A DEEP SEARCH FOR CO J = 2-1 EMISSION FROM A Ly{alpha} BLOB AT z {approx} 6.595

Journal Article · Fri Jun 01 04:00:00 EDT 2012 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/751/2/L24· OSTI ID:22047796

Wagg, Jeff ^[1]; Kanekar, Nissim ^[2]

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1. European Southern Observatory, Casilla 19001, Santiago (Chile)
2. National Centre for Radio Astrophysics, TIFR, Ganeshkhind, Pune 411007 (India)

We have used the Green Bank Telescope to carry out a deep search for redshifted CO J = 2-1 line emission from an extended (>17 kpc) Ly{alpha} blob (LAB), 'Himiko', at z {approx} 6.595. Our non-detection of CO J = 2-1 emission places the strong 3{sigma} upper limit of L'{sub CO} < 1.8 Multiplication-Sign 10{sup 10} Multiplication-Sign ({Delta}V/250){sup 1/2} K km s{sup -1} pc{sup 2} on the CO line luminosity. This is comparable to the best current limits on the CO line luminosity in LABs at z {approx} 3 and lower-luminosity Ly{alpha} emitters at z {approx}> 6.5. High-z LABs appear to have lower CO line luminosities than the host galaxies of luminous quasars and submillimeter galaxies at similar redshifts, despite their high stellar mass. Although the CO-to-H{sub 2} conversion factor is uncertain for galaxies in the early universe, we assume X{sub CO} = 0.8 M{sub Sun} (K km s{sup -1} pc{sup 2}){sup -1} to obtain the limit M(H{sub 2}) <1.4 Multiplication-Sign 10{sup 10} M{sub Sun} on Himiko's molecular gas mass; this is a factor of {approx}> 2.5 lower than the stellar mass in the z {approx} 6.595 LAB.

• OSTI ID: 22047796
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 751; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
CARBON MONOXIDE
DETECTION
GALAXIES
HYDROGEN
LUMINOSITY
LYMAN LINES
MASS
PHOTON EMISSION
QUASARS
RED SHIFT
STARS
TELESCOPES
UNIVERSE