Bjorn Emonts

Bjorn Emonts Colloquium: Cold molecular gas in high-z proto-cluster radio galaxies

Marsfield Lecture Theatre

Abstract

Title:
Cold molecular gas in high-z proto-cluster radio galaxies: ATCA's strength in the ALMA era

Abstract:
I will present ATCA result from a survey for cold molecular CO(1-0) gas in proto-cluster radio galaxies at z~2. In various systems we detect large amounts of very widespread molecular gas, which reveal interesting physical processes in the evolution of these distant galaxies. In several cases, we find localised CO(1-0) emission far away from the host galaxy, just beyond the tip of the radio jet. This is suggests that jet-induced feedback triggers the formation of molecular gas out to ~100 kpc in the halo environment. I will also show the intriguing case of the Spiderweb Galaxy, where CO(1-0) is spread across a ~70 kpc reservoir in the center of a proto-cluster. The cold molecular gas appears to be located in between the proto-galaxies, where it fuels in-situ star formation across the IGM. Its low velocity dispersion suggests that the gas has been deposited through long-sought cold accretion processes. During the talk, I will compare our ATCA results with recent studies that we did with ALMA and the VLA, and show that the ATCA is an excellent complement to these facilities. In particular its low-surface-brightness sensitivity and ability to target the lowest CO transitions allow us to perform unique science with the ATCA millimetre system.