[C II] LINE EMISSION IN MASSIVE STAR-FORMING GALAXIES AT z = 4.7

Journal Article · Wed Jun 20 00:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/752/2/L30· OSTI ID:22047737

Wagg, J; Aravena, M; Martin, S ^[1]; Wiklind, T; Peck, A; Barkats, D; Cortes, J R; Hills, R; Hodge, J; Impellizzeri, C M V.; Rawlings, M G ^[2]; Carilli, C L ^[3]; Espada, D; Iono, D ^[4]; Riechers, D ^[5]; Walter, F ^[6]; Wootten, A; Leroy, A ^[7]; Maiolino, R ^[8]; others, and

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1. European Southern Observatory, Casilla 19001, Santiago (Chile)
2. Joint ALMA Observatory, Alonso de Cordova 3107, Vitacura, Santiago (Chile)
3. National Radio Astronomy Observatory, Socorro, NM (United States)
4. National Astronomical Observatory of Japan, Tokyo (Japan)
5. Department of Astronomy, California Institute of Technology, Pasadena, CA (United States)
6. Max-Planck Institute for Astronomy, Heidelberg (Germany)
7. National Radio Astronomy Observatory, Charlottesville, VA (United States)
8. Cavendish Laboratory, University of Cambridge, Cambridge (United Kingdom)

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the [C II] 157.7 {mu}m fine structure line and thermal dust continuum emission from a pair of gas-rich galaxies at z = 4.7, BR1202-0725. This system consists of a luminous quasar host galaxy and a bright submillimeter galaxy (SMG), while a fainter star-forming galaxy is also spatially coincident within a 4'' (25 kpc) region. All three galaxies are detected in the submillimeter continuum, indicating FIR luminosities in excess of 10{sup 13} L{sub Sun} for the two most luminous objects. The SMG and the quasar host galaxy are both detected in [C II] line emission with luminosities L{sub [CII]} = (10.0 {+-} 1.5) Multiplication-Sign 10{sup 9} L{sub Sun} and L{sub [CII]} = (6.5 {+-} 1.0) Multiplication-Sign 10{sup 9} L{sub Sun }, respectively. We estimate a luminosity ratio L{sub [CII]}/L{sub FIR} = (8.3 {+-} 1.2) Multiplication-Sign 10{sup -4} for the starburst SMG to the north and L{sub [CII]}/L{sub FIR} = (2.5 {+-} 0.4) Multiplication-Sign 10{sup -4} for the quasar host galaxy, in agreement with previous high-redshift studies that suggest lower [C II]-to-FIR luminosity ratios in quasars than in starburst galaxies. The third fainter object with a flux density S{sub 340GHz} = 1.9 {+-} 0.3 mJy is coincident with a Ly{alpha} emitter and is detected in HST ACS F775W and F814W images but has no clear counterpart in the H band. Even if this third companion does not lie at a redshift similar to BR1202-0725, the quasar and the SMG represent an overdensity of massive, infrared luminous star-forming galaxies within 1.3 Gyr of the big bang.

• OSTI ID: 22047737
• Journal Information: Astrophysical Journal Letters, Vol. 752, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ASTROPHYSICS
CARBON IONS
COSMOLOGY
EMISSION
FAR INFRARED RADIATION
FINE STRUCTURE
FLUX DENSITY
GALAXIES
IMAGES
LUMINOSITY
PHOTON EMISSION
QUASARS
RED SHIFT
STAR EVOLUTION
STARS
UNIVERSE