Cheung et al. (GCN Circ. 14971) reported the GRB detection. At 00:05:23.079 UTC on July 02, 2013, Fermi GBM triggered on GRB 130702A / Fermi394416326 (trigger 394416326). Table 1 contains the best reported positions from Swift.
Singer et al. (GCN Circ. 14967) reported the position from iPTF for the optical afterglow of this GRB. Leloudas et al. (GCN Circ. 14983) determined a redshift of 0.145 from NOT, and Mulchaey et al. (GCN Circ. 14985) determined a redshift of 0.145 from iPTF. Table 2 is a summary of GCN Circulars about this GRB from observatories other than Swift.
BAT results are not available.
We have analysed 293 ks of XRT data for the Fermi/GBM-detected burst: GRB 130702A, from 89.1 ks to 6265.5 ks after the Fermi/GBM trigger. The data are entirely in Photon Counting (PC) mode. An X-ray source is detected within the Fermi/GBM error circle.
The light curve (Figure 2) can be modelled with an initial power-law decay with an index of α=0.1 (+0.7, -1.3), followed by a break at T+125 ks to an α of 1.255 (+0.028, -0.027).
A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 1.99 (+0.14, -0.13). The best-fitting absorption column is 7.5 (+3.1, -2.8) x 1020 cm-2, in excess of the Galactic value of 1.7 x 1020 cm-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.6 x 10-11 (4.4 x 10-11) erg cm-2 count-1.
A summary of the PC-mode spectrum is thus:
Total column: 7.5 (+3.1, -2.8) x 1020 cm-2
Galactic foreground: 1.7 x 1020 cm-2
Excess significance: 3.4 σ
Photon index: 1.99 (+0.14, -0.13)
The results of the XRT team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00032876.
The Swift/UVOT began settled observations of the field of GRB 130702A 89111 s after the GBM detection (D'Avanzo et al. GCN Circ. 14973). A source consistent with the P48 position (Singer et al. 2013, GCN Circ. 14967) is detected in the initial UVOT exposures. 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 Milky Way extinction.
Figure 1. The BAT light curve is not available.
Figure 2. The XRT light curve.
Any data from a cross-hatched region are not included in the fit.
| RA (J2000) | Dec (J2000) | Error | Note | Reference |
|---|---|---|---|---|
| 14h29m14.77s | +15°46'26.5" | 0.50" | UVOT-refined | D'Avanzo et al. GCN Circ. 14973 |
| 14h29m14.78s | +15°46'26.1" | 1.5" | XRT-final | UKSSDC |
| 14h29m14.80s | +15°46'26.0" | 1.5" | XRT | D'Avanzo et al. GCN Circ. 14973 |
| Band | Authors | GCN Circ. | Subject | Observatory | Notes |
|---|---|---|---|---|---|
| Optical | Singer et al. | 14967 | Fermi394416326: iPTF detection of a ... | iPTF | possible detection |
| Optical | Guidorzi et al. | 14968 | Fermi394416326: FTN detection | FTN | detection |
| Optical | Levato et al. | 14970 | Fermi GBM trigger 394416326: MASTER ... | MASTER | upper limits |
| Optical | Xu et al. | 14975 | Fermi394416326 : Nanshan optical observations | Xinjiang Astro.Obs. | |
| Optical | D'Avanzo et al. | 14977 | TNG optical observations | TNG | detection |
| Optical | Schulze et al. | 14978 | NOT optical observations | NOT | light curve |
| Optical | Butler et al. | 14980 | RATIR Optical and NIR Observations | RATIR | detection |
| Optical | Perley et al. | 14981 | Continued P60 observations | Palomar 60-inch | |
| Optical | Leloudas et al. | 14983 | NOT spectroscopy and redshift of the ... | NOT | spectroscopy |
| Optical | D'Avanzo et al. | 14984 | further TNG observations | TNG | detection |
| Optical | Mulchaey et al. | 14985 | Redshift of Afterglow Candidate iPTF13bxl | iPTF | redshift |
| Optical | Xin et al. | 14992 | Xinglong TNT optical observation | TNT | |
| Optical | Butler et al. | 14993 | Continued RATIR Optical and NIR Observations | RATIR | detection |
| Optical | Schulze et al. | 14994 | NOT observation - the detection of an ... | NOT | |
| Optical | Pozanenko et al. | 14996 | Maidanak optical observations | Maidanak | light curve |
| Optical | Cenko et al. | 14998 | P200 Spectroscopic Confirmation of ... | Palomar 200-inch | |
| Optical | D'Elia et al. | 15000 | TNG spectroscopic observations of the ... | TNG | detection |
| Optical | Pozanenko et al. | 15003 | Maidanak optical observations | Maidanak | light curve |
| Optical | Xin et al. | 15009 | Xinglong TNT continue optical observation | TNT | |
| Optical | Khorunzhev et al. | 15243 | RTT150 optical observations | RTT150 | |
| Radio | Perley and Kasliwal | 14979 | CARMA 3mm detection | CARMA | detection |
| Radio | van der Horst | 14987 | WSRT radio detection | WSRT | detection |
| Radio | Corsi et al. | 14990 | VLA detection | VLA | detection |
| Radio | Chandra | 15002 | GMRT radio detection | GMRT | detection |
| Gamma-ray | Cheung et al. | 14971 | Fermi394416326 : Fermi-LAT detection of a ... | Fermi LAT | detection |
| Gamma-ray | Collazzi and Connaughton | 14972 | Fermi394416326: Fermi GBM detection | Fermi GBM | detection |
| Gamma-ray | Hurley et al. | 14974 | IPN localization of GRB 130702A (= Fermi ... | IPN | |
| Gamma-ray | Golenetskii et al. | 14986 | Konus-Wind observation | Konus-Wind | light curve |
| Other | Amati et al. | 15025 | in the Ep,i - Eiso plane |
| Filter | Tstart(s) | Tstop(s) | Exp(s) | Mag |
|---|---|---|---|---|
| white | 89232 | 95967 | 3414 | 18.26 ± 0.04 |
Table 3. UVOT observation reported by D'Avanzo et al. (GCN Circ. 14973). The start and stop time of the exposure are given in seconds since the BAT trigger. The preliminary detection is given. No correction has been made for extinction in the Milky Way.