SOMA: The SOFIA Massive Radio Survey. III. Radio Emission from Intermediate-mass Protostars
11 affiliations
- 1University of Wisconsin-Madison
- 2California Institute of Technology
- 3Space Science Institute
- 4National Radio Astronomy Observatory
- 5Instituto de Astrofísica de Andalucía
- 6Chalmers University of Technology
- 7Shanghai Jiao Tong University
- 8University of Virginia
- 9University of Oslo
- 10Carl Sagan Center for Research
- 11INAF-Osservatorio Astrofisico di Arcetri
Abstract
We present results from Karl G. Jansky Very Large Array radio-continuum observations of 12 intermediate-mass (IM) protostars, as part of the SOFIA Massive Star Formation Survey. Using these observations, we studied their morphology, multiplicity, and radio spectral energy distributions (SEDs). Across our target regions, we resolve multiple compact sources and report eight new detections, four of which are entirely new and four that have counterparts at other wavelengths, but are detected here for the first time at radio frequencies. Based on radio morphologies and spectral indices, we assess the nature of the detected sources, highlighting seven that display jetlike structures and spectral indices consistent with ionized jets. Combining our results with the SOMA Radio I and II results, we expand the overall sample to 29 protostars, covering a bolometric luminosity range from L bol ∼ 10 ² to 10 ⁶ L ⊙ . These sources help define a potential evolutionary sequence in the radio versus bolometric luminosity diagram. IM protostars have radio luminosities that are lower than expected from a simple power-law extrapolation from low-mass protostars. However, this result is consistent with theoretical expectations from protostellar evolution models, which show low levels of photoionization and reduced shock ionization emission due to expanded stellar radii during this phase. Overall our expanded SOMA Radio sample provides new constraints on theoretical models of massive protostellar evolution, especially the connection to ionized gas structures.
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BibTeX
@article{sequeiramurillo2026soma,
title = {{SOMA: The SOFIA Massive Radio Survey. III. Radio Emission from Intermediate-mass Protostars}},
author = {Francisco Sequeira-Murillo and Viviana Rosero and Joshua Marvil and Ruben Fedriani and Yichen Zhang and Prasanta Gorai and James M. De Buizer and Maria T. Beltrán and Jonathan C. Tan},
journal = {The Astrophysical Journal},
year = {2026},
month = oct,
doi = {10.3847/1538-4357/ae95fe},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/ae95fe},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - SOMA: The SOFIA Massive Radio Survey. III. Radio Emission from Intermediate-mass Protostars
AU - Francisco Sequeira-Murillo
AU - Viviana Rosero
AU - Joshua Marvil
AU - Ruben Fedriani
AU - Yichen Zhang
AU - Prasanta Gorai
AU - James M. De Buizer
AU - Maria T. Beltrán
AU - Jonathan C. Tan
PY - 2026
DA - 2026/10/13
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/ae95fe
UR - https://iopscience.iop.org/article/10.3847/1538-4357/ae95fe
AB - We present results from Karl G. Jansky Very Large Array radio-continuum observations of 12 intermediate-mass (IM) protostars, as part of the SOFIA Massive Star Formation Survey. Using these observations, we studied their morphology, multiplicity, and radio spectral energy distributions (SEDs). Across our target regions, we resolve multiple compact sources and report eight new detections, four of which are entirely new and four that have counterparts at other wavelengths, but are detected here for the first time at radio frequencies. Based on radio morphologies and spectral indices, we assess the nature of the detected sources, highlighting seven that display jetlike structures and spectral indices consistent with ionized jets. Combining our results with the SOMA Radio I and II results, we expand the overall sample to 29 protostars, covering a bolometric luminosity range from L bol ∼ 10 ² to 10 ⁶ L ⊙ . These sources help define a potential evolutionary sequence in the radio versus bolometric luminosity diagram. IM protostars have radio luminosities that are lower than expected from a simple power-law extrapolation from low-mass protostars. However, this result is consistent with theoretical expectations from protostellar evolution models, which show low levels of photoionization and reduced shock ionization emission due to expanded stellar radii during this phase. Overall our expanded SOMA Radio sample provides new constraints on theoretical models of massive protostellar evolution, especially the connection to ionized gas structures.
SN - 0004-637X
SN - 1538-4357
ER -