Browsing by Subject "ISM: molecules"

Now showing items 1-8 of 8

    • Detection of new methanol maser transitions associated with G358.93−0.03 

      Macleod, G.C.; Chibueze, J.O.; Sugiyama, K.; Hunter, T.R.; Quick, J. (Oxford Univ Press, 2019)
      We report the detection of new 12.178, 12.229, 20.347, and 23.121 GHz methanol masers in the massive star-forming region G358.93−0.03, which are flaring on similarly short time-scales (days) as the 6.668 GHz methanol masers ...

    • A masing event in NGC 6334I: contemporaneous flaring of hydroxyl, methanol, and water masers 

      MacLeod, G.C.; Chibueze, J.O.; Thesner, C.J.; Smits, D.P.; Goedhart, S. (Oxford Univ Press, 2018)
      As a product of the maser monitoring program with the 26 m telescope of the Hartebeesthoek Radio Astronomy Observatory (HartRAO), we present an unprecedented, contemporaneous flaring event of 10 maser transitions in hydroxyl, ...

    • NH 3 observations of the S235 star-forming region: dense gas in inter-core bridges 

      Burns, Ross A.; Chibueze, James O.; Handa, Toshihiro; Omodaka, Toshihiro; Sobolev, Andrej M. (Oxford Univ Press, 2019)
      Star formation is thought to be driven by two groups of mechanisms; spontaneous collapse and triggered collapse. Triggered star formation mechanisms further diverge into cloud–cloud collision (CCC), “collect and collapse” ...

    • NH3 observations of the S235 star-forming region: dense gas in inter-core bridges 

      Burns, Ross A.; Chibueze, James O.; Handa, Toshihiro; Omodaka, Toshihiro; Sobolev, Andrej M. (Oxford Univ Press, 2019)
      Star formation is thought to be driven by two groups of mechanisms; spontaneous collapse and triggered collapse. Triggered star formation mechanisms further diverge into cloud–cloud collision (CCC), “collect and collapse” ...

    • Periodic class II methanol masers in G9.62+0.20E 

      Van der Walt, D.J.; Goedhart, S.; Gaylard, M.J. (Oxford Univ Press, 2009)
      We present the light curves of the 6.7 and 12.2 GHz methanol masers in the star-forming region G9.62+0.20E for a time-span of more than 2600 d. The earlier reported period of 244 d is confirmed. The results of monitoring ...

    • Periodic methanol masers in G9.62+0.20E (Research note) 

      Van der Walt, D.J.; Maswanganye, J.P.; Goedhart, S.; Van den Heever, S.P.; Etoka, S. (EDP Sciences, 2016)
      A number of mechanisms for understanding the periodic class II methanol masers associated with some high-mass star forming regions have been proposed in the past. Two recent proposals by Parfenov & Sobolev (2014, MNRAS, ...

    • Periodic methanol masers: from a colliding wind binary (CWB) perspective 

      Van den Heever, S.P.; Van der Walt, D.J.; Pittard, J.M.; Hoare, M.G. (Oxford Univ Press, 2019)
      Since the discovery of periodic class II methanol masers at 6.7 and 12.2 GHz associated with high-mass star formation regions (HMSFRs), a number of possible driving mechanisms have been proposed to explain this phenomenon. ...

    • Pumping of the 4.8 GHz H2CO masers and its implications for the periodic masers in G37.55+0.20 

      Van der Walt, D.J. (EDP Sciences, 2014)
      Context. Periodic or regular flaring of class II CH3OH masers in nine high mass star forming regions is now a well established phenomenon. Amongst the nine star forming regions, G37.55+0.20 is the only case at present ...