Published in "Gas Accretion onto Galaxies", Astrophysics and Space Science Library, Volume 430. ISBN 978-3-319-52511-2. Springer International Publishing AG, 2017, p. 355.
https://arxiv.org/abs/1612.00740

For a PDF version of the article, click here.

GAS ACCRETION AND STAR-FORMATION RATES WITH IFUS AND BACKGROUND QUASARS

Nicolas F. Bouché


IRAP, 9 Av. Colonel Roche, F-31400 Toulouse


Abstract: Star forming galaxies (SFGs) are forming stars at a regular pace, forming the so-called main sequence (MS). However, all studies of their gas content show that their gas reservoir ought to be depleted in 0.5-2 Gyr. Thus, SFGs are thought to be fed by the continuous accretion of intergalactic gas in order to sustain their star-formation activity. However, direct observational evidence for this accretion phenomenon has been elusive. Theoretically, the accreted gas coming from the intergalactic medium is expected to orbit about the halo, delivering not just fuel for star-formation but also angular momentum to the galaxy. This accreting material is thus expected to form a gaseous structure that should be co-rotating with the host once at r < 0.3 Rvir or r < 10−30 kpc. Because of the rough alignment between the star-forming disk and this extended gaseous structure, the accreting material can be most easily detected with the combination of background quasars and integral field units (IFUs). In this chapter, accretion studies using this technique are reviewed.


Table of Contents

GAS ACCRETION IN THE CONTEXT OF GALAXY EVOLUTION

DETECTING GAS ACCRETION
Observational and Technological breakthroughs
Measuring the Gas Accretion Rate

GAS ACCRETION FROM IFU SURVEYS
Case Study 1: HE2243 at z = 2.32
Case Study 2: J1422 at z = 0.91
Metallicity aspects
Case Study 3: H I selection
Case Study 3: H I selection

FUTURE PERSPECTIVES

REFERENCES

Next