//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16003 SUBJECT: GRB 140320B: FTN optical afterglow candidate DATE: 14/03/20 10:18:18 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), A. Melandri (INAF-OAB), D. Kopac, A. Gomboc (U. Ljubljana), C.G. Mundell, F. Virgili (LJMU) on behalf of a larger collaboration report: The 2-m Faulkes Telescope North automatically began observing INTEGRAL GRB 140320B on March 20 at 09:31:27 UT (~4.6 min after the burst trigger). We find a fading uncatalogued object at coordinates RA(2000.0)= 09:42:14.17 Dec(2000.0)= +60:16:05.7 (error 1.0") with i=19.7 +- 0.1 mag at 16 minutes after the GRB, calibrated against nearby SDSS-I stars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16004 SUBJECT: GRB 140320B: A long GRB detected by INTEGRAL DATE: 14/03/20 10:20:11 GMT FROM: Sandro Mereghetti at IASF/CNR S.Mereghetti (IASF-Milano), D.Gotz (CEA, Saclay), C.Ferrigno, E.Bozzo, E.Filippova (ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report: a gamma ray burst lasting about 100 s has been detected by IBAS in the IBIS/ISGRI data at 09:26:00 UT of March 20. The refined coordinates (J2000) are: R.A.= 145.5409 deg DEC.= +60.2794 deg with an uncertainty of 2 arcmin (90% c.l.). A preliminary analysis gives a peak flux of 0.2 counts/cm2/s (20-200 keV, 1-s integration time) and a fluence in the same energy range of about 5e-7 erg/cmq. A plot of the light curve will be posted at http://ibas.iasf-milano.inaf.it/IBAS_Results.html //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16005 SUBJECT: GRB 140320B: ISON-NM optical observations DATE: 14/03/20 11:15:24 GMT FROM: Alexei Pozanenko at IKI, Moscow L. Elenin (KIAM), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed of the field of the INTEGRAL GRB 140320B (Mereghetti et al., GCN 16004) with 0.4-m telescope of ISON-NM observatory starting on Mar., 20 (UT) 09:35:41. We took unfiltered images of 30 s exposures. We detect a fading optical afterglow of GRB 140320B (Guidorzi et al., GCN 16003) in a stacked image of total exposure 300 s and do not detect it in the next stacked image of the same exposure. Coordinates of the optical afterglow (J2000) 09 42 13.96 +60 16 05.9 (uncertainties of 1 arcsec) coincide with OT coordinates (Guidorzi et al., GCN 16003). Preliminary photometry of first stacked images is based on nearby USNO-B1.0 stars: UT mid, T0+ Filter Exposure, OT, err OT mid s 09:38:39 0.00878 none 10х30 19.1 0.2 09:44:40 0.03102 none 10х30 > 19.3 UpperlLimit //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16006 SUBJECT: GRB 140320B: Xinglong TNT upper limit DATE: 14/03/20 14:05:01 GMT FROM: L.P. Xin at NAOC L. P. Xin, J. Y. Wei, T. M. Zhang, Y. L. Qiu, J. S. Deng, J. Wang, X. H. Han and C. Wu on behalf of EAFON report: We began to observe GRB 140320B (Mereghetti et al., GCN 16004) with Xinglong 0.8-m TNT telescope at 12:15:47(UT) , 2.83 hrs after the burst. We do not detect the reported afterglow counterpart (Guidorzi et al., GCN 16003,Elenin et al., GCN 16005). in our combined images down to the upper limit of 21.8 mag in R band, calibrated by nearby USNO B1.0 R2 mag, at the mean time of 3.22 hrs after the burst. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16013 SUBJECT: GRB 140320B: Swift-XRT detection of the afterglow DATE: 14/03/20 21:57:31 GMT FROM: Claudio Pagani at U of Leicester C. Pagani, K.L. Page, R.L.C. Starling, (U. Leicester) report on behalf of the Swift-XRT team: We have analysed 4 ks of XRT data for the INTEGRAL detected GRB 140320B (Mereghetti et al. GCN Circ. 16004), from 11.6 s to 23.1 ks after the trigger. The data are entirely in Photon Counting (PC) mode. An uncatalogued, fading X-ray source is detected inside the INTEGRAL error circle. Using 3683 s of XRT PC data and 4 UVOT images, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 145.55932, 60.26822 which is equivalent to: RA (J2000): 09 42 14.24 Dec (J2000): +60 16 05.6 with an uncertainty of 1.7 arcsec (radius, 90% confidence). This is consistent with the optical position reported by Guidorzi et al. (GCN 16003) and Elenin et al. (GCN 16005). The light curve can be modelled with a power-law decay with an index of alpha=1.12 (+1.21, -0.05). A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.3 (+0.4, -0.3). The best-fitting absorption column is 6 (+8, -6) x 10^20 cm^-2, consistent with the Galactic value of 2.4 x 10^20 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 2.8 x 10^-11 (3.0 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 1.12, the count rate at T+24 hours will be 7.8 x 10^-3 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.2 x 10^-14 (2.3 x 10^-14) erg cm^-2 s^-1. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16019 SUBJECT: GRB 140320B: Swift/UVOT Upper Limits DATE: 14/03/21 13:02:09 GMT FROM: Samantha Oates at MSSL S. R. Oates (UCL-MSSL) and R. L. C. Starling, (U. Leicester) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 140320B 11975 s after the INTEGRAL trigger (Mereghetti et al., GCN Circ. 16004). No optical afterglow consistent with the XRT position (Pagani et al., GCN Circ. 16013) and the FTN optical position (Guidorzi et al., GCN Circ. 16003) is detected in the initial UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the initial exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white 11975 29408 5864 >23.1 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.02 in the direction of the burst (Schlegel et al. 1998). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 16024 SUBJECT: GRB 140320B: P60 detection of a very red afterglow DATE: 14/03/21 16:39:00 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) and S. B. Cenko (NASA-GSFC) report: The Palomar 60-inch telescope automatically responded to the INTEGRAL trigger for GRB 130420B (Mereghetti et al. GCN 16004) and began taking a series of 60-second exposures in the r, i, and z filters starting at 2014-03-20 09:31:41.744 (7.12 minutes after the trigger). The afterglow candidate reported by Guidorzi et al. (GCN 16003) is well-detected in the initial z-band exposure, weakly detected in the initial i-band exposure, and not detected in the initial r-band exposure. However, a weak r-band detection is recovered by stacking several images. The light curve (in the i- and z-band filters) shows a rise to a peak at around 15 minutes post-trigger, followed by a decline up until the end of our sequence at 1.3 hours after the GRB. Stacking the first 7 exposures in each filter, we estimate magnitudes of: r = 21.29 +/- 0.24 i = 20.07 +/- 0.09 z = 17.97 +/- 0.03 At a mid-UT time of approximately 09:46 in each filter (20 minutes after the trigger). The redder apparent color in i-z compared to r-i may suggest a highly reddened afterglow with host contribution to the r-band, or a reddened afterglow with a very strong 2175 dust feature at z~2.5, or a Lyman break in the i-band with some Lyman-alpha forest blueward (z~5). We encourage further observations, particularly in the NIR. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 29371 SUBJECT: GRB 140320B: Swift-XRT refined Analysis DATE: 21/01/29 14:52:13 GMT FROM: Phil Evans at U of Leicester V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B. Sbarufatti (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB) and C. Pagani report on behalf of the Swift-XRT team: report on behalf of the Swift-XRT team: We have analysed 6.0 ks of XRT data for the INTEGRAL-detected burst GRB 140320B (Pagani et al. GCN Circ. 16013), from 12.0 ks to 29.4 ks after the INTEGRAL trigger. The data are entirely in Photon Counting (PC) mode. The refined XRT position is RA, Dec = 145.5611, +60.2690 which is equivalent to: RA (J2000): 09 42 14.66 Dec(J2000): +60 16 08.3 with an uncertainty of 3.6 arcsec (radius, 90% confidence). This position is 51 arcsec from the INTEGRAL position. We cannot determine at the present time whether the source is fading. A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.4 (+0.4, -0.3). The best-fitting absorption column is 7.2 (+7.1, -4.8) x 10^20 cm^-2, consistent with the Galactic value of 2.4 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 2.8 x 10^-11 (3.8 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 7.2 (+7.1, -4.8) x 10^20 cm^-2 Galactic foreground: 2.4 x 10^20 cm^-2 Excess significance: <1.6 sigma Photon index: 2.4 (+0.4, -0.3) The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00020370. This circular is an official product of the Swift-XRT team.