Astronomy and Astrophysics – Astrophysics
Scientific paper
Jan 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aas...21541604f&link_type=abstract
American Astronomical Society, AAS Meeting #215, #416.04; Bulletin of the American Astronomical Society, Vol. 42, p.267
Astronomy and Astrophysics
Astrophysics
Scientific paper
This study of water maser emission from the "water fountain" pre-planetary nebula IRAS16342-3814 used 1.35 cm observations made with the Very Large Array of the National Radio Astronomy Observatory. Seven observing epochs over one year sampled an LSR velocity range of 370 km/sec (since masers are known over a range of more than 250 km/s). The wide range reveals maser spots at several different velocities, including the well-known features at extreme red-shifted ( LSR +180 km/sec) and blue-shifted ( LSR -66 km/sec) velocities, relative to the stellar velocity. Identification of maser spots over time gives a better picture of the growth, orientation, and physical nature of the bipolar outflow lobes. The data reveals maser spots at previously unreported velocities ( LSR -10 to +5 km/s). Some maser spots identified in the past are no longer seen. Masers from different velocity ranges differ in intensity by 100x. Within the year, some individual masers vary in intensity by 10x. Besides revealing growth and decline of the different masers, we hoped to observe the separation of the extremely shifted masers. Previous studies measured about 3 arcsec in breadth. The angular resolution of the VLA images was typically 0.7 - 1.2 arcseconds, and the data were imaged with 0.2 arcsec per pixel, so we expected to resolve the separation of extremely shifted masers by 15 pixels. This separation was not observed. Existing, near-simultaneous observations with the Very Large Baseline Array will be used to investigate this expected separation.
This research was performed under the National Science Foundation's Research Experience for Teachers program during the summer of 2009. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. RS and MM were funded by a Long Term Space Astrophysics award from NASA for this work
Claussen Mark
Fagrelius Eric
Morris Marita
Sahai Raghvendra
No associations
LandOfFree
VLA Monitoring of the Water Masers in the Water Fountain Nebula IRAS16342-3814 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with VLA Monitoring of the Water Masers in the Water Fountain Nebula IRAS16342-3814, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and VLA Monitoring of the Water Masers in the Water Fountain Nebula IRAS16342-3814 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-966572