A Search for C II 158 μm Line Emission in HCM 6A, a Lyα Emitter at z = 6.56
Abstract
We report a Plateau de Bure Interferometer search for CII 158μm emission from HCM 6A, a lensed Lyα emitter (LAE) at z = 6.56. Our non-detections of CII 158μm line emission and 1.2 mm radio continuum emission yield 3σ limits of L_CII < 6.4×10^7×(ΔV/100 km s^−1)^(1/2) L_☉ for the CII 158μm line luminosity and S1.2mm < 0.68 mJy for the 1.2 mm flux density. The local conversion factor between L_CII and the star formation rate (SFR) yields an SFR<4.7M_☉ yr^−1, ≈2 times lower than that inferred from the ultraviolet (UV) continuum, suggesting that the local factor may not be applicable in high-z LAEs. The non-detection of 1.2 mm continuum emission yields a total SFR<28M_☉ yr^−1; any obscured star formation is thus within a factor of two of the visible star formation. Our best-fit model to the rest-frame UV/optical spectral energy distribution of HCM 6A yields a stellar mass of 1.3 × 10^9 M_☉ and an SFR of ≈10M_☉ yr^−1, with negligible dust obscuration. We fortuitously detect CO J=3–2 emission from a z = 0.375 galaxy in the foreground cluster A370, and obtain a CO line luminosity of L'(CO) > (8.95 ± 0.79) × 10^8 K km s^−1 pc^2 and a molecular gas mass of M(H_2) > (4.12 ± 0.36) × 10^9 M_☉, for a CO-to-H_2 conversion factor of 4.6M_☉ (K km s^−1 pc^2)^−1.
Additional Information
© 2013 American Astronomical Society. Received 2013 March 8; accepted 2013 May 22; published 2013 June 20. N.K., J.W., and C.C. are grateful for support from the Max- Planck Society and the Alexander von Humboldt Foundation. N.K. acknowledges support from the Department of Science and Technology through a Ramanujan Fellowship. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.Attached Files
Published - 2041-8205_771_2_L20.pdf
Submitted - 1305.6469v2.pdf
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Additional details
- Alternative title
- A Search for C II 158 μm Line Emission in HCM 6A, a Lyman-α Emitter at z = 6.56
- Eprint ID
- 39893
- Resolver ID
- CaltechAUTHORS:20130813-114045818
- Max Planck Society
- Alexander von Humboldt Foundation
- Department of Science and Technology (India)
- Created
-
2013-08-14Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)