Feeding and feedback – molecular gas in AGNs and starbursts

04/09/2019
S. Aalto (Chalmers University, Sweden)
Bat 713, salle de séminaires Galilée
(Piano)
09/04/2019
from 10:00 to 11:00

Cold gas plays a central role in feeding and regulating star formation and growth of supermassive black holes (SMBH) in galaxy nuclei. Particularly powerful activity occurs when interactions of gas-rich galaxies funnel large amounts of gas and dust into nuclei of luminous and ultra luminous infrared galaxies (LIRGs/ULIRGs). These dusty objects are of key importance to galaxy mass assembly over cosmic time.

It is also increasingly clear that feedback from star formation and AGNs is fundamental to regulating the evolution of galaxies in the nearby Universe as well as at earlier epochs. Mechanical feedback occurs in the form of winds, turbulence, supernova bubbles and superbubbles, AGN jets and backflows. There is mounting evidence that massive amount of cold molecular gas is being expelled from galaxy nuclei and starburst regions by the feedback process. With the advent of ALMA and the NOEMA telescopes we can now study the structure, physical conditions and chemistry of the cold flows and the dusty nuclei at unprecedented sensitivity and resolution.

I will focus on recent ALMA and NOEMA studies of AGN and starburst outflows from dusty galaxies. I will, for example, present recent ALMA studies with resolutions of 20 milli arcseconds (2 – 7 pc) of the launch regions of molecular outflows and jets in the nearby LIRGs NGC1377 and IC860. These outflows are different from each-other where NGC1377 shows a 150 pc scale radio-quiet molecular jet (that appears to be precessing) while the IC860 flow is exceedingly compact and dense and appears to be in a young phase. I will also discuss observational methods that reach behind the curtain of dust in the most obscured centers of U/LIRGs , allowing us to undertake new studies of heretofore hidden, rapid evolutionary phases of galaxy nuclei.

Local contact, organization: V. Lebouteiller, M. Galametz

SAP