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| EPoS Contribution |
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CO-depletion within IRDC: the case study of G351.77-0.51
Giovanni Sabatini INAF-IRA-ItARC & DiFA-UniBo, Bologna, IT | |
| Knowledge of the degree of CO-depletion provides information on the physical conditions occurring in the innermost and densest regions of molecular clouds. A key parameter is the radius within which the CO is depleted (Rdep). In this contribution, we present a case study of CO-depletion in the Infrared Dark Cloud G351.77-0.51 (G351; see Fig.1). We model Herschel (Hi-Gal) and LABOCA dust continuum data, combined with APEX C18O and C17O J(2-1) line observations, to investigate the CO-depletion along the filament and its inner condensations. Our model shows that Rdep ranges from 0.02 to 0.15 pc (exploring several initial conditions), in agreement with the evidence of a typical filament width (i.e.∼0.1 pc). At these radii, the number density of H2 reaches values between 0.2 and 5.5×105 cm-3. These results provide information on the spatial scales across which different chemical processes operate, and provide us with an upper limit on Rdep, below which CO emission cannot be used to infer the gas kinematics. I will discuss these results and the need of new molecular tracers to study the inner filament regions. | |
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| Caption: Depletion factor (fD) map obtained by taking the ratio between the expected (i.e. C18O/H2 = 2.1×10-7) and observed abundances of C18O relative to H2. The cyan contours are the 3, 9, 27 and 81σ contours of the APEX C18O integrated flux density distribution, while the ones in magenta are defined at fD = 1.5, 2, 3, 4 and 5. The black labels indicate some of the dust clumps identified by Leurini et al. (2011b). Red stars in clump-5 and -7 indicate locations of the clumps reported in Leurini et al. (2019), while the one in clump-3 identifies the candidate HII region reported in Anderson et al. (2014). The plot is from Sabatini et al. (2019). | |
| Collaborators: A. Giannetti, INAF-IRA-ItARC, IT S. Bovino, Departamento de Astronomia - UdeC, CL J. Brand, INAF-IRA-ItARC, IT S. Leurini, OAC, IT E. Schisano, IAPS, IT T. Pillai,IAR, US K. M. Menten, IMPRS, DE |
Key publication
Suggested Session: Molecular Clouds |