@article{162f0e514c5a4f4a83a032c39d613d88,
title = "GRB 191016A: The onset of the forward shock and evidence of late energy injection",
abstract = "We present optical and near-infrared (NIR) photometric observations of GRB 191016 with the COATLI,DDOTI, and RATIR ground-based telescopes over the first three nights. We present the temporal evolution of the optical afterglow and describe five different stages that were not completely characterized in previous works, mainly due to scarcity of data points to accurately fit the different components of the optical emission. After the end of the prompt gamma-ray emission, we observed the afterglow rise slowly in the optical and NIR wavelengths and peak at around T + 1450 s in all filters. This was followed by an early decay, a clear plateau from T + 5000 s to T + 11 000 s, and then a regular late decay. We also present evidence of the jet break at later times, with a temporal index in good agreement with the temporal slope obtained from X-ray observations. Although many of the features observed in the optical light curves of gamma-ray bursts are usually well explained by a reverse shock (RS) or forward shock (FS), the shallowness of the optical rise and enhanced peak emission in the GRB 191016A afterglow is not well fitted by only a FS or a RS. We propose a theoretical model which considers both of these components and combines an evolving FS with a later embedded RS and a subsequent late energy injection from the central engine activity. We use this model to successfully explain the temporal evolution of the light curves and discuss its implications on the fireball properties.",
keywords = "gamma-ray burst: individual: GRB 191016A, methods: observational, techniques: photometric",
author = "M. Pereyra and N. Fraija and Watson, {A. M.} and Becerra, {R. L.} and Butler, {N. R.} and {De Colle}, F. and E. Troja and S. Dichiara and E. Fraire-Bonilla and Lee, {W. H.} and E. Ramirez-Ruiz and Bloom, {J. S.} and Prochaska, {J. X.} and Kutyrev, {A. S.} and Gonz{\'a}lez, {J. J.} and Richer, {M. G.}",
note = "Funding Information: This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. Some of the data used in this paper were acquired with the RATIR instrument, funded by the University of California and NASA Goddard Space Flight Center, and the 1.5 m Harold L. Johnson telescope at the Observatorio Astron{\'o}mico Nacional on the Sierra de San Pedro M{\'a}rtir, operated and maintained by the Observatorio Astron{\'o}mico Nacional and the Instituto de Astronom{\'i}a of the Universidad Nacional Aut{\'o}noma de M{\'e}xico. Operations are partially funded by the Universidad Nacional Aut{\'o}noma de M{\'e}xico, v{\'i}a the Direcci{\'o}n General Asuntos del Personal Acad{\'e}mico (DGAPA) and Programa de Apoyo a Proyectos de Investigaci{\'o}n e Innovaci{\'o}n Tecnol{\'o}gica (PAPIIT) under project numbers IG100414, IT102715, AG100317, IN109418, IG100820, and IN105921. We acknowledge the contribution of Leonid Georgiev and Neil Gehrels to the development of RATIR . Some of the data used in this paper were acquired with the DDOTI instrument and the COATLI telescope and interim instrument at the Observatorio Astron{\'o}mico Nacional on the Sierra de San Pedro M{\'a}rtir. DDOTI and COATLI are partially funded by the Consejo Nacional de Ciencia y Tecnolog{\'i}a (CONACYT) under project numbers LN 232649, LN 260369, LN 271117, and 277901, the Universidad Nacional Aut{\'o}noma de M{\'e}xico by the Coordinaci{\'o}n de la Investigaci{\'o}n Cient{\'i}fica (CIC) and DGAP A/P APIIT under project numbers IG100414, IT102715, AG100317, IN109418, and IN105921, and the NASA Goddard Space Flight Center. DDOTI is partially funded by the University of Maryland (NNX17AK54G). DDOTI and COATLI are operated and maintained by the Observatorio Astron{\'o}mico Nacional and the Instituto de Astronom{\'i}a of the Universidad Nacional Aut{\'o}noma de M{\'e}xico. We acknowledge the contribution of Neil Gehrels to the development of DDOTI . Rosa Leticia Becerra acknowledges support from the DGAPA-UNAM and CONACYT postdoctoral fellowships. We thank the staff of the Observatorio Astron{\'o}mico Nacional. Publisher Copyright: {\textcopyright} 2022 The Author(s).",
year = "2022",
month = apr,
day = "1",
doi = "10.1093/mnras/stac389",
language = "English (US)",
volume = "511",
pages = "6205--6217",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "4",
}