ﻻ يوجد ملخص باللغة العربية
We present the detection of molecular oxygen with Odin toward the dense molecular core rho Oph A, which is part of a region of active star formation. The observed spectral line is the (N,J = 1,1-1,0) ground state transition of molecular oxygen at 119 GHz (2.5 mm wavelength). The center of the line is at the LSR velocity of a number of optically thin lines from other species in the region and the O2 line also has a very similar, narrow, line width. Within the 10 arcmin beam, the integrated line intensity is 28 mK km/s, which corresponds to 5 sigma of the rms noise. A standard LTE analysis results in an O2 abundance of 5E(-8), with an uncertainty of at least a factor of two. We show that standard methods, however, do not apply in this case, as the coupling of the Odin beam to the source structure needs to be accounted for. Preliminary model results indicate O2 abundances to be higher by one order of magnitude than suggested by the standard case. This model predicts the 487 GHz line of O2 to be easily detectable by the future Herschel-HIFI facility, but to be out of reach for observations on a shorter time scale with the Odin space observatory.
The Odin satellite has been used to search for the 118.75-GHz line of molecular oxygen (O2)in the Galactic centre. Odin observations were performed towards the Sgr A* circumnuclear disk (CND), and the Sgr A +20 km/s and +50 km/s molecular clouds usin
Models of pure gas-phase chemistry in well-shielded regions of molecular clouds predict relatively high levels of molecular oxygen, O2, and water, H2O. Contrary to expectation, the space missions SWAS and Odin found only very small amounts of water v
Aims. In this paper we investigate the detectability of the molecular oxygen in icy dust grain mantles towards astronomical objects. Methods. We present a systematic set of experiments with O2-H2O ice mixtures designed to disentangle how the molecula
The Odin satellite has been used to detect emission and absorption in the 557-GHz H2O line in the Galactic Centre towards the Sgr A* Circumnuclear Disk (CND), and the Sgr A +20 km/s and +50 km/s molecular clouds. Strong broad H2O emission lines have
Environmental research aimed at monitoring and predicting O2 depletion is still lacking or in need of improvement, in spite of many attempts to find a relation between atmospheric gas content and climate variability. The aim of the present project is