Star forma)on in the Galaxy with Herschel Michele Pestalozzi, INAF – IAPS, Rome on behalf of the HiGAL team P.I. is Sergio Molinari
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Star forma)on in the Galaxy with Herschel
Michele Pestalozzi, INAF – IAPS, Rome on behalf of the Hi-‐GAL team
P.I. is Sergio Molinari
One-‐slide-‐data-‐processing…
The Universe Explored by Herschel, ESTEC, October 2013
2009-‐2011 Mapmaking
From Romagal to Unimap
164 2ox2o )les in all 5 Herschel bands
2011-‐2013 Photometry
CuTEx on single )les, band per band
2nd-‐deriva)ve, Gaussian photometry
2013
Catalogues Single-‐λ cats, bandmerging, filtering, distance ass., SED fit Few 105 objects with physical proper)es
pre-‐ and protostellar labelling: based on 70µm data
Traficante et al. 2010 Piazzo et al. 2013
Molinari et al. 2010 Elia et al. 2013, +others
Physical significance DISTANCES
The Universe Explored by Herschel, ESTEC, October 2013
Based on CO cubes (NANTEN + GRS), ex)nc)on and associa)on with sources with known distances Russeil et al. 2011
What are these objects?
• Hi-‐GAL detects clumps, not cores – Sizes of the order of 0.1 pc
• Clumps contain “many” objects… – Classifica)on is difficult
• SFR and SFE: number coun)ng Hi-‐GAL sources has to pass through models
• But there are a lot of them…!
The Universe Explored by Herschel, ESTEC, October 2013
Distance independent quan))es
The Universe Explored by Herschel, ESTEC, October 2013
Pestalozzi et al. 2013, in prep
Physical significance
The Universe Explored by Herschel, ESTEC, October 2013
Pestalozzi et al. 2013, in prep
Evolu)on – comparison with models
The Universe Explored by Herschel, ESTEC, October 2013
Pestalozzi et al. 2013, in prep Molinari et al. 2008
The Scutum-‐Crux arm
The Universe Explored by Herschel, ESTEC, October 2013 Pestalozzi et al. 2014, in prep
What happens in the wake?
The Universe Explored by Herschel, ESTEC, October 2013
PRE/(PRE+PROTO)
0.6925 0.6749 0.7452
Pestalozzi et al. 2014, in prep
The scenario…
• Material is assembled in the wake of a spiral wave – Physical condi)ons of the gas in the wakes? – Turbulence, colliding flows, filamentary structures,…
• The spiral wave approaches MC and “triggers” SF
See e.g. Moore et al. 2012, Eden et al. 2013, Dobbs 2013, …
The Universe Explored by Herschel, ESTEC, October 2013
Spiral pakern – stars & gas
The Universe Explored by Herschel, ESTEC, October 2013
Conclusions
• Hi-‐GAL delivers solid sta)s)cal grounds to study SF globally in the Galaxy
• Hi-‐GAL allows precise recogni)on of evolu)onary stages
• If SF is related to the spiral arm structure, then its study can give hints on the ini)al condi)ons for SF
The Universe Explored by Herschel, ESTEC, October 2013
Thank you!
The Universe Explored by Herschel, ESTEC, October 2013
P.I. Sergio Molinari and the Hi-‐GAL steering group, Davide Elia, Eugenio Schisano, Stefano Pezzuto, Kazy Rygl, Gemma Bousquet, Danae Polychroni, Alessio Traficante, Marcella Veneziani Joe Mokram, Delphine Russeil
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