Search for Collisionally Pumped 1720 MHz OH Masers in Star-forming Regions: A VLA Survey of 18 cm OH Masers toward 80 Class I Methanol Masers
Journal: The Astrophysical Journal Supplement Series
Year: 2021

Abstract Class I methanol masers (cIMMs) and 1720 MHz OH masers are believed to arise from a common collisional pumping mechanism, and both trace shocked gas regions in supernova remnants (SNRs). However, their coexistence in star formation regions (SFRs) and their association with a front of bipolar outflow (a source of shock-stimulated collisional pumping) remain unclear. To search for collisionally pumped OH(1720) masers, we conducted a Very Large Array survey of the 18 cm OH masers and conti