Abstract
Aims: The work described here uses heterodyne spectroscopy from space to search for molecular oxygen in the interstellar medium.
Methods: The Odin satellite carries a 1.1 m sub-millimeter dish and a dedicated 119 GHz receiver for the ground state line of O2. Starting in 2002, the star forming molecular cloud core ρ {Oph A} was observed with Odin for 34 days during several observing runs.
Results: We detect a spectral line at v_LSR =+3.5 km s-1 with Δ v_FWHM=1.5 km s-1, parameters which are also common to other species associated with ρ {Oph A}. This feature is identified as the O2 (NJ = 11 - 1_0) transition at 118 750.343 MHz.
Conclusions: The abundance of molecular oxygen, relative to H{2} , is 5 × 10-8 averaged over the Odin beam. This abundance is consistently lower than previously reported upper limits.
Original language | English |
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Pages (from-to) | 999-1003 |
Number of pages | 5 |
Journal | Astronomy & Astrophysics |
Volume | 466 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2007 |
Externally published | Yes |
Keywords
- ISM: individual objects: ρ Oph A; ISM: clouds; ISM: molecules; ISM: abundances; stars: formation; radio lines: ISM; Astrophysics