The SOFIA Massive (SOMA) Star Formation Survey. IV. Isolated Protostars
Journal article, 2023

We present similar to 10-40 mu m SOFIA-FORCAST images of 11 isolated protostars as part of the SOFIA Massive (SOMA) Star Formation Survey, with this morphological classification based on 37 mu m imaging. We develop an automated method to define source aperture size using the gradient of its background-subtracted enclosed flux and apply this to build spectral energy distributions (SEDs). We fit the SEDs with radiative transfer models, developed within the framework of turbulent core accretion (TCA) theory, to estimate key protostellar properties. Here, we release the sedcreator python package that carries out these methods. The SEDs are generally well fitted by the TCA models, from which we infer initial core masses M ( c ) ranging from 20-430 M (circle dot), clump mass surface densities sigma(cl) similar to 0.3-1.7 g cm(-2), and current protostellar masses m (*) similar to 3-50 M (circle dot). From a uniform analysis of the 40 sources in the full SOMA survey to date, we find that massive protostars form across a wide range of clump mass surface density environments, placing constraints on theories that predict a minimum threshold sigma(cl) for massive star formation. However, the upper end of the m (*)-sigma(cl) distribution follows trends predicted by models of internal protostellar feedback that find greater star formation efficiency in higher sigma(cl) conditions. We also investigate protostellar far-IR variability by comparison with IRAS data, finding no significant variation over an similar to 40 yr baseline.

Author

Rubén Fedriani

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Jonathan Tan

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Zoie Telkamp

University of Virginia

Yichen Zhang

RIKEN

University of Virginia

Yao-Lun Yang

University of Virginia

RIKEN

Mengyao Liu

University of Virginia

James M. De Buizer

NASA Ames Research Center

Chi Yan Law

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Maria T. Beltran

Istituto nazionale di astrofisica (INAF)

Viviana Rosero

National Radio Astronomy Observatory Socorro

Tanaka

University of Colorado at Boulder

National Institutes of Natural Sciences

Giuliana Cosentino

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Prasanta Gorai

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Juan Pablo Farias Osses

Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics

Jan E. Staff

University of The Virgin Islands

Barbara Whitney

Space Science Institute

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 942 1 7

Subject Categories

Astronomy, Astrophysics and Cosmology

DOI

10.3847/1538-4357/aca4cf

More information

Latest update

1/27/2023