ALMA OBSERVATIONS OF Ly α BLOB 1: HALO SUBSTRUCTURE ILLUMINATED FROM WITHIN

Journal Article · Sun Nov 20 00:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/832/1/37· OSTI ID:22667197

Geach, J. E. ^[1]; Narayanan, D. ^[2]; Matsuda, Y.; Ao, Y.; Kubo, M. ^[3]; Hayes, M. ^[4]; Mas-Ribas, Ll.; Dijkstra, M. ^[5]; Steidel, C. C. ^[6]; Chapman, S. C. ^[7]; Feldmann, R. ^[8]; Avison, A. ^[9]; Agertz, O. ^[10]; Birkinshaw, M.; Bremer, M. N. ^[11]; Clements, D. L. ^[12]; Dannerbauer, H. ^[13]; Farrah, D. ^[14]; Harrison, C. M. ^[15]; others, and

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1. Centre for Astrophysics Research, University of Hertfordshire, Hatfield, AL10 9AB (United Kingdom)
2. Dept. of Physics and Astronomy, Haverford College, PA 19041 (United States)
3. National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan)
4. Stockholm University, Dept. of Astronomy and Oskar Klein Centre for Cosmoparticle Physics, SE-10691, Stockholm (Sweden)
5. Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029 Blindern, NO-0315 Oslo (Norway)
6. California Institute of Technology, 1216 East California Boulevard, MS 249-17, Pasadena, CA 91125 (United States)
7. Dept. of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 4R2 (Canada)
8. Dept. of Astronomy, University of California Berkeley, CA 94720 (United States)
9. UK ALMA Regional Centre Node, Manchester (United Kingdom)
10. Dept. of Physics, University of Surrey, GU2 7XH, Surrey (United Kingdom)
11. H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL (United Kingdom)
12. Astrophysics Group, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom)
13. Instituto de Astrofísica de Canarias, La Laguna, Tenerife (Spain)
14. Dept. of Physics, Virginia Tech, Blacksburg, VA 24061 (United States)
15. Centre for Extragalactic Astronomy, Dept. of Physics, Durham University, South Road, Durham, DH1 3LE (United Kingdom)

We present new Atacama Large Millimeter/Submillimeter Array (ALMA) 850 μ m continuum observations of the original Ly α Blob (LAB) in the SSA22 field at z = 3.1 (SSA22-LAB01). The ALMA map resolves the previously identified submillimeter source into three components with a total flux density of S {sub 850} = 1.68 ± 0.06 mJy, corresponding to a star-formation rate of ∼150 M {sub ⊙} yr{sup -1}. The submillimeter sources are associated with several faint ( m ≈ 27 mag) rest-frame ultraviolet sources identified in Hubble Space Telescope Imaging Spectrograph (STIS) clear filter imaging ( λ ≈ 5850 Å). One of these companions is spectroscopically confirmed with the Keck Multi-Object Spectrometer For Infra-Red Exploration to lie within 20 projected kpc and 250 km s{sup -1} of one of the ALMA components. We postulate that some of these STIS sources represent a population of low-mass star-forming satellites surrounding the central submillimeter sources, potentially contributing to their growth and activity through accretion. Using a high-resolution cosmological zoom simulation of a 10{sup 13} M {sub ⊙} halo at z = 3, including stellar, dust, and Ly α radiative transfer, we can model the ALMA+STIS observations and demonstrate that Ly α photons escaping from the central submillimeter sources are expected to resonantly scatter in neutral hydrogen, the majority of which is predicted to be associated with halo substructure. We show how this process gives rise to extended Ly α emission with similar surface brightness and morphology to observed giant LABs.

• OSTI ID: 22667197
• Journal Information: Astrophysical Journal, Vol. 832, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
BRIGHTNESS
COSMIC DUST
EMISSION
FLUX DENSITY
GALAXIES
HYDROGEN
LYMAN LINES
MASS
PHOTONS
RADIANT HEAT TRANSFER
RED SHIFT
SATELLITES
SIMULATION
SPACE
SPECTROMETERS
STAR EVOLUTION
STARS
TELESCOPES
ULTRAVIOLET RADIATION