//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17501 SUBJECT: GRB 150220A: Swift ToO observations DATE: 15/02/23 21:35:29 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 IPN GRB 150220A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/ToO_GRBs/00020484 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 IPN 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: 17502 SUBJECT: IPN Triangulation of GRB 150220A DATE: 15/02/24 15:29:11 GMT FROM: Dmitry Svinkin at Ioffe Institute K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team, I. G. Mitrofanov, D. Golovin, M. L. Litvak, and A. B. Sanin, on behalf of the HEND-Odyssey GRB team, S. Golenetskii, R. Aptekar, V. Pal'shin, D. Frederiks, D. Svinkin, 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, W. Boynton, C. Fellows, K. Harshman, H. Enos, and R. Starr, on behalf of the GRS-Odyssey GRB team, report: A long-duration GRB 150220A has been observed by Fermi (GBM trigger 446134898), Konus-Wind, Mars-Odyssey (HEND), and MESSENGER (GRNS), so far, at about 51696 s UT (14:21:36). We have triangulated it to a preliminary, 3 sigma error box whose coordinates are: --------------------------------------------- RA(2000), deg Dec(2000), deg --------------------------------------------- Center: 135.496 (09h 01m 59s) -1.597 ( -1d 35' 49") Corners: 135.673 (09h 02m 42s) -1.932 ( -1d 55' 54") 135.354 (09h 01m 25s) -2.064 ( -2d 03' 51") 135.322 (09h 01m 17s) -1.262 ( -1d 15' 42") 135.642 (09h 02m 34s) -1.124 ( -1d 07' 25") --------------------------------------------- The error box area is 943 sq. arcmin, and its maximum dimension is 59 arcmin (the minimum one is 19.6 arcmin). The Sun distance was 158 deg. This box may be improved. A triangulation map is posted at http://www.ioffe.ru/LEA/GRBs/GRB150220_T51704/IPN/ A Swift ToO observation has been scheduled (Evans, GCN Circ. 17501). The time history and spectrum will be given in forthcoming GCN Circulars. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17503 SUBJECT: Konus-Wind observation of GRB 150220A DATE: 15/02/24 15:34:07 GMT FROM: Dmitry Svinkin at Ioffe Institute S. Golenetskii, R. Aptekar, D. Frederiks, V. Pal'shin, P. Oleynik, M. Ulanov, D. Svinkin, A. Tsvetkova, A. Lysenko, and T. Cline on behalf of the Konus-Wind team, report: The long-duration GRB 150220A (IPN triangulation: Hurley et al., GCN Circ. 17502) triggered Konus-Wind at T0=51704.661 s UT (14:21:44.661). The burst light curve shows two emission episodes separated by ~100 s with a total duration of ~160 s. The emission is seen up to ~2 MeV. The Konus-Wind light curve of this GRB is available at http://www.ioffe.ru/LEA/GRBs/GRB150220_T51704/ As observed by Konus-Wind, the burst had a fluence of 3.00(-0.29,+0.37)x10^-5 erg/cm2, and a 64-ms peak flux, measured from T0+13.568 s, of 4.61(-1.05,+1.07)x10^-6 erg/cm2/s (both in the 20 keV - 10 MeV energy range). The time-averaged spectrum of the burst (measured from T0 to T0+147.712 s) is best fit in the 20 keV - 3 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.86(-0.29,+0.34) and Ep = 211(-34,+55) keV (chi2 = 49/64 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.2 (chi2 = 48/63 dof) The spectrum near the maximum count rate (measured from T0+8.448 to T0+16.640 s) is best fit in the 20 keV - 3 MeV range by a power law with exponential cutoff model: dN/dE ~ (E^alpha)*exp(-E*(2+alpha)/Ep) with alpha = -0.98(-0.17,+0.19) and Ep = 225(-28,+38) keV (chi2 = 54/64 dof). Fitting by a GRB (Band) model yields the same alpha and Ep, and an upper limit on the high energy photon index: beta < -2.6 (chi2 = 55/63 dof) All the quoted errors are at the 90% confidence level. All the quoted values are preliminary. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17504 SUBJECT: GRB 150220A: Swift-XRT observations DATE: 15/02/24 15:39:26 GMT FROM: Andrea Melandri at INAF-OAB V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), A. Maselli (INAF-IASFPA), D.N. Burrows (PSU), J.A. Kennea (PSU), B. Sbarufatti (INAF-OAB/PSU), A.P. Beardmore (U. Leicester), A. Amaral-Rogers (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 IPN-detected burst GRB 150220A, collecting 3.0 ks of Photon Counting (PC) mode data between T0+284.9 ks and T0+300.7 ks. Three uncatalogued X-ray sources have been detected, however none of them is above the RASS limit or shows definitive signs of fading. Therefore, at the present time we cannot identify which, if any, is the afterglow. Details of these sources are given below: Source 2: RA (J2000.0): 135.3781 = 09:01:30.74 Dec (J2000.0): -1.6408 = -01:38:27.0 Error: 6.2 arcsec (radius, 90% conf.) Count-rate: (6.8 +/- 1.9)e-3 ct s^-1 Flux: (3.26 +/- 0.93)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 3: RA (J2000.0): 135.5356 = 09:02:8.55 Dec (J2000.0): -1.6164 = -01:36:59.1 Error: 4.9 arcsec (radius, 90% conf.) Count-rate: (4.7 +/- 1.7)e-3 ct s^-1 Flux: (2.31 +/- 0.81)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV) Source 7: RA (J2000.0): 135.4432 = 09:01:46.37 Dec (J2000.0): -1.6372 = -01:38:13.9 Error: 7.1 arcsec (radius, 90% conf.) Count-rate: (3.3 [+1.6, -1.3])e-3 ct s^-1 Flux: (6.5 [+3.1, -2.5])e-14 erg cm^-2 s^-1 (observed, 0.3-10 keV) Four catalogued sources were also detected. 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/00020484. This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17505 SUBJECT: GRB 150220A: Fermi GBM observation DATE: 15/02/24 17:40:09 GMT FROM: Oliver Roberts at UCD/Fermi O.J. Roberts (UCD) and C. Meegan (UAH) report on behalf of the Fermi GBM Team: "At 14:21:35.60 UT on the 20th of February 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150220A (trigger 446134898 / 150220598), which was also detected by IPN (Hurley et al. 2015, GCN 17502) and Konus-Wind (Golenetskii et al. 2015, GCN 17503 ). The GBM on-ground location is consistent with the IPN triangulated position. The angle from the Fermi LAT boresight is 78 degrees. The GBM light curve shows three pulses occurring over two main emission episodes. These episodes begin at about T0-9.5s and T0+105s respectively. The duration (T90) of the entire light curve is about 145s (50-300 keV). The time-averaged spectrum of both emission episodes, from T0-9.5s to T0+37.6s and from T0+104.7s to T0+162.6s is best fit by a power law function with an exponential high-energy cutoff. The power law index is -1.02 +/- 0.03 and the cutoff energy, parameterised as Epeak, is 192.3 +/- 9.5 keV. The event fluence (10-1000 keV) in this time interval is (2.72 +/- 0.07)E-05 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0+17.9 s in the 10-1000 keV band is 15.7 +/- 0.4 ph/s/cm^2. A Band function fits the spectrum equally well with Epeak = 170.8 +/- 12.8 keV, alpha = -0.97 +/- 0.05 and beta = -2.41 +/- 0.21. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog." //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17532 SUBJECT: GRB 150220A: further Swift-XRT observations DATE: 15/03/02 16:17:48 GMT FROM: Andrea Melandri at INAF-OAB A. Melandri (INAF/OAB) reports on behalf of the Swift-XRT team: Swift-XRT observed again the field of the IPN GRB 150220A (Hurley et al. GCN 17502; Roberts & Meegan GCN 17505). The observation +started on 2015-02-27 at 14:41 UT, i.e. ~7 days after the burst detection. For the three sources detected by Swift-XRT, reported in D'Elia et al. (GCN 17504) we did not find any evidence for fading. In +particular: Source 2: Epoch1: (6.8 +/- 1.9)e-3 ct s^-1 Epoch2: <5.4e-3 ct s^-1 (3sigma upper limit) Source 3: Epoch1: (4.7 +/- 1.7)e-3 ct s^-1 Epoch2: <4.1e-3 ct s^-1 (3sigma upper limit) Source 7: Epoch1: (3.3 +/- 1.7)e-3 ct s^-1 Epoch2: <3.0e-3 ct s^-1 (3sigma upper limit) This circular is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17589 SUBJECT: GRB 150220A, the review of the sky area in plate archives DATE: 15/03/16 14:22:03 GMT FROM: Valentyna Golovnya at Main Astro Obs,Kyiv V. V. Golovnya, V. M. Andruk (Main Astro Obs., Kyiv) report: We have undertaken the review of the sky area of GRB 150220A (P.A. Evans, GCN Circ. 17501) on astronegatives, collected in Ukrainian plate archive (1976-1996). All the plates with the possible object appearance are digitized using Microtek ScanMaker 9800XL TMA and Epson Expression 10000XL flatbed scanner and the images have been placed into Golosiiv Plate Archive database DBGPA with open access to them. 2 objects have been found on the plate GUA040C002183 (EPOCH=1993.2192). Scanning and processing methods were described in [1-3]. The coordinates and B magnitudes were obtained in the system of TYCHO-2 catalog: N of Obj. MagTyc RA(J2000) Dec(J2000) 1 (26646) 16.17 09h02m12.961s -01d40’24.457” 2 (26663) 15.96 09 02 13.504 -01 39 51.118 Rms RA=0.093”, rms Dec=0.099”, rms MagTyc=0.21 The list of plates is given in the table: yyyymmdd/TimeUT-- ---Plates---- Exp. –Mag --USNO-A2---- 19830119/20:30:49 TAS040A000485 28.0 16.4 0825-06684950 19900323/19:14:27 GUA040C003371 12.5 15.6 0825-06686191 19930319/19:23:16 GUA040C002183 21.8 15.7 0825-06683708 Plates: GUA040C –The plates archive identifier of DWA (D/F=400/2000, M=103”/mm) of the Ukrainian NAS Main Astro obs. (Marsden's number - 83) the plate number [4]. TAS040A -the plates archive identifier of DAZ (D/F=400/3000, M=68.8”/mm) of the Tashkent Astro obs. (Marsden's number - 186) the plate number [4]. Exp. - Duration of the maximum exposure (minutes). Mag - Limited Bmag, derived in the 13 minutes area around the position: RA(J2000): 09h 01m 51.6s, Dec(J2000): -01d 38’ 03”. USNO-A2 - Comparison star. The preview images of 3 areas together with the 13 min. of arc area from Aladin can be found in “http://gua.db.ukr-vo.org/img/grb/150220A/index.html”. The images with full resolution are available via e-mail on demand. References: 1. Andruk V.М., Butenko G.Z., Yatsenko A.I.: 2010, Kinematics and Physics of Celestial Bodies, 26/3, 75-81. 2. V.Golovnya, V.Andruk, A.Yatsenko: 2010, Journal of Physical Studies, 14, N2, 2902. 3. Yatsenko A.I., Andruk V.N., Golovnia V.V., Pakuliak L.K., Ivanov G.A.: 2011, Kinematics and Physics of Celestial Bodies, 27/3, 49-59. 4. L.Pakuliak: DBGPA V2.0, “http://gua.db.ukr-vo.org”. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 17645 SUBJECT: GRB 150220A: Optical observations at Kyiv comet station DATE: 15/03/26 13:05:37 GMT FROM: Valentyna Golovnya at Main Astro Obs,Kyiv Ya. Romanyuk (Main Astro Obs., Kyiv), A. Baransky (Astr. Obs. of Kyiv University), I. Kulyk, V. Golovnya, V. Andruk (Main Astro Obs., Kyiv) report: We observed the field of GRB 150220A (P.A. Evans, GCN Circ. 17501) with 0.7-m f/4 reflector of Kyiv comet station (Marsden's number – 585). The telescope is equipped with CCD, 10271056 pixels with a scale of 0.95"/px. We obtained 2160sec images in R-filter on Mar., 10, 2015, from (UTC) 19:08:15 to 19:44:09. Purpose of our observations was not to search for the afterglow candidate. We would like to find two objects referred to in (V. V. Golovnya, V. M. Andruk, GCN 17589), which was found on the old archive photographic plates in close vicinity of the position of source '1SXPS J090208.3-014021': RA,Dec(J2000)= 09h02m12.961s -01d40'24.457" and 09 02 13.504 -01 39 51.118 The preview of archive photographic plates can be found at 'http://gua.db.ukr-vo.org/img/grb/150220A/index.html' The CCD images were processed with the standard technique and co-added together to create a frame with higher signal/noise ratio. We did not find above mentioned objects on the CCD, but we confirmed some of the positions reported early by P.A. Evans (GCN 17501). The following table gives the positions listed by Evans, as well as the positions some of the objects calculated from the CCD. Position from P. A. Evans, GCN 17501 our work RA(J2000) Dec(J2000) RA(J2000) Dec(J2000) 1) 09h 01m 31.65s -01° 39' 07.6" -------- outside our field 2) 09h 01m 30.74s -01° 38' 27.0" -------- outside our field 3) 09h 02m 08.55s -01° 36' 59.1" -------- 09h 02m 08.1s -01° 36' 35" 4) 09h 02m 08.90s -01° 40' 20.1" -------- extremely faint 5) 09h 01m 28.27s -01° 39' 06.3" -------- outside our field 6) 09h 02m 25.29s -01° 41' 14.9" -------- 09h 02m 25.3s -01° 41' 15" 7) 09h 01m 46.37s -01° 38' 13.9" -------- 09h 01m 46.4s -01° 38' 14"