Radio observations of GRB 100418a: Test of an energy injection model explaining long-lasting GRB afterglows
Abstract
We present the results of our radio observational campaign of gamma-ray burst (GRB) 100418a, for which we used the Australia Telescope Compact Array, the Very Large Array, and the Very Long Baseline Array. GRB 100418a was a peculiar GRB with unusual X-ray and optical afterglow profiles featuring a plateau phase with a very shallow rise. This observed plateau phase was believed to be due to a continued energy injection mechanism that powered the forward shock, giving rise to an unusual and long-lasting afterglow. The radio afterglow of GRB 100418a was detectable several weeks after the prompt emission. We conducted long-term monitoring observations of the afterglow and attempted to test the energy injection model advocating that the continuous energy injection is due to shells of material moving at a wide range of Lorentz factors. We obtained an upper limit of γ < 7 for the expansion rate of the GRB 100418a radio afterglow, indicating that the range-of-Lorentz factor model could only be applicable for relatively slow-moving ejecta. A preferred explanation could be that continued activity of the central engine may have powered the long-lasting afterglow.
- Authors:
-
- Shanghai Astronomical Observatory, 80 Nandan Road, Xujiahui, Shanghai 200030 (China)
- National Center for Radio Astrophysics, Tata Institute of Fundamental Research, Pune (India)
- International Centre for Radio Astronomy Research, Curtin University, Bentley 6102, WA (Australia)
- Department of Physics and Astronomy, University of New Mexico, Albuquerque, NM 87131 (United States)
- National Radio Astronomy Observatory, P.O. Box 0, Socorro, NM 87801 (United States)
- CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW (Australia)
- Publication Date:
- OSTI Identifier:
- 22348467
- Resource Type:
- Journal Article
- Journal Name:
- Astrophysical Journal
- Additional Journal Information:
- Journal Volume: 779; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; AFTERGLOW; COSMIC GAMMA BURSTS; EMISSION; EXPANSION; INJECTION; RELATIVISTIC RANGE; TELESCOPES; X RADIATION
Citation Formats
Moin, A., Wang, Z., Chandra, P., Miller-Jones, J. C. A., Tingay, S. J., Reynolds, C., Taylor, G. B., Frail, D. A., and Phillips, C. J. Radio observations of GRB 100418a: Test of an energy injection model explaining long-lasting GRB afterglows. United States: N. p., 2013.
Web. doi:10.1088/0004-637X/779/2/105.
Moin, A., Wang, Z., Chandra, P., Miller-Jones, J. C. A., Tingay, S. J., Reynolds, C., Taylor, G. B., Frail, D. A., & Phillips, C. J. Radio observations of GRB 100418a: Test of an energy injection model explaining long-lasting GRB afterglows. United States. https://doi.org/10.1088/0004-637X/779/2/105
Moin, A., Wang, Z., Chandra, P., Miller-Jones, J. C. A., Tingay, S. J., Reynolds, C., Taylor, G. B., Frail, D. A., and Phillips, C. J. 2013.
"Radio observations of GRB 100418a: Test of an energy injection model explaining long-lasting GRB afterglows". United States. https://doi.org/10.1088/0004-637X/779/2/105.
@article{osti_22348467,
title = {Radio observations of GRB 100418a: Test of an energy injection model explaining long-lasting GRB afterglows},
author = {Moin, A. and Wang, Z. and Chandra, P. and Miller-Jones, J. C. A. and Tingay, S. J. and Reynolds, C. and Taylor, G. B. and Frail, D. A. and Phillips, C. J.},
abstractNote = {We present the results of our radio observational campaign of gamma-ray burst (GRB) 100418a, for which we used the Australia Telescope Compact Array, the Very Large Array, and the Very Long Baseline Array. GRB 100418a was a peculiar GRB with unusual X-ray and optical afterglow profiles featuring a plateau phase with a very shallow rise. This observed plateau phase was believed to be due to a continued energy injection mechanism that powered the forward shock, giving rise to an unusual and long-lasting afterglow. The radio afterglow of GRB 100418a was detectable several weeks after the prompt emission. We conducted long-term monitoring observations of the afterglow and attempted to test the energy injection model advocating that the continuous energy injection is due to shells of material moving at a wide range of Lorentz factors. We obtained an upper limit of γ < 7 for the expansion rate of the GRB 100418a radio afterglow, indicating that the range-of-Lorentz factor model could only be applicable for relatively slow-moving ejecta. A preferred explanation could be that continued activity of the central engine may have powered the long-lasting afterglow.},
doi = {10.1088/0004-637X/779/2/105},
url = {https://www.osti.gov/biblio/22348467},
journal = {Astrophysical Journal},
issn = {0004-637X},
number = 2,
volume = 779,
place = {United States},
year = {Fri Dec 20 00:00:00 EST 2013},
month = {Fri Dec 20 00:00:00 EST 2013}
}