Unveiling the First O-Type Bloated Star Candidate through ALMA and EVLA Observations

Fuente: arXiv
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Main Authors: Pandey, Rakesh, Palau, Aina, Sánchez-Monge, Alvaro, Sahai, Raghvendra, Kuiper, Rolf, Rodríguez, Luis F., Contreras, Carmen Sánchez, Sharma, Saurabh
Format: Preprint
Published: 2026
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author Pandey, Rakesh
Palau, Aina
Sánchez-Monge, Alvaro
Sahai, Raghvendra
Kuiper, Rolf
Rodríguez, Luis F.
Contreras, Carmen Sánchez
Sharma, Saurabh
author_facet Pandey, Rakesh
Palau, Aina
Sánchez-Monge, Alvaro
Sahai, Raghvendra
Kuiper, Rolf
Rodríguez, Luis F.
Contreras, Carmen Sánchez
Sharma, Saurabh
contents We investigate the circumstellar environment of the O-type bloated star candidate IRAS 19520+2759 (I19520) using high-resolution observations from the Atacama Large Millimeter/submillimeter Array (ALMA) and the Expanded Very Large Array (EVLA). Radio continuum emission traced by the EVLA (C, K, and Q bands) exhibits a spectral index of 0.5, consistent with a thermal jet. ALMA 1.3 mm continuum map reveals a compact source coincident with the optical counterpart of I19520, likely tracing the dense core hosting the central massive young stellar object. A prominent molecular outflow in the east-west direction, along with a possible secondary outflow oriented northeast-southwest, is identified in the $^{13}\mathrm{CO}$ emission. A hot molecular core and a Keplerian disk are detected in several $\mathrm{SO}_2$ transitions. Assuming an edge-on disk geometry, the dynamical mass of the central object is estimated to be in the range of $10$-$15~M_\odot$.
format Preprint
id arxiv_https___arxiv_org_abs_2601_12336
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Unveiling the First O-Type Bloated Star Candidate through ALMA and EVLA Observations
Pandey, Rakesh
Palau, Aina
Sánchez-Monge, Alvaro
Sahai, Raghvendra
Kuiper, Rolf
Rodríguez, Luis F.
Contreras, Carmen Sánchez
Sharma, Saurabh
Solar and Stellar Astrophysics
Astrophysics of Galaxies
We investigate the circumstellar environment of the O-type bloated star candidate IRAS 19520+2759 (I19520) using high-resolution observations from the Atacama Large Millimeter/submillimeter Array (ALMA) and the Expanded Very Large Array (EVLA). Radio continuum emission traced by the EVLA (C, K, and Q bands) exhibits a spectral index of 0.5, consistent with a thermal jet. ALMA 1.3 mm continuum map reveals a compact source coincident with the optical counterpart of I19520, likely tracing the dense core hosting the central massive young stellar object. A prominent molecular outflow in the east-west direction, along with a possible secondary outflow oriented northeast-southwest, is identified in the $^{13}\mathrm{CO}$ emission. A hot molecular core and a Keplerian disk are detected in several $\mathrm{SO}_2$ transitions. Assuming an edge-on disk geometry, the dynamical mass of the central object is estimated to be in the range of $10$-$15~M_\odot$.
title Unveiling the First O-Type Bloated Star Candidate through ALMA and EVLA Observations
topic Solar and Stellar Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2601.12336