Home All issues Volume 366 / No 2 (February I 2001) A&A, 366 2 (2001) 481-489 Abstract
Volume 366, Number 2, February I 2001
Extragalactic astronomy
The ATCA/VLA OH 1612 MHz survey*,**
III. Observations of the Northern Galactic Plane
M. N. Sevenster1, H. J. van Langevelde2, R. A. Moody1, J. M. Chapman3, H. J. Habing4 and N. E. B. Killeen3
1 MSSSO/RSAA, Cotter Road, Weston ACT 2611, Australia
2 Joint Institute for VLBI in Europe, Postbus 2, 7990 AA Dwingeloo, The Netherlands
3 Australia Telescope National Facility, PO Box 76, Epping NSW 1710, Australia
4 Sterrewacht Leiden, PO Box 9513, 2300 RA Leiden, The Netherlands
Corresponding author: M. Sevenster, msevenst@mso.anu.edu.au
Accepted: 9 November 2000
We present observations of the region between and , in the OH 1612.231 MHz line, taken from 1993 to 1995 with NRAO's Very Large Array (VLA). These observations are the last part of a larger survey, covering and , with the Australia Telescope Compact Array (ATCA) and the VLA. The region was systematically observed on a grid in ( ) and the resulting coverage was 92% , with 965 pointings. We found 286 OH-masing objects, 161 of which are new detections and 207 have reliable IRAS point-source identifications. The outflow velocity was determined for 276 sources. A total of 766 sources were detected in the combined ATCA/VLA survey, of which 29 were detected in two regions of the survey. In this article we analyse the data statistically and give identifications with known sources where possible. The "efficiency"of this VLA survey is 75% of that of the ATCA Bulge survey. This efficiency was determined by comparing the detections in the region where the two surveys overlap. The completeness-and error characteristics are similar, though less homogeneous, except for the much larger errors in the flux densities. The relatively large surface number density found in the northern disk, suggests that we can see the Bar extending to higher longitudes on this side of the galactic Centre.
Key words: surveys / techniques: image processing / stars: AGB and post AGB / radio lines: stars / galaxy: stellar content
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
Figure 10 is only available in electronic form at http://www.edpsciences.org
The ATCA/VLA OH 1612 MHz survey. I. Observations of the galactic bulge Region
Astron. Astrophys. Suppl. Ser. 122, 79-93 (1997)
The ATCA/VLA OH 1612 MHz survey — II. Observations of the galactic Disk region
Astron. Astrophys. Suppl. Ser. 124, 509-515 (1997)
A new sample of OH/IR stars in the Galactic center
Radio and IR study of the massive star-forming region IRAS 16353−4636
An updated catalog of OH-maser-emitting planetary nebulae