Thermal balance and comparison of gas and dust properties of dense clumps in the Hi-GAL survey

Autor(es)

Merello, M. ^{[1, 2]} ; Molinari, S. ^[1] ; Rygl, K. L. J. ^[3] ; Evans, II, N. J. ; Elia, D. ^[1] ; Schisano, E. ^[1] ; Traficante, A. ^[1] ; Shirley, Y. ^[4] ; Svoboda, B. ^[4] ; Goldsmith, P. F. ^[5]

Afiliação do(s) autor(es)

^[1] INAF Ist Astrofis & Planetol Spaziale, Via Fosso Cavaliere 100, I-00133 Rome - Italy

^[2] Univ Sao Paulo, IAG, Rua Matao 1226, BR-05508090 Sao Paulo - Brazil

^[3] INAF IRA, Italian ALMA Reg Ctr, Via P Gobetti 101, I-40129 Bologna - Italy

^[4] Univ Arizona, Steward Observ, 933 North Cherry Ave, Tucson, AZ 85721 - USA

^[5] CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 - USA

• Tipo de documento: Artigo Científico
• Fonte: Monthly Notices of the Royal Astronomical Society; v. 483, n. 4, p. 5355-5379, MAR 2019.
• Citações Web of Science: 2

Resumo

We present a comparative study of physical properties derived from gas and dust emission in a sample of 1068 dense Galactic clumps. The sources are selected from the cross-match of the Herschel Infrared Galactic Plane Survey with 16 catalogues of NH3 line emission in its lowest inversion (1,1) and (2,2) transitions. The sample covers a large range in masses and bolometric luminosities, with surface densities above Sigma = 0.1 g cm(-2) and with low virial parameters alpha < 1. The comparison between dust and gas properties shows an overall agreement between T-kin and T-dust at volumetric densities n greater than or similar to 1.2 x 10(4)cm(-3), and a median fractional abundance chi (NH3) = 1.46 x 10(-8). While the protostellar clumps in the sample have small differences between T-kin and T-dust, prestellar clumps have a median ratio T-kin/T-dust = 1.24, suggesting that these sources are thermally decoupled. A correlation is found between the evolutionary tracer L/M and the parameters T-kin/T-dust and chi(NH3) in prestellar sources and protostellar clumps with L/M < 1 L circle dot M circle dot-1 . In addition, a weak correlation is found between non-thermal velocity dispersion and the L/M parameter, possibly indicating an increase of turbulence with protostellar evolution in the interior of clumps. Finally, different processes are discussed to explain the differences between gas and dust temperatures in prestellar candidates, and the origin of non-thermal motions observed in the clumps. (AU)

• Processo FAPESP: 17/23708-0 - Galáxias com emissão megamaser de H2O e calibrações de intensidade em radioastronomia
• Beneficiário: Manuel Antonio Merello Ferrada
• Linha de fomento: Bolsas no Brasil - Pós-Doutorado