Kinetic temperatures toward X1-X2 orbit interceptions regions and giant molecular loops in the Galactic center regionReport as inadecuate




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Context. It is well known that the kinetic temperatures, Tkin, of the molecular clouds in the Galactic center region are higher than intypical disk clouds. However, the Tkin of the molecular complexes found at higher latitudes towards the giant molecular loops in thecentral region of the Galaxy is so far unknown. The gas of these high-latitude molecular clouds hereafter referred to as -halo clouds-is located in a region where the gas in the disk may interact with the gas in the halo in the Galactic center region.Aims. To derive Tkin in the molecular clouds at high latitude and understand the physical process responsible for the heating of themolecular gas both in the central molecular zone the concentration of molecular gas in the inner ∼500 pc and in the giant molecularloops.Methods. We measured the metastable inversion transitions of NH3 from J, K = 1, 1 to 6, 6 toward six positions selected throughoutthe Galactic central disk and halo.We used rotational diagrams and large velocity gradient LVG modeling to estimate the kinetictemperatures toward all the sources. We also observed other molecules like SiO, HNCO, CS, C34S, C18O, and 13CO, to derive thedensities and to trace different physical processes shocks, photodissociation, dense gas expected to dominate the heating of themolecular gas.Results. We derive for the first time Tkin of the high-latitude clouds interacting with the disk in the Galactic center region. We findhigh rotational temperatures in all the observed positions. We derive two kinetic temperature components ∼150 K and ∼40 K forthe positions in the central molecular zone, and only the warm kinetic temperature component for the clouds toward the giant molecularloops. The fractional abundances derived from the different molecules suggest that shocks provide the main heating mechanismthroughout the Galactic center, also at high latitudes.Nota general

Artículo de publicación ISI



Author: Riquelme, D.; - Amo Baladrón, M. A.; - Martín Pintado, J.; - Mauersberger, R.; - Bronfman Aguiló, Leonardo; - Martín, S.; -

Source: http://repositorio.uchile.cl/



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