Searching for OH maser emission towards the MIPSGAL compact Galactic bubbles
arXiv:1510.00134 · doi:10.1093/mnras/stv1878
Abstract
We conducted radio observations searching for OH 18-cm maser emission from a sample of 169 unclassified MIPSGAL compact Galactic bubbles. These sources are thought to be the circumstellar envelopes of different kinds of evolved stars. Our observations were aimed at shedding light on the nature of MIPSGAL bubbles, since their characterisation is a fundamental aid for the development of accurate physical models of stellar and Galaxy evolution. The maser emission is observatively linked to the last stages of the life of low- and intermediate-mass stars, which may constitute a significant fraction of the MIPSGAL bubbles. In particular OH masers are usually observed towards post-AGB stars. Our observations were performed with the Green Bank Telescope and, for each source, produced spectra around the four OH 18-cm transitions. The observations were compared with archive interferometer data in order to exclude possible contamination from nearby sources. The main result is that the OH maser emission is not a common feature among the MIPSGAL bubbles, with only one certain detection. We conclude that among the MIPSGAL bubbles the post-AGB stars could be very rare.
References in corpus (8)
- An evolutionary catalogue of Galactic post-AGB and related objects
- SPLASH: The Southern Parkes Large-Area Survey in Hydroxyl - First Science from the Pilot Region
- First Images of R Aquarii and its Asymmetric HO Shell
- Palomar/TripleSpec observations of {\it Spitzer}/MIPSGAL~24\mic\ circumstellar shells: unveiling the nature of their central sources
- An asymmetric jet launching model for the protoplanetary nebula CRL 618
- A Radio Characterization of Galactic compact Bubbles
- Study of the extended radio emission of two supernova remnants and four planetary nebulae associated to MIPSGAL bubbles
- Spitzer/infrared spectrograph investigation of MIPSGAL 24 μm compact bubbles : Low resolution observations