On the Existence of the Plateau Emission in High-energy Gamma-Ray Burst Light Curves Observed by Fermi-LAT
Por:
Dainotti, M. G., Omodei, N., Srinivasaragavan, G. P., Vianello, G., Willingale, R., O'Brien, P., Nagataki, S., Petrosian, V, Nuygen, Z., Hernandez, X., Axelsson, M., Bissaldi, E., Longo, F.
Publicada:
1 jul 2021
Resumen:
The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space
Telescope (Fermi) shows long-lasting high-energy emission in many
gamma-ray bursts (GRBs), similar to X-ray afterglows observed by the
Neil Gehrels Swift Observatory (Swift). Some LAT light curves (LCs) show
a late-time flattening reminiscent of X-ray plateaus. We explore the
presence of plateaus in LAT temporally extended emission analyzing GRBs
from the second Fermi-LAT GRB Catalog from 2008 to 2016 May with known
redshifts, and check whether they follow closure relations corresponding
to four distinct astrophysical environments predicted by the external
forward shock model. We find that three LCs can be fit by the same
phenomenological model used to fit X-ray plateaus and show tentative
evidence for the existence of plateaus in their high-energy extended
emission. The most favorable scenario is a slow-cooling regime, whereas
the preferred density profile for each GRBs varies from a
constant-density interstellar medium to an r (-2) wind environment. We
also compare the end time of the plateaus in gamma-rays and X-rays using
a statistical comparison with 222 Swift GRBs with plateaus and known
redshifts from 2005 January to 2019 August. Within this comparison, the
case of GRB 090510 shows an indication of chromaticity at the end time
of the plateau. Finally, we update the 3D fundamental plane relation
among the rest-frame end time of the plateau, its correspondent
luminosity, and the peak prompt luminosity for 222 GRBs observed by
Swift. We find that these three LAT GRBs follow this relation.
Filiaciones:
Dainotti, M. G.:
Natl Astron Observ Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan
Space Sci Inst, Boulder, CO 80301 USA
Omodei, N.:
Stanford Univ, Phys Dept, 382 Via Pueblo Mall, Stanford, CA 94305 USA
Srinivasaragavan, G. P.:
CALTECH, Cahill Ctr Astrophys, 1200 E Calif Blvd, Pasadena, CA 91125 USA
Univ Maryland, Dept Astron, College Pk, MD 20742 USA
Vianello, G.:
Stanford Univ, Phys Dept, 382 Via Pueblo Mall, Stanford, CA 94305 USA
Willingale, R.:
Univ Leicester, Sch Phys & Astron, Leicester, Leics, England
O'Brien, P.:
Univ Leicester, Astron Dept, Leicester, Leics, England
Nagataki, S.:
RIKEN Cluster Pioneering Res, Astrophys Big Bang Lab ABBL, Tokyo, Japan
Petrosian, V:
Stanford Univ, Phys Dept, 382 Via Pueblo Mall, Stanford, CA 94305 USA
Nuygen, Z.:
Univ Calif Los Angeles, Astron Dept, 475 Portola Plaza, Los Angeles, CA USA
Hernandez, X.:
Univ Nacl Autonoma Mexico, Inst Astron, AP 70-264, Cdmx 04510, Mexico
Axelsson, M.:
Stockholm Univ, Dept Phys, SE-10691 Stockholm, Sweden
Stockholm Univ, Dept Astron, SE-10691 Stockholm, Sweden
KTH Royal Inst Technol, Dept Phys, SE-10691 Stockholm, Sweden
Oskar Klein Ctr, SE-10691 Stockholm, Sweden
Bissaldi, E.:
Univ Bari, Dipartimento Interateneo Fis, Via E Orabona 4, I-70125 Bari, Italy
Politecn Bari, Via E Orabona 4, I-70125 Bari, Italy
Ist Nazl Fis Nucl, Sez Bari, Via E Orabona 4, I-70125 Ban, Italy
Longo, F.:
Univ Trieste, Dipartimento Fis, Via A Valerio 2, I-34127 Trieste, Italy
Ist Nazl Fis Nucl, Sez Trieste, Via A Valerio 2, I-34127 Trieste, Italy
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