//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18859 SUBJECT: GRB 160113A: iPTF P48 Observations and Optical Transient Candidates DATE: 16/01/13 20:43:09 GMT FROM: Leo Singer at GSFC/iPTF L. P. Singer (NASA/GSFC), V. Bhalerao (IUCAA), S. B. Cenko (NASA/GSFC), and M. M. Kasliwal (Carnegie) report on behalf of a larger collaboration: Fermi GBM detected GRB 160113A (trigger 474370354 / bn160113398) at 2016-01-13 09:32:30.52. At 10:31:39, about 1 hour after the burst, we began searching for optical counterparts using the Palomar 48-inch Oschin telescope (P48). We imaged 18 fields covering an area of 133 deg^2 in the 1-sigma statistical+systematic region of the final Fermi GBM localization. We estimate a 78% prior probability that these fields contain the true location of the source. Sifting through candidate variable sources using image subtraction and standard iPTF vetting procedures, we detected the following optical transient candidates: name RA Dec mag t Notes ---------------------------------------------------------------------------- Hostless ---------------------------------------------------------------------------- iPTF15flo 192.718034 +12.070614 20.29 1.99 iPTF15fls 187.113722 +7.078087 20.59 2.42 near elliptical galaxy at z=0.175 ---------------------------------------------------------------------------- Hosts with spectroscopic redshifts ---------------------------------------------------------------------------- iPTF15flq 179.356225 +11.915619 20.02 2.10 z=0.165 iPTF15flm 191.925125 +13.140841 19.99 1.82 z=0.155 iPTF15fly 180.870452 +13.440016 19.41 2.10 z=0.090 iPTF15fln 192.218146 +15.660583 20.23 1.88 z=0.081, possibly fading iPTF15flp 181.050555 +11.765386 19.28 1.52 z=0.296, BL Lac (Veron+ 2010) ---------------------------------------------------------------------------- Hosts with photometric redshifts ---------------------------------------------------------------------------- iPTF15flk 184.180492 +13.204215 20.66 1.58 z=0.382 iPTF15flr 181.775607 +9.400882 19.03 2.19 z=0.087 ---------------------------------------------------------------------------- Possibly stellar ---------------------------------------------------------------------------- iPTF15flx 181.613083 +13.008351 20.33 1.52 Times are in hours since the GBM trigger. Magnitudes are in the Mould R filter and in the AB system, calibrated with respect to point sources in SDSS as described in Ofek et al. (2012, http://dx.doi.org/10.1086/664065). We have scheduled all of the above sources for multi-band photometry on the robotic Palomar 60" telescope (P60) tonight. We have requested Swift target-of-opportunity observations of iPTF15flo. Further observations of the above candidates, particularly iPTF15flo and iPTF15fls, are encouraged to determine their nature and if one of them is the optical afterglow of the GRB. The diagram http://asd.gsfc.nasa.gov/Leo.Singer/Fermi474370354.pdf shows the locations of our candidates and the P48 fields in relation to the Fermi GBM 1- and 2-sigma statistical+systematic contours. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18860 SUBJECT: GRB 160113A: Swift ToO observations DATE: 16/01/13 22:31:17 GMT FROM: Phil Evans at U of Leicester P. A. Evans (U. Leicester) reports on behalf of the Swift team: Swift has initiated a ToO observation of the Fermi/GBM GRB 160113A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020594 Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. These are not necessarily related to the Fermi/GBM event. Any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration. Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8). This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18861 SUBJECT: GRB 160113A: Fermi GBM detection DATE: 16/01/14 00:57:55 GMT FROM: Eric Burns at U of Alabama O.J. Roberts (UCD) and E. Burns(UAH) report on behalf of the Fermi GBM Team: "At 09:32:30.52 UT on 13 January 2016, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 160113A (trigger 474370354 / 160113398). The on-ground calculated location, using the GBM trigger data, is RA = 187.3, DEC = 11.5, with an uncertainty of 1.2 degrees (radius, 1-sigma containment, statistical only; there is additionally a systematic error which we have characterized as a core-plus-tail model, with 90% of GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg systematic error. [Connaughton et al. 2015, ApJS, 216, 32] ). All of the optically variable sources detected by iPTF (Singer, GCN 18859) are contained in the uncertainty region surrounding the final location. The angle from the Fermi LAT boresight at the GBM trigger time is 98 degrees. The GBM light curve consists of a smaller peak between T-5 and T+10 followed by a bright peak from T+20 to about T+60 with a duration (T90) of about 25 s (50-300 keV). The time-averaged spectrum from T0+25.60 s to T0+51.20 s is best fit by a Band function with Epeak = 98 +/- 1 keV, alpha = -0.40 +/- 0.03, and beta = -3.16 +/- 0.11 The event fluence (10-1000 keV) in this time interval is (3.12 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0+31.51 s in the 10-1000 keV band is 27.7 +/- 0.5 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18862 SUBJECT: GRB 160113A: Swift-XRT observations DATE: 16/01/14 10:15:05 GMT FROM: Sarah Gibson at U.of Leicester A.P. Beardmore (U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), A. Maselli (INAF-IASFPA), L.M. McCauley (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), S.L. Gibson (U. Leicester) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team: Swift-XRT has performed follow-up observations of the Fermi/GBM-detected burst GRB 160113A (Roberts et al. GCN Circ. 18861), collecting 2.7 ks of Photon Counting (PC) mode data between T0+46.7 ks and T0+53.0 ks. The pointing was aimed at the optical transient candidate iPTF15flo (Singer et al. GCN Circ. 18859). No X-ray sources have been detected inside or close to the iPTF15flo error region. The 3-sigma upper limit at the iPTF15flo position is 0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of 2.1e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum). The results of the XRT-team automatic analysis of the XRT observations, including a position-specific upper limit calculator, are available at http://www.swift.ac.uk/ToO_GRBs/00020594. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18871 SUBJECT: IPN Triangulation of GRB 160113A DATE: 16/01/15 18:43:15 GMT FROM: Dmitry Svinkin at Ioffe Institute K. Hurley, on behalf of the IPN, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, S. Golenetskii, R. Aptekar, D. Frederiks, D. Svinkin, A. Kozlova, and T. Cline on behalf of the Konus-Wind team, V. Connaughton, M. S. Briggs, C. Meegan, V. Pelassa, and A. Goldstein, on behalf of the Fermi GBM team, S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of the Swift-BAT team, A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, and W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: The long-duration GRB 160113A has been detected by Fermi (GBM: Roberts and Burns, GCN Circ. 18861), Konus-Wind, INTEGRAL (SPI-ACS), Swift (BAT), and Mars-Odyssey (HEND), so far, at about 34350 s UT (09:32:30). The burst was outside the coded field of view of the BAT. We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Corners: 197.219 (13h 08m 52s) +18.468 (+18d 28' 03") 197.479 (13h 09m 55s) +19.448 (+19d 26' 51") 177.907 (11h 51m 38s) -19.867 (-19d 52' 02") 178.597 (11h 54m 23s) -19.094 (-19d 05' 38") --------------------------------------------- The error box area is 17.0 sq. deg, and its maximum dimension is 42.8 deg (the minimum one is 45 arcmin). The Sun distance was about 100 deg. This box may be improved. The intersection of the box with the 3 sigma contours of the GBM ground position was outside of the BAT coded FoV. There is only one OT candidate, iPTF15fln (Singer et al., GCN Circ. 18859), consistent with the box; the candidate was marked as possibly fading. The distance between the narrowest annulus (Konus-HEND annulus with 3 sigma half width of 0.375 deg) center line and the iPTF15fln is 5.2 arcmin, supporting the association of the transient and the GRB. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB160113_T34379/IPN/ The Konus-Wind time history and spectrum will be given in a forthcoming GCN Circular. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 18876 SUBJECT: Konus-Wind observation of GRB 160113A DATE: 16/01/17 14:23:27 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, D. Frederiks, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A.Lysenko, A. Kozlova, and T. Cline, on behalf of the Konus-Wind team, report: The long-duration GRB 160113A (Fermi-GBM detection: Roberts & Burns, GCN 18861; IPN triangulation: Hurley et al., GCN 18871) triggered Konus-Wind at T0=34379.515 s UT (09:32:59.515). The light curve shows a smooth pulse in the interval from ~T0-5 s to ~T0+20 s, preceded by a much weaker pulse around ~T0-28 s. The emission is seen up to ~7 MeV. As observed by Konus-Wind, the burst had a fluence of 2.4(-0.1,+0.1)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+5.184 s, of 4.0(-0.3,+0.4)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum (measured from T0 to T0+21.248 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.51 (-0.15,+0.17), the high energy photon index beta = -3.55 (-0.83,+0.37), the peak energy Ep = 97 (-4,+4) keV, chi2 = 71.7/97 dof. The spectrum near the peak count rate (measured from T0+0.256 to T0+8.192 s) is best fit in the 20 keV - 15 MeV range by the GRB (Band) function with the following model parameters: the low-energy photon index alpha = -0.24 (-0.19,+0.24), the high energy photon index beta = -3.36 (-0.71,+0.39), the peak energy Ep = 130 (-9,+8) keV, chi2 = 71.5/97 dof. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB160113_T34379/ All the quoted errors are at the 90% confidence level. All the quoted values are preliminary.