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A Large Catalog of Homogeneous Ultra-Violet/Optical GRB Afterglows: Temporal and Spectral Evolution

Abstract:

We present the second Swift Ultra-Violet/Optical Telescope (UVOT) gamma-ray burst (GRB) afterglow catalog, greatly expanding on the first Swift UVOT GRB afterglow catalog. The second catalog is constructed from a database containing over 120,000 independent UVOT observations of 538 GRBs first detected by Swift, the High Energy Transient Explorer 2 (HETE2), the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), the Interplanetary Network (IPN), Fermi, and Astro-rivelatore Gamma a Immagini Leggero (AGILE). The catalog covers GRBs discovered from 2005 Jan 17 to 2010 Dec 25. Using photometric information in three UV bands, three optical bands, and a `white' or open filter, the data are optimally co-added to maximize the number of detections and normalized to one band to provide a detailed light curve. The catalog provides positional, temporal, and photometric information for each burst, as well as Swift Burst Alert Telescope (BAT) and X-Ray Telescope (XRT) GRB parameters. Temporal slopes are provided for each UVOT filter. The temporal slope per filter of almost half the GRBs are fit with a single power-law, but one to three breaks are required in the remaining bursts. Morphological comparisons with the X-ray reveal that 75% of the UVOT light curves are similar to one of the four morphologies identified by Evans et al. (2009). The remaining 25% have a newly identified morphology. For many bursts, redshift and extinction corrected UV/optical spectral slopes are also provided at 2x10³, 2x10⁴, and 2x10⁵ seconds.

Authors:

Peter W. A. Roming^{1, 2, 3}, T. Scott Koch⁴, Samantha R. Oates⁵, Blair L. Porterfield⁶, Amanda J. Bayless^{1, 3}, Alice A. Breeveld⁵, Caryl Gronwall^{2, 7}, N. P. M. Kuin⁵, Mat J. Page⁵, Massimiliano de Pasquale⁵, Michael H. Siegel², Craig A. Swenson⁸, and Jennifer M. Tobler⁹

Affiliations:

1. Southwest Research Institute, Space Science & Engineering Division, 6220 Culebra Road, San Antonio, TX 78238-5166, USA
2. The Pennsylvania State University, Department of Astronomy & Astrophysics, 525 Davey Lab, University Park, PA 16802, USA
3. University of Texas at San Antonio, Department of Physics & Astronomy, 1 UTSA Circle, San Antonio, TX 78249, USA
4. The Pennsylvania State University, Classroom & Lab Computing, 101E Computer Building, University Park, PA 16802, USA
5. Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT, UK
6. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
7. The Pennsylvania State University, Institute for Gravitation and the Cosmos, University Park, PA 16802, USA
8. Science Systems and Applications, Inc., 10210 Greenbelt Road, Lanham, MD 20706, USA
9. University of North Dakota, Department of Space Studies, 4149 University Avenue, Grand Forks, ND 58202-9008, USA

Grab a pre-print version of the paper from astro-ph.

In Table 1 we offer a number of data products to the astronomical community. First, is a UVOT GRB Afterglow Catalog which contains a number of parameters derived for each burst, including temporal and spectral slopes. It also contains a number of other burst properties obtained from the literature. Secondly, we provide a normalized optimally co-added (NOC) database which was produced using the method described in Morgan et al. (2008). Lastly, we provide a database of raw photometric measurments derived from the UVOT Image Archive. We provide photometry derived from both 3 arcsecond and 5 arcsecond source apertures.