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DISCOVERY OF HYDROGEN FLUORIDE IN THE CLOVERLEAF QUASAR AT z = 2.56

2011; IOP Publishing; Volume: 742; Issue: 2 Linguagem: Inglês

10.1088/2041-8205/742/2/l21

2041-8213

Raquel Rodriguez Monje, T. G. Phillips, R. Peng, D. C. Lis, D. A. Neufeld, M. Emprechtinger,

Stellar, planetary, and galactic studies

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)/NH 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).