Clouds, filaments and protostars: the Herschel Hi-GAL Milky Way
Abstract
We present the first results from the science demonstration phase for the Hi-GAL survey, the Herschel key-project that will map the inner Galactic Plane of the Milky Way in 5 bands. We outline our data reduction strategy and present some science highlights on the two observed 2{\deg} x 2{\deg} tiles approximately centered at l=30{\deg} and l=59{\deg}. The two regions are extremely rich in intense and highly structured extended emission which shows a widespread organization in filaments. Source SEDs can be built for hundreds of objects in the two fields, and physical parameters can be extracted, for a good fraction of them where the distance could be estimated. The compact sources (which we will call 'cores' in the following) are found for the most part to be associated with the filaments, and the relationship to the local beam-averaged column density of the filament itself shows that a core seems to appear when a threshold around A_V of about 1 is exceeded for the regions in the l=59{\deg} field; a A_V value between 5 and 10 is found for the l=30{\deg} field, likely due to the relatively larger distances of the sources. This outlines an exciting scenario where diffuse clouds first collapse into filaments, which later fragment to cores where the column density has reached a critical level. In spite of core L/M ratios being well in excess of a few for many sources, we find core surface densities between 0.03 and 0.5 g cm-2. Our results are in good agreement with recent MHD numerical simulations of filaments forming from large-scale converging flows.
Keywords
Cite
@article{arxiv.1005.3317,
title = {Clouds, filaments and protostars: the Herschel Hi-GAL Milky Way},
author = {S. Molinari and B. Swinyard and J. Bally and M. Barlow and J. P. Bernard and P. Martin and T. Moore and A. Noriega-Crespo and R. Plume and L. Testi and A. Zavagno and A. Abergel and B. Ali and L. Anderson and P. André and J. P. Baluteau and C. Battersby and M. T. Beltrán and M. Benedettini and N. Billot and J. Blommaert and S. Bontemps and F. Boulanger and J. Brand and C. Brunt and M. Burton and L. Calzoletti and S. Carey and P. Caselli and R. Cesaroni and J. Cernicharo and S. Chakrabarti and A. Chrysostomou and M. Cohen and M. Compiegne and P. de Bernardis and G. de Gasperis and A. M. di Giorgio and D. Elia and F. Faustini and N. Flagey and Y. Fukui and G. A. Fuller and K. Ganga and P. Garcia-Lario and J. Glenn and P. F. Goldsmith and M. J. Griffin and M. Hoare and M. Huang and D. Ikhenaode and C. Joblin and G. Joncas and M. Juvela and J. M. Kirk and G. Lagache and J. Z. Li and T. L. Lim and S. D. Lord and M. Marengo and D. J. Marshall and S. Masi and F. Massi and M. Matsuura and V. Minier and M. A. Miville-Deschenes and L. A. Montier and L. Morgan and F. Motte and J. C. Mottram and T. G. Mueller and P. Natoli and J. Neves and L. Olmi and R. Paladini and D. Paradis and H. Parsons and N. Peretto and M. Pestalozzi and S. Pezzuto and F. Piacentini and L. Piazzo and D. Polychroni and M. Pomarès and C. C. Popescu and W. T. Reach and I. Ristorcelli and J. F. Robitaille and T. Robitaille and J. A. Rodón and A. Roy and P. Royer and D. Russeil and P. Saraceno and M. Sauvage and P. Schilke and E. Schisano and N. Schneider and F. Schuller and B. Schulz and B. Sibthorpe and H. A. Smith and M. D. Smith and L. Spinoglio and D. Stamatellos and F. Strafella and G. S. Stringfellow and E. Sturm and R. Taylor and M. A. Thompson and A. Traficante and R. J. Tuffs and G. Umana and L. Valenziano and R. Vavrek and M. Veneziani and S. Viti and C. Waelkens and D. Ward-Thompson and G. White and L. A. Wilcock and F. Wyrowski and H. W. Yorke and Q. Zhang},
journal= {arXiv preprint arXiv:1005.3317},
year = {2015}
}
Comments
A&A, accepted