Riunione Avanzamento 1ASI – Roma 11 Novembre 2008

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1SWG3: 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”

Riunione Avanzamento 1ASI – Roma 11 Novembre 2008

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2SWG3: 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 (Lbol,Tbol) 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

Riunione Avanzamento 1ASI – Roma 11 Novembre 2008

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3SWG3: Evolution of Young Stellar Objects

WarmCore

AccretingProtostar?

HotCore

Very YoungHigh MassStar

• 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

Riunione Avanzamento 1ASI – Roma 11 Novembre 2008

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4SWG3: Evolution of Young Stellar Objects

WarmCore

AccretingProtostar?

HotCore

Very YoungHigh MassStar

• 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

Riunione Avanzamento 1ASI – Roma 11 Novembre 2008

INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE

5SWG3: Evolution of Young Stellar Objects

WarmCore

AccretingProtostar?

HotCore

Very YoungHigh MassStar

• 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

Riunione Avanzamento 1ASI – Roma 11 Novembre 2008

INAF IFSI IRA OAFI OACT UNIRM1 UNIRM2 UNILE

6SWG3: Evolution of Young Stellar Objects

WarmCore

AccretingProtostar?

HotCore

Very YoungHigh MassStar

• 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

104 LO = LIRAS3 103 LO << LIRAS

LIRAS=2 104 LO

Riunione Avanzamento 1ASI – Roma 11 Novembre 2008

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7SWG3: 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 Lbol-Menv 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).