Class I methanol masers in NGC253: Alcohol at the end of the bar

Abstract

We have used the Australia Telescope Compact Array (ATCA) to observe the 36.2-GHz class I methanol maser emission towards NGC253 and find that it is located at the interface between the nuclear ring and both ends of the galactic bar. This is thought to be the location of the inner Linblad resonance and we suggest that the maser emission in this region is likely due to large-scale cloud-cloud collisions. We have detected the first extragalactic 44.1-GHz class I methanol maser and find that it is associated with the 36.2-GHz maser emission. In contrast to the class I methanol masers found in Galactic star formation regions, the 44.1-GHz emission in NGC253 is two orders of magnitude weaker than the 36.2-GHz masers. Both the 36.2- and 44.1- GHz emission is orders of magnitude stronger than expected from typical high-mass star formation regions. This demonstrates that the luminous class I methanol masers observed in NGC253 are significantly different from those associated with Galactic star formation.

13 pages, 5 figures, accepted for publication in MNRAS

References in corpus (14)

• The ACS Nearby Galaxy Survey Treasury
• A 2 mm spectral line survey of the starburst galaxy NGC 253
• ALMA Reveals the Molecular Medium Fueling the Nearest Nuclear Starburst
• Class I methanol masers in the outflow of IRAS 16547-4247
• New insights on the dense molecular gas in NGC253 as traced by HCN and HCO+
• LABOCA observations of nearby, active galaxies
• The Sub-parsec Scale Radio Properties of Southern Starburst Galaxies. I. Supernova Remnants, the Supernova Rate, and the Ionised Medium in the NGC 253 Starburst
• Survey of Water and Ammonia in Nearby galaxies (SWAN): Resolved Ammonia Thermometry, Water and Methanol Masers in the Nuclear Starburst of NGC 253
• Detection of 36 GHz class I methanol maser emission towards NGCS253
• Evidence of a pure starburst nature of the nuclear region of NGC 253
• Methanol detection in M82
• Detection of a methanol megamaser in a major-merger galaxy
• Class I Methanol (CH${}_3$OH) Maser Conditions near Supernova Remnants
• The NIR structure of the barred galaxy NGC253 from VISTA

Cited by in corpus (5)

• Cloud-cloud collision as drivers of the chemical complexity in Galactic Centre molecular clouds
• Online Database of Class I Methanol Masers
• 84-GHz methanol masers, their relationship to 36-GHz methanol masers and their molecular environments
• Astrophysical constraints on the proton-to-electron mass ratio with FAST
• 36 GHz methanol lines from nearby galaxies: maser or quasi-thermal emission?