Title: Massive star formation properties in the Galactic disk

Abstract:
What are the physical conditions at the earliest stage of massive star and star cluster 
formation? Is there a dependence of star formation on galactic environment?

The European missions Planck and Herschel gave us the possibility to identify the whole 
Galactic population of massive pre-star/pre-cluster forming clouds with an unbiased selection 
criteria and to establish in great detail their density and temperature structure through direct 
measurements of their thermal dust emission in the far-infrared and sub-mm wavelengths.

The Planck Early Cold Cores catalogue contains 915 reliable cold molecular cloud clump 
candidates from the first all sky catalogue of cold objects. This offers the opportunity to search 
for massive star forming clumps also in the outer Galaxy and investigate the dependence of 
massive star formation with location in the Galactic disk.

Based on the Planck catalogue cold clouds were studied with Herschel data from the Herschel 
Open Time Key Project "Herschel infrared Galactic Plane Survey (Hi-GAL)" at higher spatial 
resolution. 
Herschel PACS and SPIRE observations of the selected 50 Planck cold clumps allowed us to 
examine the structure and physical characteristics of the sources and their environment. The 
selected clouds have distances ranging from 0.5 kpc to 8 kpc, and masses from a few solar 
masses to 100000 solar masses.

Based on this diverse dataset of an unbiased sample of cold clouds, we can compare the star 
formation properties in different part of our Galaxy and set tight constraints on the early 
conditions during cloud and star formation.