Evidence for gravitational lensing of GRB 200716C. (arXiv:2107.11050v2 [astro-ph.HE] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Yang_X/0/1/0/all/0/1">Xing Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_H/0/1/0/all/0/1">Hou-Jun L&#xfc;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yuan_H/0/1/0/all/0/1">Hao-Yu Yuan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rice_J/0/1/0/all/0/1">Jared Rice</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_Z/0/1/0/all/0/1">Zhao Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_B/0/1/0/all/0/1">Bin-Bin Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liang_E/0/1/0/all/0/1">En-Wei Liang</a>

Observationally, there are a small fraction of GRBs with prompt emission
observed by Fermi/GBM that are composed of two pulses. Occasionally, the
distance to a GRB may be lensed when a high mass astrophysical object resides
in the path between the GRB source and observer. In this paper, describe GRB
200716C which has a two-pulse emission and duration of a few seconds. We
present a Bayesian analysis identifying gravitational lensing in both temporal
and spectral properties, and calculate the time delay ($Delta tsim 1.92$ s)
and magnification ($gammasim 1.5$) between those two pulses based on the
temporal fits. One can roughly estimate the lens mass to be about $2.4times
10^{5}~M_{odot}$ in the rest frame. We also calculate the false alarm
probability for this detection to be about 0.07% with trial factors, and a
present-day number density of about $808 rm~Mpc^{-3}$ with an energy density
$Omegasim 1.4times 10^{-3}$. If the first pulse of this GRB near the trigger
time is indeed gravitationally echoed by a second pulse, GRB 200716C may be a
short GRB candidate with extended emission.

Observationally, there are a small fraction of GRBs with prompt emission
observed by Fermi/GBM that are composed of two pulses. Occasionally, the
distance to a GRB may be lensed when a high mass astrophysical object resides
in the path between the GRB source and observer. In this paper, describe GRB
200716C which has a two-pulse emission and duration of a few seconds. We
present a Bayesian analysis identifying gravitational lensing in both temporal
and spectral properties, and calculate the time delay ($Delta tsim 1.92$ s)
and magnification ($gammasim 1.5$) between those two pulses based on the
temporal fits. One can roughly estimate the lens mass to be about $2.4times
10^{5}~M_{odot}$ in the rest frame. We also calculate the false alarm
probability for this detection to be about 0.07% with trial factors, and a
present-day number density of about $808 rm~Mpc^{-3}$ with an energy density
$Omegasim 1.4times 10^{-3}$. If the first pulse of this GRB near the trigger
time is indeed gravitationally echoed by a second pulse, GRB 200716C may be a
short GRB candidate with extended emission.

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