Class I methanol masers in low-mass star formation regions

Abstract

Four Class I maser sources were detected at 44, 84, and 95 GHz toward chemically rich outflows in the regions of low-mass star formation NGC 1333I4A, NGC 1333I2A, HH25, and L1157. One more maser was found at 36 GHz toward a similar outflow, NGC 2023. Flux densities of the newly detected masers are no more than 18 Jy, being much lower than those of strong masers in regions of high-mass star formation. The brightness temperatures of the strongest peaks in NGC 1333I4A, HH25, and L1157 at 44 GHz are higher than 2000 K, whereas that of the peak in NGC 1333I2A is only 176 K. However, rotational diagram analysis showed that the latter source is also a maser. The main properties of the newly detected masers are similar to those of Class I methanol masers in regions of massive star formation. The former masers are likely to be an extension of the latter maser population toward low luminosities of both the masers and the corresponding YSOs.

5 pages, 1 figure, Proc. IAU Symp. 287 "Cosmic Masers: from OH to H0". LSR velocities of the HH25 masers, which are presented in Table 1, are corrected

References in corpus (3)

• Theory of Star Formation
• A Flattened Protostellar Envelope in Absorption around L1157
• The clumpy structure of the chemically active L1157 outflow

Cited by in corpus (10)

• Southern class I methanol masers at 36 and 44 GHz
• Online Database of Class I Methanol Masers
• Class I Methanol (CH${}_3$OH) Maser Conditions near Supernova Remnants
• Simultaneous Survey of Water and Class I Methanol Masers toward Red MSX Sources
• Modelling CH${}_3$OH masers: Sobolev approximation and accelerated lambda iteration method
• 44 GHz methanol masers: Observations toward 95 GHz methanol masers
• The physical parameters of clumps associated with class I methanol masers
• First detection of the $J_{-1}\to (J-$ 1)${}_0-E$ methanol maser transitions at $J=7$ and $10$
• Class I methanol masers in low-mass star formation regions
• Simultaneous 22 GHz Water and 44 GHz Methanol Masers Survey of Ultracompact HII Regions