OH maser emission in the THOR survey of the northern Milky Way

Abstract

Context: OH masers trace diverse physical processes, from the expanding envelopes around evolved stars to star-forming regions or supernovae remnants. Aims: We identify the ground-state OH masers at 18cm wavelength in the area covered by ``The HI/OH/Recombination line survey of the Milky Way (THOR)''. We present a catalogue of all OH maser features and their possible associated environments. Methods: The THOR survey covers longitude and latitude ranges of 14.3<l<66.8 and b<1.25 deg. All OH ground state lines at 1612, 1665, 1667 and 1720MHz have been observed, employing the Very Large Array. The spatial resolution of the data varies between 12.5'' and 19'', the spectral resolution is 1.5km/s, and the rms sensitivity of the data is ~10mJy/beam per channel. Results: We identify 1585 individual maser spots distributed over 807 maser sites. Based on different criteria from spectral profiles to literature comparison, we try to associate the maser sites with astrophysical source types. Approximately 51\% of the sites exhibit the double-horned 1612MHz spectra typically emitted from the expanding shells of evolved stars. The separations of the two main velocity features of the expanding shells typically vary between 22 and 38km/s. In addition to this, at least 20% of the maser sites are associated with star-forming regions. While the largest fraction of 1720MHz maser spots (21 out of 53) is associated with supernova remnants, a significant fraction of the 1720MHz maser spots (17) are also associated with star-forming regions. We present comparisons to the thermal 13CO(1-0) emission as well as to other surveys of class II CH3OH and H2O maser emission. The catalogue attempts to present associations to astrophysical sources where available, and the full catalogue is available in electronic form.

arXiv commentThe main paper contains 13 pages and 7 pages. However, the full paper with appendix where all maser sites are shown and also the full catalogue is presented can be found at http://www.mpia.de/thor/Data_%26_Publications.html

References in corpus (52)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• The SIMBAD astronomical database
• The Milky Way in Molecular Clouds: A New Complete CO Survey
• GLIMPSE: I. A SIRTF Legacy Project to Map the Inner Galaxy
• ATLASGAL - The APEX Telescope Large Area Survey of the Galaxy at 870 microns
• The Boston University-Five College Radio Astronomy Observatory Galactic Ring Survey
• The H.E.S.S. Galactic plane survey
• The VLA Galactic Plane Survey
• The SCUBA Legacy Catalogue: Continuum Objects Detected by SCUBA
• The initial conditions of stellar protocluster formation. I. A catalogue of Spitzer dark clouds
• A Parallax-based Distance Estimator for Spiral Arm Sources
• The 6-GHz methanol multibeam maser catalogue I: Galactic Centre region, longitudes 345 to 6
• Hi-GAL, the Herschel infrared Galactic Plane Survey: photometric maps and compact source catalogues. First data release for Inner Milky Way: +68°> l > -70°
• The Bolocam Galactic Plane Survey -- II. Catalog of the Image Data
• A general catalogue of 6.7 GHz methanol masers. I: data
• From Massive Protostars to a Giant HII Region: Submillimeter Imaging of the Galactic Mini-starburst W43
• The H_2O southern Galactic Plane Survey (HOPS): I. Techniques and H_2O maser data
• The Co-ordinated Radio and Infrared Survey for High Mass Star Formation (The CORNISH Survey) - I. Survey Design
• The 6-GHz Multibeam Maser Survey I. Techniques
• The RMS Survey: 6 cm continuum VLA observations towards candidate massive YSOs in the northern hemisphere
• 12.2-GHz methanol masers associated with 1.2-mm dust clumps: Quantifying high-mass star formation evolutionary schemes
• The 6-GHz methanol multibeam maser catalogue II: Galactic longitudes 6 to 20
• Millimetre continuum observations of southern massive star formation regions. I. SIMBA observations of cold cores
• OH 1720 MHz Masers in Supernova Remnants --- C-Shock Indicators
• SEDIGISM: Structure, excitation, and dynamics of the inner Galactic interstellar medium
• Duchamp: a 3D source finder for spectral-line data
• CHIMPS: the ${}^{13}$CO/C${}^{18}$O (J=3-2) Heterodyne Inner Milky Way Plane Survey
• A SCUBA imaging survey of ultracompact HII regions: The environments of massive star formation
• The ATCA/VLA OH 1612 MHz survey. III. Northern Galactic Plane
• Interstellar Hydroxyl Masers in the Galaxy. II. Zeeman Pairs and the Galactic Magnetic Field
• Accurate water maser positions from HOPS
• H2O Maser Observations of Candidate Post-AGB Stars and Discovery of Three High-velocity Water Sources
• THOR - The HI, OH, Recombination Line Survey of the Milky Way - The pilot study: HI observations of the giant molecular cloud W43
• SiO Maser Survey of IRAS Sources in the Inner Galactic Disk
• SPLASH: The Southern Parkes Large-Area Survey in Hydroxyl - First Science from the Pilot Region
• The Sizes of 1720 MHz OH Masers: VLBA and MERLIN Observations of the Supernova Remnants W44 and W28
• Young massive stars in the ISOGAL survey II. The catalogue of bright YSO candidates
• H2O Southern Galactic Plane Survey (HOPS): Paper III - Properties of Dense Molecular Gas across the Inner Milky Way
• Radio continuum emission in the northern Galactic plane: Sources and spectral indices from the THOR survey
• Parkes full polarization spectra of OH masers - I. Galactic longitudes 350 through the Galactic Centre to 41
• A Hi-GAL study of the high-mass star-forming region G29.96-0.02
• MALT-45: A 7 mm survey of the southern Galaxy - I. Techniques and spectral line data
• Feedback in W49A diagnosed with radio recombination lines and models
• OH absorption in the first quadrant of the Milky Way as seen by THOR
• Accurate OH maser positions from the SPLASH pilot region
• A Survey for Hydroxyl in the THOR Pilot Region around W43
• MALT-45: A 7mm survey of the southern Galaxy - II. ATCA follow-up observations of 44GHz class I methanol masers
• Search for radiative pumping lines of OH masers: I. The 34.6um absorption line towards 1612 MHz OH maser sources
• The spatiokinematical structure of H_2O and OH masers in the "water fountain" source IRAS 18460-0151
• The 6-GHz multibeam maser survey III: comparison between the MMB and HOPS
• Maser Source Finding Methods in HOPS
• Pilot Observations for MALT-45: A Galactic Plane Survey at 7mm

Cited by in corpus (17)

• Revisiting the distance, environment and supernova properties of SNR G57.2+0.8 that hosts SGR 1935+2154
• The HI/OH/Recombination line survey of the inner Milky Way (THOR): data release 2 and HI overview
• The history of dynamics and stellar feedback revealed by the HI filamentary structure in the disk of the Milky Way
• Using Interstellar Clouds to Search for Galactic PeVatrons: Gamma-ray Signatures from Supernova Remnants
• ATLASGAL -- Relationship between dense star forming clumps and interstellar masers
• In search of infall motion in molecular clumps III: HCO+ (1-0) and H13CO+ (1-0) mapping observations toward the confirmed infall sources
• The parallax and 3D kinematics of water masers in the massive star-forming region G034.43+0.24
• MAGMO: Polarimetry of 1720-MHz OH Masers towards Southern Star Forming Regions
• Modelling cosmic masers in C-type shock waves -- the coexistence of Class I CH3OH and 1720 MHz OH masers
• SCOTCH Search for Clandestine Optically Thick Compact HII regions II
• A search for the OH 6035 MHz line in high-mass star-forming regions
• Discovery of widespread non-metastable ammonia masers in the Milky Way
• Excited Hydroxyl Outflow in the High-Mass Star-Forming Region G34.26+0.15
• W49N MCN-a: a disk accreting massive protostar embedded in an early-phase hot molecular core
• Metrewave Galactic Plane with the uGMRT (MeGaPluG) Survey: Lessons from the Pilot Study
• Collisional Pumping of OH Masers near Supernova Remnants
• The Gaia Catalogue of Galactic AGB Stars