GRB150120A

This page lists all entries on GRB150120A in GRBweb

Summary Fermi GBM IPN Swift GCN 17310 GCN 17311 GCN 17312 GCN 17313 GCN 17317 GCN 17319 GCN 17323 GCN 17329 GCN 17332 GCN 17334 GCN 17341 GCN 17350 GCN 17358 GCN 17361

Summary table
Variable Value Source
GRB_name_Fermi GRB150120123
T0 2:57:46 UTC GCN_circulars,Swift Det
ra 10.3189° Swift
decl 33.9949° Swift
pos_error 2.33e-04° Swift
T90 3.328 s Fermi_GBM
T90_error 1.382 s Fermi_GBM
T90_start 2:57:46.365 UTC Fermi_GBM
fluence 3.35e-07 erg/cm² Fermi_GBM
fluence_error 2.17e-08 erg/cm² Fermi_GBM
redshift 0.4600
T100 3.693 s
GBM_located False
mjd 57042.123449074075 GCN_circulars,Swift Det
Fermi GBM table
GRB_name_Fermi GRB150120123
trigger_name bn150120123
ra 10.3188°
decl 33.9947°
pos_error 1.02e+01°
datum 2015-01-20
t_trigger 2:57:47.005 UTC
T90 3.328 s
T90_error 1.382 s
T90_start 2:57:46.365 UTC
fluence 3.35e-07 erg/cm²
fluence_error 2.17e-08 erg/cm²
flux_1024 2.95e+00 erg/cm²/s
flux_1024_error 2.35e-01 erg/cm²/s
flux_1024_time -6.40e-01 erg/cm²/s
flux_64 4.79e+00 erg/cm²/s
flux_64_error 1.36e+00 erg/cm²/s
IPN table
GRB_name GRB150120A
ra 10.3083°
decl 33.9833°
pos_error 5.00e-02°
Swift table
GRB_name GRB150120A
t_trigger 2:57:46 UTC
ra 10.3189°
decl 33.9949°
pos_error 2.33e-04°
T90 1.2 s
fluence 1.40e-07 erg/cm²
redshift 0.4600
GCN 17310 table
GRB_name GRB150120A
GCN_number 17310
Detection_method Swift Det
t_trigger 2:57:46 UTC
ra 10.3080°
decl 33.9810°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17310 SUBJECT: GRB 150120A: Swift detection of a possibly-short burst DATE: 15/01/20 03:12:39 GMT FROM: David Palmer at LANL V. D'Elia (ASDC), D. N. Burrows (PSU), M. M. Chester (PSU), N. Gehrels (NASA/GSFC), L. Izzo (URoma/ICRA), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), B. Sbarufatti (INAF-OAB/PSU) and M. H. Siegel (PSU) report on behalf of the Swift Team: At 02:57:46 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 150120A (trigger=627137). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 10.308, +33.981 which is RA(J2000) = 00h 41m 14s Dec(J2000) = +33d 58' 52" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed a single symmetric peak structure with a duration of about 1.5 sec. The peak count rate was ~4000 counts/sec (15-350 keV), at ~0.5 sec after the trigger. The XRT began observing the field at 02:59:02.6 UT, 76.2 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 10.31883, 33.99480 which is equivalent to: RA(J2000) = 00h 41m 16.52s Dec(J2000) = +33d 59' 41.3" with an uncertainty of 3.7 arcseconds (radius, 90% containment). This location is 59 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. We cannot determine whether the source is fading at the present time. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density in excess of the Galactic value (7.86 x 10^20 cm^-2, Willingale et al. 2013), with an excess column of 6 (+5.52/-4.12) x 10^21 cm^-2 (90% confidence). UVOT took a finding chart exposure of 150 seconds with the White filter starting 82 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 2.7'x2.7' sub-image covers 100% of the XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. The 8'x8' region for the list of sources generated on-board covers 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.10. Burst Advocate for this burst is V. D'Elia (delia AT asdc.asi.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.)
GCN 17311 table
GRB_name GRB150120A
GCN_number 17311
Detection_method Swift-XRT Other
ra 10.3187°
decl 33.9944°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17311 SUBJECT: GRB 150120A: Prompt enhanced Swift-XRT position DATE: 15/01/20 03:24:31 GMT FROM: Phil Evans at U of Leicester P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team: Using promptly downlinked XRT event data for GRB 150120A, we find an enhanced XRT position of the afterglow: RA, Dec: 10.3187, 33.9944 which is equivalent to: RA (J2000) = 00 41 16.49 Dec (J2000) = +33 59 39.7 with an uncertainty of 2.2 arcseconds (radius, 90% confidence). Analysis of the promptly available data is online at http://www.swift.ac.uk/sper/627137. Position enhancement is is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular is an official product of the Swift-XRT team.
GCN 17312 table
GRB_name GRB150120A
GCN_number 17312
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17312 SUBJECT: GRB 150120A: P60 optical observations DATE: 15/01/20 04:06:55 GMT FROM: Daniel Perley at Caltech D. A. Perley (Caltech) and S. B. Cenko (NASA/GSFC) report: The Palomar 60-inch robotic telescope began automatic follow-up of the location of possibly-short GRB 150120A (D'Elia et al. GCN 17310) starting at 2015-01-20 03:00:33 UT, approximately 2.7 minutes after the GRB trigger. A sequence of rotating r, i, and z 60-second exposures was acquired, followed by five 180-second exposures in each of r and i bands, under good conditions. No sources are clearly detected inside the enhanced XRT error circle (Evans et al., GCN 17311), either in either individual exposures or in stacks of all 60-second exposures taken in each filter (approximate UT center time 15 minutes post-trigger, limiting magnitudes r>22.5, i>22.4, z>20.9). We detect two faint sources slightly outside the error circle in the stacked frames: Source A: RA=00:41:16.55, dec=+33:59:42.87 Source B: RA=00:41:16.76, dec=+33:59:42.11 Both sources appear to be marginally detected in SDSS pre-imaging and we do not yet have evidence of fading behavior. Further observations and analysis are ongoing. [GCN OPS NOTE(20jan15): Per author's request, the date in the third line was changed from 2015-01-t0 to 2015-01-20.]
GCN 17313 table
GRB_name GRB150120A
GCN_number 17313
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17313 SUBJECT: GRB 150120A: Gemini-North optical imaging DATE: 15/01/20 07:51:01 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (U. Arizona), R. Chornock (Ohio U.) and D. Fox (PSU) report: "We observed the location of the possibly short GRB 150120A (D'Elia et al., GCN 17310) with the Gemini Multi-Object Spectrograph (GMOS) mounted on the Gemini-North 8-m telescope starting on 2015 Jan 20.206 UT (2.0 hr after the BAT trigger). We obtained 1800-sec in each of the riz-bands in 0.5" seeing. Within the enhanced XRT position (Evans, GCN 17311), we do not detect any optical sources in our images. Tied to SDSS, we calculate a 3-sigma limit of r>26.3 AB mag. We clearly detect two sources on the outskirts of the XRT position (Sources A and B from P60 observations; Perley et al., GCN 17312), both of which appear extended in our images. We do not find any evidence for variability of these sources over the duration of our observations. We thank Gemini observers and staff Sabrina Pakzad, Katherine Roth, Joe Burchett, and Rongmon Bordoloi for the quick scheduling and execution of these observations."
GCN 17317 table
GRB_name GRB150120A
GCN_number 17317
Detection_method Swift-XRT Det
ra 10.3189°
decl 33.9948°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17317 SUBJECT: GRB 150120A: Enhanced Swift-XRT position DATE: 15/01/20 10:39:01 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 465 s of XRT Photon Counting mode data and 1 UVOT images for GRB 150120A, 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 = 10.31893, +33.99485 which is equivalent to: RA (J2000): 00h 41m 16.54s Dec (J2000): +33d 59' 41.5" with an uncertainty of 1.8 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401) and Evans et al. (2009, MNRAS, 397, 1177). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 17319 table
GRB_name GRB150120A
GCN_number 17319
Detection_method Fermi GBM Det
t_trigger 2:57:47 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 17319 SUBJECT: GRB 150120A: Fermi GBM observation DATE: 15/01/20 13:49:42 GMT FROM: Andreas von Kienlin at MPE A. von Kienlin (MPE) and E. Burns (UAH) report on behalf of the Fermi GBM Team: "At 02:57:47.00 UT on 20 January 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150120A (trigger 443415470/150120123), which was also detected by the Swift/BAT & XRT (D'Elia et al. 2015, GCN 17310). The GBM on-ground location is consistent with the Swift position. The angle from the Fermi LAT boresight is 98 degrees. The GBM light curve shows a single pulse with a duration (T90) of about 2 s (50-300 keV). The time-averaged spectrum from T0-1.024 s to T0+0.512 s is well fit by a power law function with an exponential high-energy cutoff. The power law index is -1.43 (+0.28/-0.24) and the cutoff energy, parameterized as Epeak, is 130 (+150/-50) keV The event fluence (10-1000 keV) in this time interval is (3.4 +/- 0.8)E-07 erg/cm^2. The 1.024-sec peak photon flux measured starting from T0-0.64 s in the 10-1000 keV band is 3.1 +/- 0.3 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 17323 table
GRB_name GRB150120A
GCN_number 17323
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17323 SUBJECT: GRB 150120A: Swift/UVOT Upper Limits DATE: 15/01/20 19:56:38 GMT FROM: Margaret Chester at PSU M. M. Chester (PSU) and V. D'Elia (ASDC) report on behalf of the Swift/UVOT team: The Swift/UVOT began settled observations of the field of GRB 150120A 83 s after the BAT trigger (D'Elia et al., GCN Circ. 17310). No optical afterglow consistent with the XRT position (Evans et al. GCN Circ. 17317) 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 first finding chart (FC) exposures and subsequent exposures are: Filter T_start(s) T_stop(s) Exp(s) Mag white_FC 83 233 147 >20.6 u_FC 295 545 246 >20.1 white 83 5674 461 >21.0 v 624 6085 432 >19.5 b 550 10198 449 >21.0 u 295 6700 658 >20.6 w1 674 6495 432 >20.5 m2 649 6290 432 >21.1 w2 600 5880 432 >20.5 The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.10 in the direction of the burst (Schlegel et al. 1998).
GCN 17329 table
GRB_name GRB150120A
GCN_number 17329
Detection_method Swift-BAT Det
ra 10.3300°
decl 33.9800°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17329 SUBJECT: GRB 150120A: Swift-BAT refined analysis DATE: 15/01/20 22:50:07 GMT FROM: Amy Lien at GSFC A. Y. Lien (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), V. D'Elia (ASDC), N. Gehrels (GSFC), J. Norris (BSU), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU), J. Tueller (GSFC), T. N. Ukwatta (LANL) (i.e. the Swift-BAT team): Using the data set from T-60 to T+243 sec from the recent telemetry downlink, we report further analysis of BAT GRB 150120A (trigger #627137) (D'Elia, et al., GCN Circ. 17310). The BAT ground-calculated position is RA, Dec = 10.330, 33.980 deg which is RA(J2000) = 00h 41m 19.1s Dec(J2000) = +33d 58' 48.6" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 71%. The mask-weighted light curve shows a single short spike that starts at ~ T-0.4 s, peaks at ~ T+0.4 s, and ends at ~ T+1.0 s. T90 (15-350 keV) is 1.20 +- 0.16 sec (estimated error including systematics). The time-averaged spectrum from T-0.40 to T+0.95 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 1.81 +- 0.18. The fluence in the 15-150 keV band is 1.4 +- 0.2 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T-0.06 sec in the 15-150 keV band is 1.8 +- 0.2 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The burst spectrum appears to be at the softer end of short bursts, which have an average spectral index of 1.2 when fitting with a simple power-law model (Sakamoto et al. 2011). However, the fast fading shown in the X-ray light curve (http://www.swift.ac.uk/xrt_curves/00627137/) suggests that this is indeed a short burst. The lag analysis of this burst does not show a constraining result due to the low intensity. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/627137/BA/
GCN 17332 table
GRB_name GRB150120A
GCN_number 17332
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17332 SUBJECT: GRB 150120A: KAIT Optical Upper Limit DATE: 15/01/21 01:45:57 GMT FROM: Weikang Zheng at UC Berkeley WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) report on behalf of the KAIT GRB team: The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at Lick Observatory, responded to Swift GRB 150120A (D'Elia et al., GCN 17310) starting at 02:59:24 UT, 98 s after the burst. Observations were performed with an automatic sequence in the clear (roughly R), V, and I filters, and the exposure time was 20 s per image. We do not detect any new source in our images within the enhanced XRT error circle (Evans et al., GCN 17317). The typical limiting magnitude of our single clear image is about 18.5 calibrated to USNO B1.0.
GCN 17334 table
GRB_name GRB150120A
GCN_number 17334
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17334 SUBJECT: GRB 150120A: Swift-XRT refined Analysis DATE: 15/01/21 03:12:03 GMT FROM: Phil Evans at U of Leicester J.P. Osborne (U. Leicester), K.L. Page (U. Leicester), C. Pagani (U. Leicester), A. Maselli (INAF-IASFPA), A. Melandri (INAF-OAB), B. Sbarufatti (INAF-OAB/PSU), V. Mangano (PSU), M.C. Stroh (PSU), D.N. Burrows (PSU) and V. D'Elia report on behalf of the Swift-XRT team: We have analysed 5.9 ks of XRT data for GRB 150120A (D'Elia et al. GCN Circ. 17310), from 86 s to 16.2 ks after the BAT trigger. The data are entirely in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Evans et al. (GCN Circ. 17311). The light curve can be modelled with a power-law decay with a decay index of alpha=~4.6. A spectrum formed from the PC mode data can be fitted with an absorbed power-law with a photon spectral index of 2.0 (+/-0.5). The best-fitting absorption column is 6.5 (+4.8, -3.3) x 10^21 cm^-2, in excess of the Galactic value of 7.9 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 4.4 x 10^-11 (7.4 x 10^-11) erg cm^-2 count^-1. A summary of the PC-mode spectrum is thus: Total column: 6.5 (+4.8, -3.3) x 10^21 cm^-2 Galactic foreground: 7.9 x 10^20 cm^-2 Excess significance: 2.8 sigma Photon index: 2.0 (+/-0.5) If the light curve continues to decay with a power-law decay index of ~4.6, the count rate at T+24 hours will be 1.2 x 10^-13 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 5.4 x 10^-24 (9.0 x 10^-24) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00627137. This circular is an official product of the Swift-XRT team.
GCN 17341 table
GRB_name GRB150120A
GCN_number 17341
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 17341 SUBJECT: GRB 150120A: ISON-NM early optical limit DATE: 15/01/21 18:22:16 GMT FROM: Alexei Pozanenko at IKI, Moscow L. Elenin (KIAM), E. Mazaeva (IKI), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of the Swift GRB 150120A (D'Elia et al., GCN 17310) with 0.4-m telescope of ISON-NM observatory in robotic mode starting on Jan., 20 (UT) 02:58:58, i.e. 72 seconds after burst trigger. We obtained 60 unfiltered images of 30 s exposure. We do not detect any source within enhanced XRT error circle (Evans et al., GCN 17317): Date UT start t-T0 Exp. Filter UL (3sigma) (mid.,days) (s) 2015-01-20 02:58:58 0.00227 5*30 Clear 19.0 2015-01-20 02:58:58 0.01950 60*30 Clear 20.2 The photometry is based on nearby SDSS DR9 stars SDSS9_id R_Lupton J004136.43+340051.9 15.61 J004135.94+335950.0 14.56 J004101.23+335851.1 15.84
GCN 17350 table
GRB_name GRB150120A
GCN_number 17350
Detection_method AMI
Circular_text TITLE: GCN CIRCULAR NUMBER: 17350 SUBJECT: GRB 150120A: possible AMI 15 GHz detection DATE: 15/01/26 10:59:48 GMT FROM: Gemma Anderson at U of Oxford G. E. Anderson, R. P. Fender, T. D. Staley (University of Oxford), A. J. van der Horst (George Washington University), A. Rowlinson (CASS) We observed the position of the possibly-short burst GRB 150120A (DElia et al., GCN 17310) at 15 GHz with the Arcminute Microkelvin Imager (AMI-LA) starting on 2015 Jan 21.690 to 21.856 UT, corresponding to 1.6 days post-burst. On this date we possibly detected a ~4 sigma radio source with flux 0.17 +/- 0.04 mJy at the position RA(J200): 0:41:16.72 Dec(J2000): 33:59:55.4 with a positional uncertainty of ~10 arcseconds. This is ~14 arcseconds from the best XRT position quoted by Evan et al., GCN 17317. An earlier and later observation was conducted on 2015 Jan 20.475 to 20.559 UT and 2015 Jan 22.666 to 22.832 UT, corresponding to 0.4 and 2.5 days post-burst, yielding 3 sigma flux upper limits of 0.19 mJy and 0.10 mJy, respectively. Further AMI monitoring is planned. We thank the AMI staff for scheduling these observations.
GCN 17358 table
GRB_name GRB150120A
GCN_number 17358
Detection_method Optical
redshift 0.4600
Circular_text TITLE: GCN CIRCULAR NUMBER: 17358 SUBJECT: GRB 150120A: Gemini-N imaging and host redshift DATE: 15/01/28 22:40:07 GMT FROM: Ryan Chornock at Ohio U R. Chornock (Ohio University) and W. Fong (University of Arizona) report: We re-imaged the field of the possibly-short GRB 150120A (D'Elia et al., GCN 17310) with the Gemini Multi-Object Spectrograph (GMOS) mounted on the Gemini-North 8-m telescope starting on 2015 Jan 22.284 UT (2.16 days post-burst and 49.8 hr after our first Gemini observations; Fong et al., GCN 17313). We obtained a total of 2160s of observations in r-band in 1.0" seeing at an airmass of 1.6. Image subtraction using the ISIS package reveals no residuals in or around the enhanced XRT position (Evans et al., GCN 17317). Based on the 3-sigma limit of the second epoch, which is not deep as our first epoch due to poorer conditions, we place a limit of r(AB)>25.0 mag on the optical afterglow of GRB 150120A at 2.0 hr post-burst. We note that the enhanced XRT position (Evans et al., GCN 17317) shifted relative to the prompt enhanced XRT position (Evans, GCN 17311) and now encompasses Source A of Perley & Cenko (GCN 17312), while Source B is now just outside the XRT error circle. We placed a spectroscopic slit across both Sources A and B and obtained a pair of 900s GMOS spectra on 2014 Jan. 27 with the R400 grating (range 4900-9200 Angs). Both galaxies exhibit nebular emission lines (H-beta, [O III]) at the same common redshift of z=0.460. We thank the staff at Gemini for their assistance scheduling and performing these observations.
GCN 17361 table
GRB_name GRB150120A
GCN_number 17361
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17361 SUBJECT: GRB 150120A: 9.8 GHz VLA upper limit DATE: 15/01/30 00:44:17 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (U. Arizona) reports: "We observed the field of the possibly-short GRB 150120A (D'Elia et al., GCN 17310) with the Karl G. Jansky Very Large Array (VLA) beginning on 2015 Jan 21.027 UT (21.7 hr post-burst) at a mean frequency of 9.8 GHz. In 70 min of observations, we do not detect any radio source within or around the enhanced XRT position (Evans et al., GCN 17317). In addition, we do not detect any radio source within or near the position of the possible AMI source at 15 GHz (Anderson et al., GCN 17350). We therefore place a 3-sigma limit of ~30 microJy on the 9.8 GHz radio afterglow of GRB 150120A at 21.7 hr after the burst. We thank the VLA staff for quickly executing these observations."