Mirabal, Nestoret al.2020-09-042020-09-042008-09-20Adria C. Updike et al., The Rapidly Flaring Afterglow of the Very Bright and Energetic GRB 070125, The Astrophysical Journal, 685: 361-375 (2008), doi: https://doi.org/10.1086%2F590236https://doi.org/10.1086%2F590236http://hdl.handle.net/11603/19594Adria C. Updike, Josh B. Haislip, Melissa C. Nysewander, Andrew S. Fruchter, D. Alexander Kann, Sylvio Klose, Peter A. Milne, G. Grant Williams, Weikang Zheng, Carl W. Hergenrother, Jason X. Prochaska, Jules P. Halpern, Nestor Mirabal, John R. Thorstensen, Alexander J. van der Horst, Rhaana L. C. Starling, Judith L. Racusin, David N. Burrows, N. P. M. Kuin, Peter W. A. Roming, Eric Bellm, Kevin Hurley, Weidong Li, Alexei V. Filippenko, Cullen Blake, Dan Starr, Emilio E. Falco, Warren R. Brown, Xinyu Dai, Jinsong Deng, Liping Xin, Yulei Qiu, Jianyan Wei, Yuji Urata, Domenico Nanni, Elisabetta Maiorano, Eliana Palazzi, Giuseppe Greco, Corrado Bartolini, Adriano Guarnieri, Adalberto Piccioni, Graziella Pizzichini, Federica Terra, Kuntal Misra, B. C. Bhatt, G. C. Anupama, X. Fan, L. Jiang, Ralph A. M. J. Wijers, Daniel E. Reichart, Hala A. Eid, Ginger Bryngelson, Jason Puls, R. C. Goldthwaite, and Dieter H. Hartmann.We report on multiwavelength observations, ranging from X-ray to radio wave bands, of the IPN-localized gamma-ray burst GRB 070125. Spectroscopic observations reveal the presence of absorption lines due to O I, Si II, and C IV, implying a likely redshift of z = 1.547. The well-sampled light curves, in particular from 0.5 to 4 days after the burst, suggest a jet break at 3.7 days, corresponding to a jet opening angle of ~7.0°, and implying an intrinsic GRB energy in the 1-10,000 keV band of around Eγ = (6.3–6.9) × 10⁵¹ ergs (based on the fluences measured by the gamma-ray detectors of the IPN). GRB 070125 is among the brightest afterglows observed to date. The SED implies a host extinction of AV < 0.9 mag . Two rebrightening episodes are observed, one with excellent time coverage, showing an increase in flux of 56% in ~8000 s. The evolution of the afterglow light curve is achromatic at all times. Late-time observations of the afterglow do not show evidence for emission from an underlying host galaxy or supernova. Any host galaxy would be subluminous, consistent with current GRB host galaxy samples. Evidence for strong Mg II absorption features is not found, which is perhaps surprising in view of the relatively high redshift of this burst and the high likelihood for such features along GRB-selected lines of sight.15 pagesen-USThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.Public Domain Mark 1.0This work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Lawhttp://creativecommons.org/publicdomain/mark/1.0/Text