ helped by SDSS data: SpartanDaily

Oct 3rd: “Artificial Intelligence Opens a New Window to the Universe”, Huffington Post.

“Robotic telescopes constantly collect astronomical data and generate enormous astronomical databases. For instance, Sloan Digital Sky Survey (SDSS) has imaged over 400 million galaxies since it saw first light in 2000. ”

So obviously this mentions SDSS, but implies it’s a robotic telescope!  Our team of observers, plate pluggers, and drillers, and the hundreds of other people who work hard to keep SDSS observing might object to this….

D120330_07_PlugCrewAfter100kFibers.500

In March 2012, BOSS observed 103,000 spectra, each of which was routed through a fiber-optic cable that was plugged by hand. The industrious APO plugging crew is pictured here showing the deleterious effects of having placed more than 2,000 fibers/finger in a month. But don’t worry, they recovered have continued to plug every fibre optic by hand during the day at APO – they might even be doing it as you read this! (Image Credit: Dan Long, APO).

Amazing that our observing process is so smooth that to outsiders it appears to be like a robot! Stay tuned for a newly planned “The SDSS Telescope is not Robotic” article. 🙂

Oct 8th:
Opinion: “Why More Inventions Don’t Win Nobel Prizes, and Why That’s a Good Thing”, National Geographic.

Cites SDSS as one of the reasons it was right that the invention of the CCD got the 2009 Nobel Prize in Physics because of the realms of discovery it opened up:

“The world could get along well without camera cell phones. What’s exciting about CCDs, whose inventors won the 2009 physics prize, is their use in the Hubble Space Telescope and the Sloan Digital Sky Survey.”

Oct 10th: “New Study of Spiral Arms”, Phys.org

Authors use a sample of 50 non-barred and two armed spiral galaxies selected from SDSS and measure spiral arm pitch angles, finding most are only approximately log spiral, typically having decreasing pitch angle as radius increased. Link to paper.

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NGC 3338, a non-barred two armed spiral in the study. Credit: SDSS.

 

 

Oct 17th: “A 3D Map of true Adolescent Universe”, SpatialNews, RDMag, Nature World News.
Discussion of plans for new redshift surveys mentions SDSS as “The first big 3D map of the universe”:

Oct 22nd: “Chandra Data Archive Comes to Life”, RedOrbit

Report on release of images from the Chandra archive, which us SDSS images (among many others) to make nice multi wavelength images, like the below one of NGC 4736.

NGC 4736 (also known as Messier 94) is a spiral galaxy that is unusual because it has two ring structures. This galaxy is classified as containing a “low ionization nuclear emission region,” or LINER, in its center, which produces radiation from specific elements such as oxygen and nitrogen. Chandra observations (gold) of NGC 4736, seen in this composite image with infrared data from Spitzer (red) and optical data from Hubble and the Sloan Digital Sky Survey (blue), suggest that the X-ray emission comes from a recent burst of star formation. Part of the evidence comes from the large number of point sources near the center of the galaxy, showing that strong star formation has occurred. In other galaxies, evidence points to supermassive black holes being responsible for LINER properties. Chandra’s result on NGC 4736 shows LINERs may represent more than one physical phenomenon. (X-ray: NASA/CXC/Universita di Bologna/S.Pellegrini et al, IR: NASA/JPL-Caltech; Optical: SDSS & NASA/STScI)

NGC 4736 (also known as Messier 94) is a spiral galaxy that is unusual because it has two ring structures. This galaxy is classified as containing a “low ionization nuclear emission region,” or LINER, in its center, which produces radiation from specific elements such as oxygen and nitrogen. Chandra observations (gold) of NGC 4736, seen in this composite image with infrared data from Spitzer (red) and optical data from Hubble and the Sloan Digital Sky Survey (blue), suggest that the X-ray emission comes from a recent burst of star formation. Part of the evidence comes from the large number of point sources near the center of the galaxy, showing that strong star formation has occurred. In other galaxies, evidence points to supermassive black holes being responsible for LINER properties. Chandra’s result on NGC 4736 shows LINERs may represent more than one physical phenomenon. (X-ray: NASA/CXC/Universita di Bologna/S.Pellegrini et al, IR: NASA/JPL-Caltech; Optical: SDSS & NASA/STScI)

 

Oct 27th: “Nothing Can Escape Black Holes – this Lucky Star Did”, TechTimes
Study which revealed a star loosing a portion of its mass to a black hole used some SDSS data.

Oct 31st: “Universe May Face a Darker Future”, PhysOrg, TechTimes, Digital Journal.

Cosmologists use galaxies observed by the Sloan Digital Sky Survey to study the nature of dark energy and find support for a scenario in which dark matter decays into dark energy.

Nov 4th: “The Rise of Astrostatistics”, Symmetry Magazine.

“I believe the large surveys shocked astronomers with how much data there is,” Hilbe says. “The Sloan Digital Sky Survey [one of the first automated and digitized comprehensive astronomical sky surveys] told them they needed statistics.”

Notice another mention of SDSS applying the process is automated, which we addressed above (thanks again to our wonderful observing team). Apparently this idea is fairly ubiquitous in the media….

astrostatistics_header_Artwork by Sandbox Studio, Chicago with Kimberly Boustead

Neat illustration of astrostatistic: Artwork by Sandbox Studio, Chicago with Kimberly Boustead for Symmetry Magazine article.

 

 

Nov 6th:  “Never has so much data been collected so fast” Edmonton Journal.
Article about big data in astronomy begins:

“When the Sloan Digital Sky Survey began in 2000, its telescope in New Mexico collected more data in its first few weeks than had been amassed in the entire history of astronomy.”

Nov 7th: “Exploring the Murky Centers of Dust Shrouded Galaxies”, PhysOrg, Science World Report.

Articles use an SDSS image to illustrate the LMT pointing at galaxy 5MUSES-229, one of the dusty galaxies in the study which was used to study the relative contributions of AGN and star formation in the heating of dust.

usandmexican

The LMT pointed at 5MUSES-229, a galaxy approximately one billion light years distant from the Milky Way. With the LMT, astronomers are able to observe the carbon monoxide emission from this galaxy. Credit: James Lowenthal, the background image showing the galaxy is from SDSS.

 

Nov 14th: “How Young, Massive, Compact Galaxies Evolve into Their Red, Dead Elders”, Science World Report.

Report on study using a sample of poststarburst galaxies identified in SDSS and followed up with HST and Chandra.

 

 

 

To set up your own alert, visit news.google.com, search on “sloan digital sky survey” and click “Create alert” which can be found at the bottom on the page.

 

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