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 discov- 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 2 × 10 3 , 2 × 10 4 , and 2 × 10 5 seconds.

GRB 191016A: A Long Gamma-Ray Burst Detected by TESS

“…Wang et al (2013) ferentiated the observed afterglow population by postburst time and light curve morphology, finding apparent magnitude distributions peaking at R = 16.1, 17.3, and 18.4 mag for 100 s, 1000 s, and 3600 s (1 hr) after the burst. Roming et al (2017) report the UVOT magnitudes of the first-observed data point and the afterglow peak as 17.06 and 17.7 mag, respectively. We reproduce these populations in Figure 7, and overplot the TESS 10% photometry limit.…”

“…The most recent full catalog of UVOT GRB afterglows (Roming et al 2017) contains 626 total bursts detected by multiple gamma ray missions over six years, of which 538 (86%) were followed up with UVOT. The majority of the remainder were too close to the sun or moon for follow-up, as is the case with GRB 191016A, while a few occurred during instrument downtime.…”

Exploring the canonical behaviour of long gamma-ray bursts with an intrinsic multiwavelength afterglow correlation

“…The optical/UV sample consists of 56 long duration GRBs, selected from the second Swift UVOT GRB afterglow catalogue [19], which were observed between April 2005 and December 2010. They were selected using the criteria of [20].…”

A study of gamma-ray burst afterglows as they first come into view of the SwiftUltraviolet and Optical Telescope

“…With these criteria in mind, we have started with the sample of GRBs studied by Oates et al (2012). The sample of Oates et al (2012) was drawn from the second UVOT GRB catalogue (Roming et al, 2017), which contains all of the GRBs observed with Swift UVOT from the launch of Swift until 25 December 2010. For inclusion in their sample, Oates et al (2012) required that a GRB must have been observed by UVOT within the first 400s after the BAT trigger and have a measurement of redshift, reflecting our criteria (b) and (c).…”

“…Oates et al, 2012). The main reason is that photometry derived from the settling exposure is regarded as uncertain because of the changing UVOT photocathode voltage at the beginning of the exposure; the rapidly changing spacecraft attitude can also be a cause for concern (Roming et al, 2017). The settling exposure usually begins 10-15 seconds before the first settled exposure, and so represents a significant shifting forward of the afterglow observations, if the photometry can be trusted.…”