Skip to main content

Research Repository

Advanced Search

ALMA Observations of Lyα Blob 1: Multiple Major Mergers and Widely Distributed Interstellar Media

Umehata, Hideki; Smail, Ian; Steidel, Charles C.; Hayes, Matthew; Scott, Douglas; Swinbank, A.M.; Ivison, R.J.; Nagao, Toru; Kubo, Mariko; Nakanishi, Kouichiro; Matsuda, Yuichi; Ikarashi, Soh; Tamura, Yoichi; Geach, J.E.

ALMA Observations of Lyα Blob 1: Multiple Major Mergers and Widely Distributed Interstellar Media Thumbnail


Authors

Hideki Umehata

Charles C. Steidel

Matthew Hayes

Douglas Scott

R.J. Ivison

Toru Nagao

Mariko Kubo

Kouichiro Nakanishi

Yuichi Matsuda

Soh Ikarashi

Yoichi Tamura

J.E. Geach



Abstract

We present observations of a giant Lyα blob (LAB) in the SSA22 protocluster at z = 3.1, SSA22-LAB1, taken with the Atacama Large Millimeter/submillimeter Array. Dust continuum, along with [C ii] 158 μm and CO(4–3) line emission have been detected in LAB1, showing complex morphology and kinematics across a ∼100 kpc central region. Seven galaxies at z = 3.0987–3.1016 in the surroundings are identified in [C ii] and dust continuum emission, with two of them potential companions or tidal structures associated with the most massive galaxies. Spatially resolved [C ii] and infrared luminosity ratios for the widely distributed media (L[Cɪɪ]/LIR ≈ 10−2−10−3) suggest that the observed extended interstellar media are likely to have originated from star formation activity and the contribution from shocked gas is probably not dominant. LAB1 is found to harbor a total molecular gas mass Mmol = (8.7 ± 2.0) × 1010 M⊙, concentrated in the core region of the Lyα-emitting area. While (primarily obscured) star formation activity in the LAB1 core is one of the most plausible power sources for the Lyα emission, multiple major mergers found in the core may also play a role in making LAB1 exceptionally bright and extended in Lyα as a result of cooling radiation induced by gravitational interactions.

Citation

Umehata, H., Smail, I., Steidel, C. C., Hayes, M., Scott, D., Swinbank, A., …Geach, J. (2021). ALMA Observations of Lyα Blob 1: Multiple Major Mergers and Widely Distributed Interstellar Media. Astrophysical Journal, 918(2), Article 69. https://doi.org/10.3847/1538-4357/ac1106

Journal Article Type Article
Acceptance Date Jul 1, 2021
Online Publication Date Sep 9, 2021
Publication Date 2021
Deposit Date Nov 10, 2021
Publicly Available Date Nov 11, 2021
Journal Astrophysical Journal
Print ISSN 0004-637X
Electronic ISSN 1538-4357
Publisher American Astronomical Society
Peer Reviewed Peer Reviewed
Volume 918
Issue 2
Article Number 69
DOI https://doi.org/10.3847/1538-4357/ac1106

Files

Published Journal Article (3 Mb)
PDF

Copyright Statement
© 2021. The American Astronomical Society. All rights reserved.






You might also like



Downloadable Citations