do protostellar luminosities imply episodic accretion?
DESCRIPTION
Do Protostellar Luminosities Imply Episodic Accretion?. Oort 2014 Workshop Tuesday, May 13, 2014. Mike Dunham, SMA Fellow, CfA. Protostellar Accretion. m , m_dot not directly observable Luminosity is indirect tracer of m_dot Constrain accretion theories? - PowerPoint PPT PresentationTRANSCRIPT
Do Protostellar Luminosities Imply Episodic Accretion?
Oort 2014 WorkshopTuesday, May 13, 2014
Mike Dunham, SMA Fellow, CfA
Protostellar Accretion
• m, m_dot not directly observable
• Luminosity is indirect tracer of m_dot
• Constrain accretion theories?
• Small, biased samples; incompletely sampled SEDs
Dunham et al. (2014), credit to W. Fischer
Protostellar Luminosities
Protostellar Luminosities
Dunham et al. (2014), credit to W. Fischer
Protostellar Luminosities
Kenyon et al. (1990, 1994); Kenyon & Hartmann (1995); Dunham et al. (2013)
Protostellar Luminosities
Kenyon et al. (1990, 1994); Kenyon & Hartmann (1995)Dunham et al. (2010a), Young & Evans (2005)
7
Protostellar Luminosities
Dunham et al. (2014), credit to W. Fischer
Variable/Episodic Accretion?
Variable/Episodic Accretion: Does It Work?Protostellar Accretion
Variable/Episodic Accretion: Does It Work?
Dunham et al. (2010a)
Protostellar Accretion
Vorobyov & Basu (2005, 2006, 2010)Dunham & Vorobyov (2012)
Protostellar Accretion
Variable/Episodic Accretion: Does It Work?
Protostellar Accretion
Dunham et al. (2014), credit to S. Offner(Dunham & Vorobyov 2012; McKee & Offner (2010); Offner & McKee 2011; Myers 2009-2014)
Mass-dependent accretion can also workRelative importance of stochastic vs. secular processes?
Comments from the skeptic
Episodic Accretion
Does the Variability Matter?
Vorobyov & Basu (2005, 2006, 2010)Dunham & Vorobyov (2012)
Episodic Accretion
Is the IMF Weighting Correct?Are relatively high-mass stars missing?
Vorobyov & Basu (2005, 2006, 2010)Dunham & Vorobyov (2012)
Episodic Accretion
Are the Disks Realistic?
Vorobyov & Basu (2005, 2006, 2010)Dunham, Vorobyov, & Arce (2014), submitted
Mass-Dependent Accretion
Comparing Apples and Oranges?
Are we comparing to the correct observed distribution?
Kryukova et al. (2012); Dunham et al. (2013)
Core Association(Dunham et al. 2013)
IR Colors(Kryukova et al. 2012)
• Deeper dense core surveys
• Surveys for dense gas
• Proper motion studies
Prospects for Resolution
Refine the sample of protostars and luminosity measurements
(Relatively simple to do in the near future)
Make sure modelers and observers are comparing the same quantities
(Best way to do this?)
Compare to more than just luminosity distribution
(BLT distribution, Class 0 vs. I lifetimes and luminosity distributions, disk masses, protostellar masses [eventually], …)
Constrain the frequency, timescales and amplitudes of variability
Future Directions