GRB 191029A: Swift-XRT refined Analysis
Abstract
We have analysed 9.0 ks of XRT data for GRB 191029A (Evans et al. GCN Circ. 26088), from 4.0 ks to 27.7 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 352.1492, -40.5661 which is equivalent to: RA (J2000): 23 28 35.80 Dec(J2000): -40 33 58.0 with an uncertainty of 3.6 arcsec (radius, 90% confidence). The light curve is consistent with a constant source of mean count rate 8.2e-02 ct/sec. A power-law fit gives an index of 0.08 (+0.12, -0.13). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.54 (+0.16, -0.10). The best-fitting absorption column is 1.92 (+3.90, -0.14) x 10^20 cm^-2, consistent with the Galactic value of 1.8 x 10^20 cm^-2 (Willingale et al. 2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10^-11 (4.0 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 1.92 (+3.90, -0.14) x 10^20 cm^-2 Galactic foreground: 1.8 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 1.54 (+0.16, -0.10) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00932058. This circular is an official product of the Swift-XRT team.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- October 2019
- Bibcode:
- 2019GCN.26094....1D