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A Newly Forming Cold Flow Protogalactic Disk, a Signature of Cold Accretion from the Cosmic Web

Martin, D. Christopher and Matuszewski, Mateusz and Morrissey, Patrick and Neill, James D. and Moore, Anna and Steidel, Charles C. and Trainor, Ryan (2016) A Newly Forming Cold Flow Protogalactic Disk, a Signature of Cold Accretion from the Cosmic Web. Astrophysical Journal Letters, 824 (1). Art. No. L5. ISSN 2041-8205.

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How galaxies form from, and are fueled by, gas from the intergalactic medium (IGM) remains one of the major unsolved problems in galaxy formation. While the classical Cold Dark Matter paradigm posits galaxies forming from cooling virialized gas, recent theory and numerical simulations have highlighted the importance of cold accretion flows—relatively cool (T ~ few × 104 K) unshocked gas streaming along filaments into dark matter halos, including hot, massive, high-redshift halos. These flows are thought to deposit gas and angular momentum into the circumgalactic medium resulting in disk- or ring-like structures, eventually coalescing into galaxies forming at filamentary intersections. We earlier reported a bright, Lyα emitting filament near the QSO HS1549+19 at redshift z = 2.843 discovered with the Palomar Cosmic Web Imager. We now report that the bright part of this filament is an enormous (R > 100 kpc) rotating structure of hydrogen gas with a disk-like velocity profile consistent with a 4 × 10^(12) M_⊙ halo. The orbital time of the outer part of the what we term a "protodisk" is comparable to the virialization time and the age of the universe at this redshift. We propose that this protodisk can only have recently formed from cold gas flowing directly from the cosmic web.

Item Type:Article
Related URLs:
URLURL TypeDescription
Martin, D. Christopher0000-0002-8650-1644
Morrissey, Patrick0000-0001-8177-1023
Neill, James D.0000-0002-0466-1119
Moore, Anna0000-0002-2894-6936
Steidel, Charles C.0000-0002-4834-7260
Trainor, Ryan0000-0002-6967-7322
Additional Information:© 2016 The American Astronomical Society. Received 2016 February 23; revised 2016 April 11; accepted 2016 April 13; published 2016 June 3. This work was supported by the National Science Foundation and the California Institute of Technology. R.F.T. receives financial support from the UC Berkeley Miller Institute for Basic Research in Science.
Group:Space Astrophysics Laboratory
Funding AgencyGrant Number
Miller Institute for Basic Research in ScienceUNSPECIFIED
Subject Keywords:dark matter; galaxies: evolution; galaxies: formation; galaxies: high-redshift; intergalactic medium; quasars: general
Issue or Number:1
Record Number:CaltechAUTHORS:20160707-085528559
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Official Citation:D. Christopher Martin et al 2016 ApJ 824 L5
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:68880
Deposited By: Ruth Sustaita
Deposited On:07 Jul 2016 19:33
Last Modified:09 Mar 2020 23:37

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