Starship Asterisk*

NASA's Chandra X-ray Observatory has shed new light on the mystery of why giant elliptical galaxies have few, if any, young stars. This new evidence highlights the important role that supermassive black holes play in the evolution of their host galaxies.

Because star-forming activity in many giant elliptical galaxies has shut down to very low levels, these galaxies mostly house long-lived stars with low masses and red optical colors. Astronomers have therefore called these galaxies "red and dead".

Previously it was thought that these red and dead galaxies do not contain large amounts of cold gas - the fuel for star formation - helping to explain the lack of young stars. However, astronomers have used ESA's Herschel Space Observatory to find surprisingly large amounts of cold gas in some giant elliptical galaxies. In a sample of eight galaxies, six contain large reservoirs of cold gas. This is the first time that astronomers have seen large quantities of cold gas in giant elliptical galaxies that are not located at the center of a massive galaxy cluster. ...

• Monthly Notices of the RAS 439(3) 2291 (2014 Apr 11) DOI: 10.1093/mnras/stu006
  arXiv.org > astro-ph > arXiv:1310.5450 > 21 Oct 2013 (v1), 13 Jan 2014 (v2)