University of California, Riverside | W.M. Keck Observatory | 2017 Jul 20
The international SpARCS collaboration based at UC Riverside has made the best measurement yet of the amount of fuel available to form stars in clusters of galaxies located in the early universe.
[c][attachment=0]Tadpole-Galaxy[1].jpg[/attachment][/c][hr][/hr]The international Spitzer Adaptation of the Red-sequence Cluster Survey (SpARCS) collaboration based at the University of California, Riverside, has combined observations from several of the world’s most powerful telescopes to carry out one of the largest studies yet of molecular gas -- the raw material which fuels star formation throughout the universe -- in three of the most distant clusters of galaxies ever found, detected as they appeared when the universe was only four billion years old. ...
Clusters are rare regions of the universe consisting of tight groups of hundreds of galaxies containing trillions of stars, as well as hot gas and mysterious dark matter. First, the research team used spectroscopic observations from the W. M. Keck Observatory on Mauna Kea, Hawai’i, and the Very Large Telescope in Chile that confirmed 11 galaxies were star-forming members of the three massive clusters. Next, the researchers took images through multiple filters from NASA’s Hubble Space Telescope, which revealed a surprising diversity in the galaxies’ appearance, with some galaxies having already formed large disks with spiral arms.
One of the telescopes the SpARCS scientists used is the extremely sensitive Atacama Large Millimeter Array (ALMA) telescope capable of directly detecting radio waves emitted from the molecular gas found in galaxies in the early universe. ALMA observations allowed the scientists to determine the amount of molecular gas in each galaxy, and provided the best measurement yet of how much fuel was available to form stars. ...
ALMA Observations of Gas-Rich Galaxies in z ~ 1.6 Galaxy Clusters:
Evidence for Higher Gas Fractions in High-Density Environments - A.G. Noble et al
- Astrophysical Journal Letters 842(2):L21 (2017 Jun 20) DOI: 10.3847/2041-8213/aa77f3
arXiv.org > astro-ph > arXiv:1705.03062 > 08 May 2017 (v1), 22 Jun 2017 (v2)