The Standard Model of Low-Mass Star Formation Applied to Massive Stars Multi-wavelength Modelling

1. Rotationally flattened infalling envelope The Standard Model of Low-Mass Star Formation Applied to Massive StarsMulti-wavelength Modelling Katharine Johnston Collaborators: Eric Keto (CfA) Thomas Robitaille (CfA) Kenny Wood (Univ. of St Andrews) Debra Shepherd (NRAO) Katharine Johnston (CfA, University of St Andrews) September 3, 2014

2. Two Luminous Embedded Accreting Stars IRAS 20126+4104 (1.3x104 Lsun) Cessaroni et al. 2005 Qiu et al. 2008 Cessaroni et al. 1997 AFGL 2591 (2x104 Lsun) … also see poster by K.-S. Wang, no 34 van der Tak et al. 2006 Hasegawa et al. 1995

3. M M M M M M M M M M M Searching for the Best Fitting Model:The Genetic Algorithm Start with pool of models: Models selected for “evolution” depending on their 2 Model with parameters: M*, Menv, Renv, cav, cav, inclination, Mdisk, Rdisk, Mdisk . . mutation M Fit each model to data (SED+images) M crossing 2 M IRAS 20126+4104 AFGL 2591 The SEDs: envelope plus disk envelope without disk

4. Observed and Model Images IRAS 20126+4104 Observed With disk model No disk model AFGL 2591 With disk model Observed No disk model

5. How well constrained are the parameters? With disk model AFGL 2591

6. Ionizing the Geometries 1) Found ionization equilibrium in geometry gives ionized outflow walls 2) Used ray tracing code to “observe” source 3) Compare convolved image to that observed 4) Ionized geometry (HII region)does not fit observations also require jets! AFGL 2591

7. Summary • Modelling of two massive embedded protostars using “low mass” YSO geometries • Using genetic algorithm to find best fit • Fit both the SEDs and images • Can find how uncertain model properties are • Ionized geometries found from SED modelling require other mechanism, such as jets Katharine Johnston (CfA, University of St Andrews) September 3, 2014

9. IRAS 20126+4104

10. AFGL 2591