Space

August 28, 2014

NASA telescopes uncover early construction of giant galaxy

Artist impression of a firestorm of star birth deep inside core of young, growing elliptical galaxy.

Astronomers have for the first time caught a glimpse of the earliest stages of massive galaxy construction. The building site, dubbed Sparky, is a dense galactic core blazing with the light of millions of newborn stars that are forming at a ferocious rate.

The discovery was made possible through combined observations from NASA’s Hubble and Spitzer space telescopes, the W.M. Keck Observatory in Mauna Kea, Hawaii, and the European Space Agency’s Herschel space observatory, in which NASA plays an important role.

A fully developed elliptical galaxy is a gas-deficient gathering of ancient stars theorized to develop from the inside out, with a compact core marking its beginnings. Because the galactic core is so far away, the light of the forming galaxy that is observable from Earth was actually created 11 billion years ago, just 3 billion years after the Big Bang.

Although only a fraction of the size of the Milky Way, the tiny powerhouse galactic core already contains about twice as many stars as our own galaxy, all crammed into a region only 6,000 light-years across. The Milky Way is about 100,000 light-years across.

We really hadn’t seen a formation process that could create things that are this dense, explained Erica Nelson of Yale University in New Haven, Connecticut, lead author of the study. We suspect that this core-formation process is a phenomenon unique to the early universe because the early universe, as a whole, was more compact. Today, the universe is so diffuse that it cannot create such objects anymore.

In addition to determining the galaxy’s size from the Hubble images, the team dug into archival far-infrared images from Spitzer and Herschel. This allowed them to see how fast the galaxy core is creating stars. Sparky produced roughly 300 stars per year, compared to the 10 stars per year produced by our Milky Way.

They’re very extreme environments, Nelson said. It’s like a medieval cauldron forging stars. There’s a lot of turbulence, and it’s bubbling. If you were in there, the night sky would be bright with young stars, and there would be a lot of dust, gas, and remnants of exploding stars. To actually see this happening is fascinating.

Astronomers theorize that this frenzied star birth was sparked by a torrent of gas flowing into the galaxy’s core while it formed deep inside a gravitational well of dark matter, invisible cosmic material that acts as the scaffolding of the universe for galaxy construction.

Observations indicate that the galaxy had been furiously making stars for more than a billion years. It is likely that this frenzy eventually will slow to a stop, and that over the next 10 billion years other smaller galaxies may merge with Sparky, causing it to expand and become a mammoth, sedate elliptical galaxy.

I think our discovery settles the question of whether this mode of building galaxies actually happened or not, said team-member Pieter van Dokkum of Yale University. The question now is, how often did this occur? We suspect there are other galaxies like this that are even fainter in near-infrared wavelengths. We think they’ll be brighter at longer wavelengths, and so it will really be up to future infrared telescopes such as NASA’s James Webb Space Telescope to find more of these objects.

The paper appears in the Aug. 27 issue of the journal Nature.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colo. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines January 28, 2015

News: Panel will propose new military retirement system - The long-awaited report on military compensation set to drop Thursday will propose fundamental changes to military retirement and health care benefits, according to several people familiar with the report. Source: DOD to request $585 billion for fiscal 2016 - The Department of Defense is preparing to submit a...
 
 

News Briefs January 28, 2015

Defense contractor to pay $2 million to settle claims A Northern California defense contractor will pay the federal government $2 million to settle claims about its manufacturing of parts for remote-controlled aircraft. The U.S. Attorney’s Office in Sacramento says Sacramento-based Composite Engineering Inc. agreed to pay the money to end allegations that it artificially inflated...
 
 
Navy photograph

USS Roosevelt marks 200,000 trap

Navy photograph An F/A-18F Super Hornet flown by Capt. Daniel Grieco, commanding officer of the aircraft carrier USS Theodore Roosevelt (CVN 71), and Capt. Benjamin Hewlett, deputy commander of Carrier Air Wing (CVW) 1, complet...
 

 
Navy photograph by PO1 William Larned

USS California returns from maiden deployment

Navy photograph by PO1 William Larned The Virginia-class attack submarine USS California (SSN 781) returns from its maiden deployment to its homeport at Naval Submarine Base New London. Under the command of Cmdr. Shawn Huey, Ca...
 
 
Army photograph

Army proves new watercraft capabilities

Army photograph Marine Corps assets are loaded onto the USNS Sgt. Matej Kocak (T-AK 3005), from an U.S. Army Landing Craft Utility, or LCU, USAV Port Hudson during port operations, at White Beach Naval Base, Jan. 22, 2015. Sold...
 
 

Orbital stockholders approve merger with ATK’s aerospace, defense groups

Orbital Sciences Corporation announced Jan. 27 that at a special meeting, the company’s stockholders voted overwhelmingly to approve the proposed merger with the Aerospace and Defense Groups of Alliant Techsystems Inc., pursuant to the definitive transaction agreement dated April 28, 2014. Approximately 99 percent of the votes cast at the special meeting voted in favor...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>