CaltechAUTHORS
Published October 20, 2013 | Version Published + Submitted
Journal Article Open

Discovery and redshift of an optical afterglow in 71 deg^2: iPTF13bxl and GRB 130702A

Creators

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Carnegie Observatories
  • 3. ROR icon Weizmann Institute of Science
  • 4. ROR icon Syracuse University
  • 5. ROR icon University of California, Berkeley
  • 6. ROR icon Lawrence Berkeley National Laboratory
  • 7. ROR icon George Washington University
  • 8. ROR icon National Radio Astronomy Observatory
  • 9. ROR icon Infrared Processing and Analysis Center
  • 10. ROR icon Max Planck Institute for Extraterrestrial Physics

Abstract

We report the discovery of the optical afterglow of the γ-ray burst (GRB) 130702A, identified upon searching 71 deg^2 surrounding the Fermi Gamma-ray Burst Monitor (GBM) localization. Discovered and characterized by the intermediate Palomar Transient Factory, iPTF13bxl is the first afterglow discovered solely based on a GBM localization. Real-time image subtraction, machine learning, human vetting, and rapid response multi-wavelength follow-up enabled us to quickly narrow a list of 27,004 optical transient candidates to a single afterglow-like source. Detection of a new, fading X-ray source by Swift and a radio counterpart by CARMA and the Very Large Array confirmed the association between iPTF13bxl and GRB 130702A. Spectroscopy with the Magellan and Palomar 200 inch telescopes showed the afterglow to be at a redshift of z = 0.145, placing GRB 130702A among the lowest redshift GRBs detected to date. The prompt γ-ray energy release and afterglow luminosity are intermediate between typical cosmological GRBs and nearby sub-luminous events such as GRB 980425 and GRB 060218. The bright afterglow and emerging supernova offer an opportunity for extensive panchromatic follow-up. Our discovery of iPTF13bxl demonstrates the first observational proof-of-principle for ~10 Fermi-iPTF localizations annually. Furthermore, it represents an important step toward overcoming the challenges inherent in uncovering faint optical counterparts to comparably localized gravitational wave events in the Advanced LIGO and Virgo era.

Additional Information

© 2013 American Astronomical Society. Received 2013 July 20; accepted 2013 September 9; published 2013 October 7. We acknowledge A. Weinstein, A. Gal-Yam, R. Quimby, V. Connaughton, and the Fermi-GBM team for valuable discussions, S. Caudill, S. Tinyanont, D. Khatami for P200 observing, and the developers of the COSMOS package for Magellan data reduction. This research is supported by the National Science Foundation through a Graduate Research Fellowship for L.P.S., award PHY-0847611 for D.A.B., and NSF-CDI grant for J.S.B. M.M.K. acknowledges generous support from the Carnegie-Princeton Fellowship. M.M.K. and D.A.P. are supported by NASA through the Hubble Fellowship grants HST-HF-51293.01 and HST-HF-51296.01-A, awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555. E.O.O. is the incumbent of the Arye Dissentshik career development chair and is supported by grants from the Israeli Ministry of Science and the I-CORE Program. D.A.B. is further supported by an RCSA Cottrell Scholar award. This research made use of Astropy (Robitaille et al. 2013, http://www.astropy.org), a community-developed core Python package for Astronomy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

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Published - 2041-8205_776_2_L34.pdf

Submitted - 1307.5851v4.pdf

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Additional details

Additional titles

Alternative title
Discovery and redshift of an optical afterglow in 71 square degrees: iPTF13bxl and GRB 130702A

Identifiers

Eprint ID
42224
Resolver ID
CaltechAUTHORS:20131104-131232227

Related works

Describes
http://arxiv.org/abs/1307.5851 (URL)

Funding

NSF Graduate Research Fellowship
PHY-0847611
NSF
CDI-0941742
Carnegie-Princeton Fellowship
NASA Hubble Fellowship
HST-HF-51293.01
NASA Hubble Fellowship
HST-HF-51296.01-A
NASA
NAS 5-26555
Ministry of Science (Israel)
I-CORE Program
Cottrell Scholar of Research Corporation

Dates

Created
2013-11-04
Created from EPrint's datestamp field
Updated
2021-11-10
Created from EPrint's last_modified field

Caltech Custom Metadata

Caltech groups
Palomar Transient Factory, Infrared Processing and Analysis Center (IPAC), Division of Geological and Planetary Sciences (GPS)