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

作者：Monje R R^*; Phillips T G; Peng R; Lis D C; Neufeld D A; Emprechtinger M

来源：Astrophysical Journal Letters, 2011, 742(2): L21.

DOI：10.1088/2041-8205/742/2/L21

• astrochemistry
• cosmology: observations
• ISM: individual objects (Cloverleaf)
• ISM: molecules

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 similar to 6 sigma level. We estimate a lower limit of 4 x 10(14) 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 x 10(-9) for the HF abundance. This value suggests that, assuming a Galactic N(HF)/N(H) ratio, HF accounts for at least similar to 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).

• 出版日期2011-12-1