Kennea and Amaral-Rogers (GCN Circ. 15335) reported the initial Swift results. On October 14, 2013 at 17:24 UT, Swift began a series of target of opportunity observations to cover the region around GRB131014A (Fitzpatrick et al., GCN Circ. 15332, Evans, GCN Circ. 15334), approximately 12.3 hours after the burst was detected by Fermi. Table 1 contains the best reported positions from Swift, and the latest XRT position can be viewed at http://www.swift.ac.uk/xrt_positions.
Table 2 is a summary of GCN Circulars about this GRB from observatories other than Swift.
BAT results are not available.
Analysis of the initial XRT data was reported by Amaral-Rogers et al. (GCN Circ. 15344). We have analysed 11 ks of XRT data for the Fermi/LAT-detected burst: GRB 131014A, from 44.1 ks to 173.4 ks after the Fermi/LAT trigger. The data are entirely in Photon Counting (PC) mode.
The light curve (Figure 2) can be modelled with a power-law decay with a decay index of α=1.53 ± 0.28.
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.2 (+0.7, -0.6). The best-fitting absorption column is 6.8 (+4.0, -3.0) x 1021 cm-2, in excess of the Galactic value of 2.2 x 1021 cm-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.9 x 10-11 (8.5 x 10-11) erg cm-2 count-1.
The Swift/UVOT began observations of the field of GRB 131014A starting approximately 45.7 ks after the Fermi LAT detection (Desiante et al. 2013, GCN Circ. 15333) (Swenson and Amaral-Rogers GCN Circ. 15342). We do not detect any new source consistent with the NOT afterglow candidate (Schulze et al. 2013, GCN Circ. 15337). Table 3 gives preliminary magnitudes using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc., 1358, 373). No correction has been made for the expected extinction in the Milky Way corresponding to a reddening of EB-V of 0.22 mag. in the direction of the GRB (Schlegel et al. 1998).
Figure 1. The BAT light curve is not available.
RA (J2000) | Dec (J2000) | Error | Note | Reference |
---|---|---|---|---|
06h41m12.18s | -19°05'49.4" | 3.9" | XRT-final | UKSSDC |
06h41m12.80s | -19°05'49.6" | 6" | XRT | Evans and Osborne GCN Circ. 15351 |
Band | Authors | GCN Circ. | Subject | Observatory | Notes |
---|---|---|---|---|---|
Optical | Xu et al. | 15336 | Nanshan optical observations | Xinjiang Astro.Obs. | |
Optical | Schulze et al. | 15337 | NOT afterglow candidate | NOT | detection |
Optical | Troja et al. | 15340 | RATIR Optical and NIR Observations | RATIR | detection |
Optical | Troja et al. | 15346 | RATIR Optical/NIR Afterglow Confirmation | RATIR | detection |
Optical | Kann et al. | 15347 | GROND observations | GROND | |
Optical | Troja et al. | 15364 | RATIR Optical/NIR Afterglow Retraction | RATIR | retraction |
Gamma-ray | Fitzpatrick and Xiong | 15332 | Fermi GBM detection | Fermi GBM | Epeak = 318 ± 3 keV |
Gamma-ray | Desiante et al. | 15333 | Fermi-LAT detection | Fermi LAT | detection |
Gamma-ray | Golenetskii et al. | 15338 | Konus-Wind observation | Konus-Wind | Epeak = 346 ± 9 keV |
Gamma-ray | Kawano et al. | 15348 | Suzaku WAM observation of the prompt emission | Suzaku WAM | light curve |
Gamma-ray | Hurley et al. | 15363 | IPN Triangulation | IPN |
Filter | Tstart | Tstop | Exposure | Mag |
---|---|---|---|---|
u | 45,688 | 74,324 | 1239 | >20.9 |
Table 3. UVOT observation reported by Swenson and Amaral-Rogers (GCN Circ. 15342). The start and stop time of the exposure are given in seconds since the BAT trigger. The preliminary 3-σ upper limit is given. No correction has been made for extinction in the Milky Way.