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Title: Chandra Observations of the X-Ray Environs of SN 1998BW / GRB 980425

Abstract

We report X-ray studies of the environs of SN 1998bw and GRB 980425 using the Chandra X-Ray Observatory 1281 days after the GRB. Eight X-ray point sources were localized, three and .ve each in the original error boxes--S1 and S2--assigned for variable X-ray counterparts to the GRB by BeppoSAX. The sum of the discrete X-ray sources plus continuous emission in S2 observed by CXO on day 1281 is within a factor of 1.5 of the maximum and the upper limits seen by BeppoSAX. We conclude that S2 is the sum of several variable sources that have not disappeared, and therefore is not associated with the GRB. Within S1, clear evidence is seen for a decline of approximately a factor of 12 between day 200 and day 1281. One of the sources in S1, S1a, is coincident with the well-determined radio location of SN 1998bw, and is certainly the remnant of that explosion. The nature of the other sources is also discussed. Combining our observation of the supernova with others of the GRB afterglow, a smooth X-ray light curve, spanning {approx} 1300 days, is obtained by assuming the burst and supernova were coincident at 35.6 Mpc. When this X-ray light curvemore » is compared with those of the X-ray ''afterglows'' of ordinary GRBs, X-ray Flashes, and ordinary supernovae, evidence emerges for at least two classes of lightcurves, perhaps bounding a continuum. By three to ten years, all these phenomena seem to converge on a common X-ray luminosity, possibly indicative of the supernova underlying them all. This convergence strengthens the conclusion that SN 1998bw and GRB 980425 took place in the same object. One possible explanation for the two classes is a (nearly) standard GRB observed at different angles, in which case X-ray afterglows with intermediate luminosities should eventually be discovered. Finally, we comment on the contribution of GRBs to the ULX source population.« less

Authors:
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE Office of Science (US)
OSTI Identifier:
827302
Report Number(s):
SLAC-PUB-10545
TRN: US200425%%560
DOE Contract Number:  
AC03-76SF00515
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 14 Jul 2004
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AFTERGLOW; CONVERGENCE; LUMINOSITY; POINT SOURCES; SUPERNOVAE; X-RAY SOURCES

Citation Formats

Kouveliotou, C. Chandra Observations of the X-Ray Environs of SN 1998BW / GRB 980425. United States: N. p., 2004. Web. doi:10.2172/827302.
Kouveliotou, C. Chandra Observations of the X-Ray Environs of SN 1998BW / GRB 980425. United States. https://doi.org/10.2172/827302
Kouveliotou, C. 2004. "Chandra Observations of the X-Ray Environs of SN 1998BW / GRB 980425". United States. https://doi.org/10.2172/827302. https://www.osti.gov/servlets/purl/827302.
@article{osti_827302,
title = {Chandra Observations of the X-Ray Environs of SN 1998BW / GRB 980425},
author = {Kouveliotou, C},
abstractNote = {We report X-ray studies of the environs of SN 1998bw and GRB 980425 using the Chandra X-Ray Observatory 1281 days after the GRB. Eight X-ray point sources were localized, three and .ve each in the original error boxes--S1 and S2--assigned for variable X-ray counterparts to the GRB by BeppoSAX. The sum of the discrete X-ray sources plus continuous emission in S2 observed by CXO on day 1281 is within a factor of 1.5 of the maximum and the upper limits seen by BeppoSAX. We conclude that S2 is the sum of several variable sources that have not disappeared, and therefore is not associated with the GRB. Within S1, clear evidence is seen for a decline of approximately a factor of 12 between day 200 and day 1281. One of the sources in S1, S1a, is coincident with the well-determined radio location of SN 1998bw, and is certainly the remnant of that explosion. The nature of the other sources is also discussed. Combining our observation of the supernova with others of the GRB afterglow, a smooth X-ray light curve, spanning {approx} 1300 days, is obtained by assuming the burst and supernova were coincident at 35.6 Mpc. When this X-ray light curve is compared with those of the X-ray ''afterglows'' of ordinary GRBs, X-ray Flashes, and ordinary supernovae, evidence emerges for at least two classes of lightcurves, perhaps bounding a continuum. By three to ten years, all these phenomena seem to converge on a common X-ray luminosity, possibly indicative of the supernova underlying them all. This convergence strengthens the conclusion that SN 1998bw and GRB 980425 took place in the same object. One possible explanation for the two classes is a (nearly) standard GRB observed at different angles, in which case X-ray afterglows with intermediate luminosities should eventually be discovered. Finally, we comment on the contribution of GRBs to the ULX source population.},
doi = {10.2172/827302},
url = {https://www.osti.gov/biblio/827302}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jul 14 00:00:00 EDT 2004},
month = {Wed Jul 14 00:00:00 EDT 2004}
}