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Abstract We present ∼8–40μm SOFIA-FORCAST images of seven regions of “clustered” star formation as part of the SOFIA Massive Star Formation Survey. We identify a total of 34 protostar candidates and build their spectral energy distributions (SEDs). We fit these SEDs with a grid of radiative transfer models based on the turbulent core accretion (TCA) theory to derive key protostellar properties, including initial core mass,Mc, clump environment mass surface density, Σcl, and current protostellar mass,m*. We also carry out empirical graybody (GB) estimation of Σcl, which allows a case of restricted SED fitting within the TCA model grid. We also release version 2.0 of the open-source Python packagesedcreator, which is designed to automate the aperture photometry and SED building and fitting process for sources in clustered environments, where flux contamination from close neighbors typically complicates the process. Using these updated methods, SED fitting yields values ofMc∼ 30–200M⊙, Σcl,SED∼ 0.1–3 g cm−2, andm*∼ 4–50M⊙. The GB fitting yields smaller values of Σcl,GB≲ 1 g cm−2. From these results, we do not find evidence for a critical Σclneeded to form massive (≳8M⊙) stars. However, we do find tentative evidence for a dearth of the most massive (m*≳ 30M⊙) protostars in the clustered regions, suggesting a potential impact of environment on the stellar initial mass function.
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This content will become publicly available on January 15, 2027
Investigating the Role of Protostellar Variability with PRIMA Using Monte Carlo Simulations
Abstract Evidence suggests that protostellar outbursts likely play a critical role in the stellar mass assembly process, but the extent of this contribution is not well understood. Using the proposed observing program of PRIMA, a conceptual far-IR observatory (PRIMA GO Case #43 in A. Moullet et al 2023.), we examine the probe’s ability to unambiguously determine whether or not variable accretion events dominate the stellar mass assembly process (Mburst≥ 0.5M*). To do this, we construct multiple protostellar ensembles using Herschel 70μm flux data and evolve them using a toy Monte Carlo simulation through steady-state and high-magnitude accretion events. Ensembles are observed at various epochs in the evolution process to conclude how many large-amplitude outbursts are observationally recoverable during the proposed program. Based on our synthetic observations and our simulation specifications, we determine that observing a protostellar ensemble of at least 2000 protostars using PRIMA’s proposed program is sufficient for determining the importance of protostellar outbursts in the stellar mass assembly process.
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- PAR ID:
- 10686853
- Publisher / Repository:
- The Astrophysical Journal
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 997
- Issue:
- 1
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 93
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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