The Herschel view of massive star formation in G035.39--00.33: a dense and cold filament of W48 undergoing a mini-starburst

Q. Nguyen Luong , F. Motte (1, 2) , M. Hennemann (1) , T. Hill (1) , K. L. J. Rygl , N. Schneider (1) , Sylvain Bontemps (3, 4, 5, 6) , A. Men'Shchikov (1) , Ph. André (1) , N. Peretto (1) , L. D. Anderson (7) , D. Arzoumanian , L. Deharveng (7, 8) , P. Didelon (1) , J. Di Francesco (9) , M. J. Griffin , J. M. Kirk , V. Konyves , P. G. Martin (10) , A. Maury (11) , V. Minier (1, 2) , S. Molinari (12) , M. Pestalozzi , S. Pezzuto (12) , M. Reid (13) , Hervé Roussel (14) , F. Schuller (15) , L. Testi (11) , D. Ward-Thompson (16) , G. J. White (17) , Annie Zavagno (7, 8)

1 AIM (UMR7158 / UMR_E_9005 / UM_112) - Astrophysique Interprétation Modélisation
2 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
3 OASU - Observatoire aquitain des sciences de l'univers
4 UB - Université Sciences et Technologies - Bordeaux 1
5 LAB - Laboratoire d'Astrophysique de Bordeaux [Pessac]
6 L3AB - Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux
7 LAM - Laboratoire d'Astrophysique de Marseille
8 OAMP - Observatoire Astronomique de Marseille Provence
9 Herzberg Institute of Astrophysics
10 LM2C - Laboratoire de Modélisation Multi-échelles des Combustibles
11 ESO - European Southern Observatory
12 IFSI - Istituto di Fisica dello Spazio Interplanetario
13 CTVR/Stokes Institute, Engineering Research Building
14 IAP - Institut d'Astrophysique de Paris
15 MPIFR - Max-Planck-Institut für Radioastronomie
16 School of Physics and Astronomy [Cardiff]
17 Engineering Department

The filament IRDC G035.39-00.33 in the W48 molecular complex is one of the darkest infrared clouds observed by Spitzer. It has been observed by the PACS (70 and 160 micron) and SPIRE (250, 350 and 500) cameras of the \textit{Herschel} Space Observatory as part of the W48 molecular cloud complex in the framework of the HOBYS key programme. The observations reveal a sample of 28 compact sources (deconvolved FWHM sizes < 0.3 pc) complete down to ~5 solar mass in G035.39-00.33 and its surroundings. Among them, 13 compact sources are massive dense cores with masses >20 solar mass. The cloud characteristics we derive from the analysis of their spectral energy distributions (20-50 solar mass with sizes of 0.1-0.2 pc and average densities of 2-20 x 10^5 cm^3) make these massive dense cores excellent candidates to form intermediate- to high-mass stars. Most of the massive dense cores are located inside the G035.39-00.33 filament and host IR-quiet high-mass protostars. The large number of protostars found in this filament suggests that we are witnessing a mini-burst of star formation with an efficiency of ~20% and a rate density of ~40 solar mass per year per kpc^2 within a ~8 pc^2 area. Part of the extended SiO emission observed toward G035.39-00.33 is not associated with obvious protostars and may originate from low-velocity shocks within converging flows, as advocated by previous studies.

Domaines: Astrophysique stellaire et solaire [astro-ph.SR]; Astrophysique stellaire et solaire [astro-ph.SR]

Q. Nguyen Luong, F. Motte, M. Hennemann, T. Hill, K. L. J. Rygl, et al.. The Herschel view of massive star formation in G035.39--00.33: a dense and cold filament of W48 undergoing a mini-starburst. Astronomy and Astrophysics - A&A, 2011, 535, pp.id.A76. ⟨10.1051/0004-6361/201117831⟩. ⟨hal-00624630⟩