Discovery of Hydrogen Fluoride in the Cloverleaf Quasar at z = 2.56
Abstract
We report the first detection of hydrogen fluoride (HF) toward a high-redshift quasar. Using the Caltech Submillimeter Observatory, we detect the HF J = 1-0 transition in absorption toward the Cloverleaf, a broad absorption line quasi-stellar object at z = 2.56. The detection is statistically significant at the ~6σ level. We estimate a lower limit of 4 × 1014 cm-2 for the HF column density and using a previous estimate of the hydrogen column density, we obtain a lower limit of 1.7 × 10-9 for the HF abundance. This value suggests that, assuming a Galactic N(HF)/N H ratio, HF accounts for at least ~10% of the fluorine in the gas phase along the line of sight to the Cloverleaf quasar. This observation corroborates the prediction that HF should be a good probe of the molecular gas at high redshift. Measurements of the HF abundance as a function of redshift are urgently needed to better constrain the fluorine nucleosynthesis mechanism(s).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 2011
- DOI:
- 10.1088/2041-8205/742/2/L21
- arXiv:
- arXiv:1201.4882
- Bibcode:
- 2011ApJ...742L..21M
- Keywords:
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- astrochemistry;
- cosmology: observations;
- ISM: individual objects: Cloverleaf;
- ISM: molecules;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- 2011ApJ...742L..21M