Reverse Shock Emission Revealed in Early Photometry in the Candidate Short GRB 180418A
Por:
Becerra, R. L., Dichiara, S., Watson, A. M., Troja, E., Fraija, N., Klotz, A., Butler, N. R., Lee, W. H., Veres, P., Turpin, D., Bloom, J. S., Boer, M., Gonzalez, J. J., Kutyrev, A. S., Prochaska, J. X., Ramirez-Ruiz, E., Richer, M. G.
Publicada:
10 ago 2019
Resumen:
We present observations of the possible short GRB 180418A in gamma-rays,
X-rays, and in the optical. Early optical photometry with the TAROT and
RATIR instruments shows a bright peak (approximate to 14.2 AB mag)
between T + 28 and T + 90 s that we interpret as the signature of a
reverse shock. Later observations can be modeled by a standard forward
shock model and show no evidence of a jet break, allowing us to
constrain the jet collimation to theta(j) > 7 degrees. Using deep
late-time optical observations, we place an upper limit of r > 24 AB mag
on any underlying host galaxy. The detection of the afterglow in the
Swift UV filters constrains the GRB redshift to z < 1.3 and places an
upper bound on the gamma-ray isotropic equivalent energy E-gamma,E- iso
< 3 x 10(51) erg. The properties of this GRB (e.g., duration, hardness
ratio, energy, and environment) lie at the intersection between short
and long bursts, and we cannot conclusively identify its type. We
estimate that the probability that it is drawn from the population of
short GRBs is 10%-30%.
Filiaciones:
Becerra, R. L.:
Univ Nacl Autonoma Mexico, Inst Astron, Apartado Postal 70-264, Mexico City 04510, Cdmx, Mexico
Dichiara, S.:
Univ Maryland, Dept Astron, College Pk, MD 20742 USA
NASA, Astrophys Sci Div, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA
Watson, A. M.:
Univ Nacl Autonoma Mexico, Inst Astron, Apartado Postal 70-264, Mexico City 04510, Cdmx, Mexico
Troja, E.:
Univ Maryland, Dept Astron, College Pk, MD 20742 USA
NASA, Astrophys Sci Div, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA
Fraija, N.:
Univ Nacl Autonoma Mexico, Inst Astron, Apartado Postal 70-264, Mexico City 04510, Cdmx, Mexico
Klotz, A.:
Inst Rech Astronophys & Planetol, 14 Ave Edouard Belin, F-31400 Toulouse, France
Butler, N. R.:
Arizona State Univ, Sch Earth & Space Explorat, Tempe, AZ 85287 USA
Lee, W. H.:
Univ Nacl Autonoma Mexico, Inst Astron, Apartado Postal 70-264, Mexico City 04510, Cdmx, Mexico
Veres, P.:
Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA
Turpin, D.:
Chinese Acad Sci, Natl Astron Observ, 20A Datun Rd, Beijing 100012, Peoples R China
Bloom, J. S.:
Univ Maryland, Dept Astron, College Pk, MD 20742 USA
Boer, M.:
CNRS, UMR 7250, ARTEMIS, OCA,UNS, Blvd Observ,BP 4229, F-06304 Nice, France
Gonzalez, J. J.:
Univ Nacl Autonoma Mexico, Inst Astron, Apartado Postal 70-264, Mexico City 04510, Cdmx, Mexico
Kutyrev, A. S.:
NASA, Astrophys Sci Div, Goddard Space Flight Ctr, 8800 Greenbelt Rd, Greenbelt, MD 20771 USA
Prochaska, J. X.:
Univ Calif Santa Cruz, UCO Lick Observ, Dept Astron & Astrophys, 1156 High St, Santa Cruz, CA 95064 USA
Ramirez-Ruiz, E.:
Univ Calif Santa Cruz, UCO Lick Observ, Dept Astron & Astrophys, 1156 High St, Santa Cruz, CA 95064 USA
Richer, M. G.:
Univ Nacl Autonoma Mexico, Unidad Acad Ensenada, Inst Astron, Ensenada 22860, Baja California, Mexico
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