1. Riunione Avanzamento 1 ASI – Roma 11 Novembre 2008 INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE 1 SWG3: Evolution of Young Stellar Objects Goals Establish an evolutionary sequence for Massive YSOs SED shapes, bolometric luminosities and temperatures Synergy with IRDCs and Molecular Clouds Derive the timeline for the massive star formation phases Invert object counts in the various phases Measure the Star Formation Rate across the Galaxy Synergy with Global Galactic SF Evolution of YSOs

2. Riunione Avanzamento 1 ASI – Roma 11 Novembre 2008 INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE 2 SWG3: Evolution of Young Stellar Objects Source Classification Tools SEDs automatic building from Hi-GAL and ancillary data (ATLASGAL, Bolocam, JPS, GLIMPSE, MIPSGAL) Distances and luminosities, mainly kinematical distances SED model grids and (L bol,T bol ) diagnostics Automatic source Classification (expert systems?) Pathfinder Samples Start developing the tools on samples of well characterized objects IRDCs, warm cores/protostars, Hot Cores, well characterized HII Massive complementary mm and radio spectroscopy program to provide ancillary data Distances and Bolometric Luminosities Kinematic (mols & HI), association with known sources, maser parallaxes Methods & Tools

3. Riunione Avanzamento 1 ASI – Roma 11 Novembre 2008 INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE 3 SWG3: Evolution of Young Stellar Objects Warm Core Accreting Protostar? Hot Core Very Young High Mass Star Tracers: Warm Dust, Cold Dust, Free-Free Key: Identify sources in various evolutionary stages in complex regions IRAS 23385+6053 IRAS 20126+4104 Source Classification: Example

4. Riunione Avanzamento 1 ASI – Roma 11 Novembre 2008 INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE 4 SWG3: Evolution of Young Stellar Objects Warm Core Accreting Protostar? Hot Core Very Young High Mass Star Tracers: Warm Dust, Cold Dust, Free-Free Key: Identify sources in various evolutionary stages in complex regions IRAS 23385+6053 IRAS 20126+4104 Source Classification: Example

5. Riunione Avanzamento 1 ASI – Roma 11 Novembre 2008 INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE 5 SWG3: Evolution of Young Stellar Objects Warm Core Accreting Protostar? Hot Core Very Young High Mass Star Tracers: Warm Dust, Cold Dust, Free-Free Key: Identify sources in various evolutionary stages in complex regions IRAS 23385+6053 IRAS 20126+4104 Source Classification: Example

6. Riunione Avanzamento 1 ASI – Roma 11 Novembre 2008 INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE 6 SWG3: Evolution of Young Stellar Objects Warm Core Accreting Protostar? Hot Core Very Young High Mass Star Tracers: Warm Dust, Cold Dust, Free-Free Key: Identify sources in various evolutionary stages in complex regions IRAS 23385+6053 IRAS 20126+4104 Source Classification: Example 10 4 L O = L IRAS 3 10 3 L O << L IRAS L IRAS =2 10 4 L O

7. Riunione Avanzamento 1 ASI – Roma 11 Novembre 2008 INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE 7 SWG3: Evolution of Young Stellar Objects Diagnostic Diagram: Example The bolometric luminosity and the circumstellar mass are important age indicators for YSOs. Sources in different evolutionary stages occupy different regions in a L bol - M env diagram. Simple models reproduce (Molinari et al. 2008) the YSOs evolutionary path from pre-ZAMS ( Class 0) through UCHII ( Class I) to Ae-Be ( Class II).