National Radio Astronomy Observatory | 2016 Jun 02
Astronomers have used new capabilities of the National Science Foundation's Karl G. Jansky Very Large Array (VLA) to open a whole new realm of research into how galaxies evolve and interact with their surroundings over cosmic time. They detected the faint radio emission from atomic hydrogen, the most abundant element in the Universe, in a galaxy nearly 5 billion light-years from Earth. ...
The scientists detected the radio "fingerprint" of hydrogen in a galaxy called COSMOS J100054. The discovery came from the first 178 hours of observation in a program called the COSMOS HI Large Extragalactic Survey, or CHILES, led by Jacqueline van Gorkom of Columbia University. The CHILES project eventually will use more than 1,000 hours of VLA observing time. The detection was made possible by the improved capabilities of the VLA provided by a 10-year upgrade project completed in 2012. ...
Hydrogen gas is the raw material for making stars. Throughout their lives, galaxies draw in the gas, which eventually is incorporated into stars. In furious bursts of star formation, stellar winds and supernova explosions can blow gas out of the galaxy and rob it of the material needed for further star formation.
In order to understand how these processes develop, astronomers need images of the gas in and near galaxies of different ages. Until now, technical limitations of radio telescopes prevented them from detecting atomic hydrogen emission at the distances needed to see the gas in galaxies distant enough to provide the required "lookback time." The CHILES project will achieve this to distances out to about 6 billion light-years. ...
Highest Redshift Image of Neutral Hydrogen in Emission:
A CHILES Detection of a Starbursting Galaxy at z=0.376 - Ximena Fernández et al
- Astrophysical Journal Letters 824(1):L1 (2016 Jun 10) DOI: 10.3847/2041-8205/824/1/L1
arXiv.org > astro-ph > arXiv:1606.00013 > 31 May 2016