Accurate water maser positions from HOPS

We report on high spatial resolution water maser observations, using the Australia Telescope Compact Array, towards water maser sites previously identified in the H2O southern Galactic Plane Survey (HOPS). Of the 540 masers identified in the single-dish observations of Walsh et al., we detect emissi...

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Main Authors: Walsh, Andrew, Purcell, C., Longmore, S., Breen, S., Green, A., Harvey-Smith, L., Jordan, C., Macpherson, C.
Format: Journal Article
Published: Oxford University Press 2014
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/24329
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author Walsh, Andrew
Purcell, C.
Longmore, S.
Breen, S.
Green, A.
Harvey-Smith, L.
Jordan, C.
Macpherson, C.
author_facet Walsh, Andrew
Purcell, C.
Longmore, S.
Breen, S.
Green, A.
Harvey-Smith, L.
Jordan, C.
Macpherson, C.
author_sort Walsh, Andrew
building Curtin Institutional Repository
collection Online Access
description We report on high spatial resolution water maser observations, using the Australia Telescope Compact Array, towards water maser sites previously identified in the H2O southern Galactic Plane Survey (HOPS). Of the 540 masers identified in the single-dish observations of Walsh et al., we detect emission in all but 31 fields. We report on 2790 spectral features (maser spots), with brightnesses ranging from 0.06 to 576 Jy and with velocities ranging from -238.5 to +300.5 km s-1. These spectral features are grouped into 631 maser sites. We have compared the positions of these sites to the literature to associate the sites with astrophysical objects. We identify 433 (69 percent) with star formation, 121 (19 percent) with evolved stars and 77 (12 percent) as unknown. We find that maser sites associated with evolved stars tend to have more maser spots and have smaller angular sizes than those associated with star formation. We present evidence that maser sites associated with evolved stars show an increased likelihood of having a velocity range between 15 and 35?km?s-1 compared to other maser sites. Of the 31 non-detections, we conclude they were not detected due to intrinsic variability and confirm previous results showing that such variable masers tend to be weaker and have simpler spectra with fewer peaks.
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spelling curtin-20.500.11937-243292023-02-22T06:24:21Z Accurate water maser positions from HOPS Walsh, Andrew Purcell, C. Longmore, S. Breen, S. Green, A. Harvey-Smith, L. Jordan, C. Macpherson, C. ISM: molecules masers stars: formation We report on high spatial resolution water maser observations, using the Australia Telescope Compact Array, towards water maser sites previously identified in the H2O southern Galactic Plane Survey (HOPS). Of the 540 masers identified in the single-dish observations of Walsh et al., we detect emission in all but 31 fields. We report on 2790 spectral features (maser spots), with brightnesses ranging from 0.06 to 576 Jy and with velocities ranging from -238.5 to +300.5 km s-1. These spectral features are grouped into 631 maser sites. We have compared the positions of these sites to the literature to associate the sites with astrophysical objects. We identify 433 (69 percent) with star formation, 121 (19 percent) with evolved stars and 77 (12 percent) as unknown. We find that maser sites associated with evolved stars tend to have more maser spots and have smaller angular sizes than those associated with star formation. We present evidence that maser sites associated with evolved stars show an increased likelihood of having a velocity range between 15 and 35?km?s-1 compared to other maser sites. Of the 31 non-detections, we conclude they were not detected due to intrinsic variability and confirm previous results showing that such variable masers tend to be weaker and have simpler spectra with fewer peaks. 2014 Journal Article http://hdl.handle.net/20.500.11937/24329 10.1093/mnras/stu989 Oxford University Press unknown
spellingShingle ISM: molecules
masers
stars: formation
Walsh, Andrew
Purcell, C.
Longmore, S.
Breen, S.
Green, A.
Harvey-Smith, L.
Jordan, C.
Macpherson, C.
Accurate water maser positions from HOPS
title Accurate water maser positions from HOPS
title_full Accurate water maser positions from HOPS
title_fullStr Accurate water maser positions from HOPS
title_full_unstemmed Accurate water maser positions from HOPS
title_short Accurate water maser positions from HOPS
title_sort accurate water maser positions from hops
topic ISM: molecules
masers
stars: formation
url http://hdl.handle.net/20.500.11937/24329