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Warm H₂ as a probe of massive accretion and feedback through shocks and turbulence across cosmic time

Appleton, Philip N. and Armus, Lee and Boulanger, François and Bradford, Matt and Braine, Jonathan and Bromm, Volker and Capak, Peter and Cluver, Michelle and Cooray, Asantha and Díaz-Santos, Tanio and Egami, Eiichi and Emonts, Bjorn and Guillard, Pierre and Helou, George and Lanz, Lauranne and Madden, Susanne and Medling, Anne and O'Sullivan, Ewan and Ogle, Patrick and Pope, Alexandra and Pineau des Forêts, Guillaume and Shull, J. Michael and Smith, John-David and Togi, Aditya and Xu, C. Kevin (2019) Warm H₂ as a probe of massive accretion and feedback through shocks and turbulence across cosmic time. Astro2020 Science White Paper, . (Unpublished)

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Galaxy formation depends on a complex interplay between gravitational collapse, gas accretion, merging, and feedback processes. Yet, after many decades of investigation, these concepts are poorly understood. This paper presents the argument that warm H₂ can be used as a tool to unlock some of these mysteries. Turbulence, shocks and outflows, driven by star formation, AGN activity or inflows, may prevent the rapid buildup of star formation in galaxies. Central to our understanding of how gas is converted into stars is the process by which gas can dissipate its mechanical energy through turbulence and shocks in order to cool. H₂ lines provide direct quantitative measurements of kinetic energy dissipation in molecular gas in galaxies throughout the Universe. Based on the detection of very powerful H₂ lines from z = 2 galaxies and proto-clusters at the detection limits of Spitzer, we are confident that future far-IR and UV H₂ observations will provide a wealth of new information and insight into galaxy evolution to high-z. Finally, at the very earliest epoch of star and galaxy formation, warm H₂ may also provide a unique glimpse of molecular gas collapse at 7 < z < 12 in massive dark matter (DM) halos on their way to forming the very first galaxies. Such measurements are beyond the reach of existing and planned observatories.

Item Type:Report or Paper (White Paper)
Related URLs:
URLURL TypeDescription Paper
Appleton, Philip N.0000-0002-7607-8766
Armus, Lee0000-0003-3498-2973
Bradford, Matt0000-0001-5261-7094
Capak, Peter0000-0003-3578-6843
Cluver, Michelle0000-0002-9871-6490
Cooray, Asantha0000-0002-3892-0190
Díaz-Santos, Tanio0000-0003-0699-6083
Guillard, Pierre0000-0002-2421-1350
Helou, George0000-0003-3367-3415
Lanz, Lauranne0000-0002-3249-8224
Medling, Anne0000-0001-7421-2944
Ogle, Patrick0000-0002-3471-981X
Pope, Alexandra0000-0001-8592-2706
Smith, John-David0000-0003-1545-5078
Togi, Aditya0000-0001-5042-3421
Xu, C. Kevin0000-0002-1588-6700
Additional Information:Submitted as a science White Paper to the Astronomy and Astrophysics Astro 2020 Decadal Survey call issued by the National Academies of Sciences, Engineering and Medicine (March 11 2019).
Group:Infrared Processing and Analysis Center (IPAC)
Series Name:Astro2020 Science White Paper
Record Number:CaltechAUTHORS:20191217-095259394
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:100325
Deposited By: Tony Diaz
Deposited On:17 Dec 2019 18:10
Last Modified:09 Mar 2020 13:19

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