by James Allison (CASS)

We used the IRAM 30m and Arecibo 300m telescopes to measure the amount of molecular and atomic gas, respectively, in a sample of large galaxies that showed evidence of having recently swallowed up a nearby dwarf galaxy. Surprisingly we found that the rate at which stars form is not what we expect, given the amount of gas measured, suggesting that the very act of merging may suppress star formation. – Reference: Davis, Rowlands, Allison, Shabala, Ting, Lagos, Kaviraj, Bourne, Dunne, Eales, Ivison, Maddox, Smith, Smith, & Temi 2015, MNRAS 449, 3503 .

Credits: IRAM-30m telescope (bottom left): “Copyright IRAM”, Arecibo telescope (top left): “Courtesy of the NAIC – Arecibo Observatory, a facility of the NSF”, SDSS galaxy image (right).