A study of the C_3H_2 isomers and isotopologues: first interstellar detection of HDCCC
Abstract
We present ALMA detections of the [NII] 205 μm and CO(12−11) emission lines, and the tentative detection of [CI] ^3P_1–^3P_0 for the strongly lensed (μ = 5.7 ± 0.5) dusty, star-forming galaxy SPT-S J213242-5802.9 (hereafter SPT2132-58) at z = 4.77. The [NII] and CO(12−11) lines are detected at 11.5 and 8.5σ levels, respectively, by our band 6 observations. The [CI] line is detected at 3.2σ after a reanalysis of existing band 3 data. The [CI] luminosity implies a gas mass of (3.8 ± 1.2) × 10^(10)M_⊙, and, consequently, a very short depletion timescale of 34 ± 13 Myr and a CO luminosity to gas mass conversion factor α_(CO) of 1.0 ± 0.3 M_⊙ (K km s^(-1) pc^2)^(-1). SPT2132-58 is an extreme starburst with an intrinsic star formation rate of 1100 ± 200 M_⊙/yr. We find a [CII]/[NII] ratio of 26 ± 6, which is the highest ratio reported at z > 4. This suggests that SPT2132-58 hosts an evolved interstellar medium (0.5 Z_⊙< Z < 1.5 Z_⊙), which may be dominated by photodissociation regions. The CO(2−1) and CO(5−4) transitions have lower CO to far-infrared ratios than local and high-redshift samples, while CO(12−11) is similar to these samples, suggesting the presence of an additional very excited component or an active galactic nucleus.
Additional Information
© 2016 ESO. Received 28 September 2015. Accepted 12 November 2015. Published online 02 February 2016. This work is carried out within the Collaborative Research Centre 956, sub-project [B2], funded by the Deutsche Forschungsgemeinschaft (DFG), and has also been supported by the NASA grant NNX13AE59G. S. Spezzano wishes to thank the Bonn Cologne Graduate School of Physics and Astronomy (BCGS) for financial support. Any opinions, findings, and conclusions in this article are those of the authors and do not necessarily reflect the views of the National Science Foundation.Attached Files
Published - aa27460-15.pdf
Submitted - 1511.04878v1.pdf
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Additional details
- Eprint ID
- 65334
- Resolver ID
- CaltechAUTHORS:20160314-122018803
- Deutsche Forschungsgemeinschaft (DFG)
- NNX13AE59G
- NASA
- Bonn Cologne Graduate School of Physics and Astronomy (BCGS)
- Created
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2016-03-14Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field