A 100 Mpc<sup>2</sup> Structure Traced by Hyperluminous Galaxies around a Massive <i>z</i> = 2.85 Protocluster
Abstract We present wide-field mapping at 850 μ m and 450 μ m of the z = 2.85 protocluster in the HS 1549+19 field using the Submillimetre Common-User Bolometer Array 2. Spectroscopic follow-up of 18 bright sources selected at 850 μ m, using the Northern Extended Millimeter Array and Atacama Large Millimeter/submillimeter Array, confirms that the majority lie near z ≃ 2.85 and are likely members of the structure. Interpreting the spectroscopic redshifts as distance measurements, we find that the submillimeter galaxies (SMGs) span 123 pMpc 2 in the plane of the sky and demarcate a 3600 pMpc 3 “pancake”-shaped structure in three dimensions. We find that the high star formation rates of these SMGs result in a total star formation rate of 20,000 M ⊙ yr −1 from just the brightest galaxies in the protocluster. These rapidly star-forming SMGs can be interpreted as massive galaxies growing rapidly at large clustercentric distances before collapsing into a virialized structure. We find that the SMGs trace the Ly α surface density profile. Comparison with simulations suggests that HS 1549+19 could be building a structure comparable to the most massive clusters in the present-day Universe.
Authors
- D. Scott (ORCID: https://orcid.org/0000-0002-6878-9840)
- F. Bertoldi (ORCID: https://orcid.org/0000-0002-1707-1775)
- Satoshi Kikuta (ORCID: https://orcid.org/0000-0003-3214-9128)
- Charles C. Steidel (ORCID: https://orcid.org/0000-0002-4834-7260)
- Douglas Rennehan (ORCID: https://orcid.org/0000-0002-1619-8555)
- Christopher C. Hayward (ORCID: https://orcid.org/0000-0003-4073-3236)
- Ian Smail (ORCID: https://orcid.org/0000-0003-3037-257X)
- Yuichi Matsuda (ORCID: https://orcid.org/0000-0003-1747-2891)
- Ryley Hill (ORCID: https://orcid.org/0009-0008-8718-0644)
- S. C. Chapman (ORCID: https://orcid.org/0000-0002-8487-3153)
- Nikolaus Sulzenauer (ORCID: https://orcid.org/0000-0002-3187-1648)
- George C. P. Wang (ORCID: https://orcid.org/0009-0003-4626-9777)
Institutions
- California Institute of Technology (US)
- Herzberg Institute of Astrophysics (CA)
- Dalhousie University (CA)
- University of Bonn (DE)
- University of British Columbia (CA)
- Durham University (GB)
- The Graduate University for Advanced Studies, SOKENDAI (JP)
- Eureka Scientific (US)
- Flatiron Health (United States) (US)
- Max Planck Institute for Radio Astronomy (DE)
- National Astronomical Observatory of Japan (JP)
- Flatiron Institute (US)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2025-04-07
- DOI
- https://doi.org/10.3847/1538-4357/adb834
- Citations
- 4
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 4.62
Funders
- National Radio Astronomy Observatory