Periodic 6.7 GHz $\mathrm{C}{\mathrm{H}}_3\mathrm{OH}$ maser emission in G353.273+0.641: First candidate for a pulsating high-mass protostar

Abstract

We report on the periodic flux variations in the 6.7 GHz $\mathrm{C}{\mathrm{H}}_3\mathrm{OH}$ maser associated with the high-mass protostar G353.273+0.641, based on 13 yr of monitoring mainly by the Hitachi 32 m telescope. We identified a periodicity of 309 days based on a nearly complete light curve, with 833 epochs every few days. A strong correlation is found between the maser and the mid-infrared fluxes at 3.4 and 4.6 $\mu$m observed by NEOWISE during these periods, suggesting that the maser emission responds to variations in the protostellar luminosity. The average profile of the maser light curve is asymmetric and shows a steep drop in intensity just before the brightening, resembling that of some pulsating variable stars. Assuming a protostellar pulsation as the origin of maser periodicity, the observed period implies a cool and highly bloated, red supergiant-like structure. Such a bloated structure is consistent with a theoretical model of protostellar evolution under high accretion rates. The inferred protostellar parameters are broadly consistent with the theoretical model of pulsational instability during the early phase of high-mass star formation. However, a periodic accretion scenario caused by an unresolved compact protobinary cannot be completely ruled out. Several irregular peaks that deviate from the periodicity may result from episodic accretion phenomena or jet-launching events independent of the protostellar pulsation. Extremely high-resolution imaging with next-generation interferometers such as the ngVLA will provide a conclusive test for both the protostellar pulsation and the binary accretion scenarios.

14 pages, 10 figures

References in corpus (23)

• Array Programming with NumPy
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Initial Performance of the NEOWISE Reactivation Mission
• An extraordinary outburst in the massive protostellar system NGC6334I-MM1: quadrupling of the millimeter continuum
• Disk-Driven Rotating Bipolar Outflow in Orion Source I
• Water maser variability over 20 years in a large sample of star-forming regions: the complete database
• On the Class II Methanol Maser Periodic Variability due to the Rotating Spiral Shocks in the Gaps of Disks Around Young Binary Stars
• Orion Source I's disk is salty
• New Periodic 6.7 GHz Class II Methanol Maser Associated with G358.460-0.391
• The first bird's-eye view of a gravitationally unstable accretion disk in high-mass star formation
• A Keplerian disk with a four-arm spiral birthing an episodically accreting high-mass protostar
• Dynamics of a Massive Binary at Birth
• On the episodic excursions of massive protostars in the Hertzsprung-Russell diagram
• Shock breakouts from red supergiants: analytical and numerical predictions
• The environment of the strongest galactic methanol maser
• Salt-bearing disk candidates around high-mass young stellar objects
• Accelerating a water maser face-on jet from a high mass young stellar object
• Accretion Burst Echoes as Probes of Protostellar Environments and Episodic Mass Assembly
• The Evolutionary Status of Protostellar Clumps Hosting Class II Methanol Masers
• A Face-on Accretion System in High-Mass Star-Formation: Possible Dusty Infall Streams within 100 AU
• A highly variable methanol maser in G111.256-0.770
• Mid-Infrared and Maser Flux Variability Correlation in Massive Young Stellar Object G036.70+00.09
• A kinematic study of the disc-outflow system around a high-mass protostar G59.783+0.065 probed by methanol and water masers

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