Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-26T11:44:05.275Z Has data issue: false hasContentIssue false

Intrinsic Sizes of the W3 (OH) Masers via Short Time Scale Variability

Published online by Cambridge University Press:  24 July 2012

Tanmoy Laskar
Affiliation:
Harvard University, 60 Garden St., Cambridge, MA - 02138, USA email: [email protected]
W. M. Goss
Affiliation:
National Radio Astronomy Observatory, PO Box 0, Socorro, NM - 87801, USA textitail: [email protected]
B. Ashley Zauderer
Affiliation:
Harvard University, 60 Garden St., Cambridge, MA - 02138, USA email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

We present a study of short time-scale variability of OH masers within a contiguous 15-hour Very Long Baseline Array observation of the high-mass star-forming region, W3 (OH). With an angular resolution of ~7 mas and a velocity resolution of 53 m s−1, we isolate emission from masers in the field into individual Gaussian-shaped components, each a few milliarcseconds in size. We compute dynamic spectra for individual maser features with a time resolution of 1 minute by fitting for the flux density of all sources in the field simultaneously in the uv-domain. We isolate intrinsic maser variability from interstellar scintillation and instrumental effects. We find fluctuations in the maser line shape on time scales of 5 to 20 minutes, corresponding to maser column lengths of 0.5 to 2.0 Astronomical Units.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2012

References

Baudry, A., Desmurs, J. F., Wilson, T. L., & Cohen, R. J. 1997, A&A, 325, 255Google Scholar
Caswell, J. L. & Vaile, R. A. 1995, MNRAS, 273, 328CrossRefGoogle Scholar
Clegg, A. W. & Corders, J. M. 1991, ApJ, 374, 150CrossRefGoogle Scholar
Fish, V. L., Brisken, W. F., & Sjouwerman, L. O. 2006, ApJ, 647, 418CrossRefGoogle Scholar
Ramachandran, R., Deshpande, A. A., & Goss, W. M. 2006, ApJ, 653, 1314CrossRefGoogle Scholar
Rickard, L. J., Palmer, P., & Zuckerman, B. 1975, ApJ, 200, 6CrossRefGoogle Scholar
Salem, M. & Middleton, M. S. 1978, MNRAS, 183, 491CrossRefGoogle Scholar
Scappaticci, G. A. & Watson, W. D. 1992, ApJ, 400, 351CrossRefGoogle Scholar
Slysh, V. I., Alakoz, A. V., & Migenes, V. 2010, MNRAS, 404, 1121Google Scholar
Wright, M. M., Gray, M. D., & Diamond, P. J. 2004, MNRAS, 350, 1253CrossRefGoogle Scholar
Zuckerman, B., Yen, J. L., Gottlieb, C. A., & Palmer, P. 1972, ApJ, 177, 59CrossRefGoogle Scholar