GRB150101B

This page lists all entries on GRB150101B in GRBweb

Summary Fermi GBM IPN Swift GCN 17276 GCN 17278 GCN 17285 GCN 17288 GCN 17321 GCN 17333 GCN 17431 GCN 22889

Summary table
Variable Value Source
GRB_name_Fermi GRB150101641
T0 15:23:00 UTC Swift
ra 188.0205° Swift
decl -10.9336° Swift
pos_error 2.33e-04° Swift
T90 0.08 s Fermi_GBM
T90_error 0.928 s Fermi_GBM
T90_start 15:23:34.452 UTC Fermi_GBM
fluence 2.38e-07 erg/cm² Fermi_GBM
fluence_error 1.51e-08 erg/cm² Fermi_GBM
redshift 0.1340 GCN_circulars,Swift Other
T100 34.532 s
GBM_located False
mjd 57023.64097222222 Swift
Fermi GBM table
GRB_name_Fermi GRB150101641
trigger_name bn150101641
ra 188.0000°
decl -10.9561°
pos_error 1.20e+01°
datum 2015-01-01
t_trigger 15:23:34.468 UTC
T90 0.08 s
T90_error 0.928 s
T90_start 15:23:34.452 UTC
fluence 2.38e-07 erg/cm²
fluence_error 1.51e-08 erg/cm²
flux_1024 1.27e+00 erg/cm²/s
flux_1024_error 2.01e-01 erg/cm²/s
flux_1024_time -1.28e-01 erg/cm²/s
flux_64 1.05e+01 erg/cm²/s
flux_64_error 1.35e+00 erg/cm²/s
IPN table
GRB_name GRB150101B
ra 188.0417°
decl -10.9500°
pos_error 5.00e-02°
redshift 0.1340
Swift table
GRB_name GRB150101B
t_trigger 15:23:00 UTC
ra 188.0205°
decl -10.9336°
pos_error 2.33e-04°
T90 0.018 s
fluence 2.30e-08 erg/cm²
redshift 0.0930
GCN 17276 table
GRB_name GRB150101B
GCN_number 17276
Detection_method Fermi GBM Det
t_trigger 15:23:34.470 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 17276 SUBJECT: GRB 150101B: Fermi GBM detection DATE: 15/01/04 05:56:32 GMT FROM: Matthew Stanbro at UAH/Fermi Matthew Stanbro (UAH) reports on behalf of the Fermi GBM Team: "At 15:23:34.47 UT on 01 January 2015, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 150101B (trigger 441818617 / 150101641). which was also detected by the BAT during a slew (Cummings et al. 2015, GCN 17267). The GBM on-ground location is consistent with the Swift/BAT position. The angle from the Fermi LAT boresight is 44 degrees. The GBM light curve consists of one peak with a duration (T90) of about 0.08 s (50-300 keV). The time-averaged spectrum from T0-0.016 s to T0+0.064 s is best fit by a simple power law function with index -1.70 +/- 0.09. The event fluence (10-1000 keV) in this time interval is (1.09 +/- 0.14)E-07 erg/cm^2. The 64-ms peak photon flux measured starting from T0+0.00 s in the 8-1000 keV band is 10.48 +/- 1.35 ph/s/cm^2. The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
GCN 17278 table
GRB_name GRB150101B
GCN_number 17278
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 17278 SUBJECT: GRB 150101B: potential host galaxy redshift by GTC DATE: 15/01/04 12:07:07 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia A. J. Castro-Tirado (IAA-CSIC, ISA-UMA), R. Sanchez-Ramirez, J. Gorosabel (IAA-CSIC, UPV/EHU) and R. Scarpa (GTC), on behalf of a larger collaboration, report: Following the detection of the short-duration GRB 150101B by Swift/BAT (Cummings et al. 2015, GCNC 17267) and Fermi (Stanbro et al. GCNC 17276), we have obtained an optical spectrum with the 10.4 m GTC (+OSIRIS) starting on Jan 4, 5:41 UT (i.e. 38.1 hr postburst), covering the 3700-10000 A wavelength range, under poor weather conditions (passing clouds) and bad (>2.5”) seeing. The slit included the position of the proposed optical afterglow (Fong et al. GCNC 17271) as well as the putative host galaxy also detected by Swift/UVOT (Cummings et al. GCNC 17258). We detect a faint emission line consistent with [OII] at z = 0.093, which we propose to be that of the potential host galaxy. If the association is confirmed, this would make of GRB 150101B the nearest short-duration GRB found to date. Observations at all wavelengths are encouraged.
GCN 17285 table
GRB_name GRB150101B
GCN_number 17285
Detection_method Swift Other
redshift 0.1340
Circular_text TITLE: GCN CIRCULAR NUMBER: 17285 SUBJECT: GRB 150101B / Swift J123205.1-105602: X-ray counterpart is likely an AGN DATE: 15/01/06 18:57:28 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (U. Arizona), E. Berger (Harvard) and B. J. Shappee (Carnegie) report: "We re-observed the location of the short soft GRB 150101B (Cummings; GCN 17267) with Magellan/IMACS starting on 2015 Jan 04.30 UT (2.66 days post-burst and 24.0 hr after our initial observations; Fong et al., GCN 17271). We obtained 10x120-sec of r-band observations in 0.82" seeing at an airmass of 1.5. Digital image subtraction with our first set of observations using the ISIS package reveals no variable sources within or near the location of the XRT source ( http://www.swift.ac.uk/xrt_positions/00020464/). This indicates that the unresolved optical source identified by Fong et al., (GCN 17271) is unrelated to the GRB. Using the redshift of z=0.134 (Levan et al. GCN 17281) for the galaxy 2MASX J12320498-1056010 which coincides with the XRT position, we find that the XRT source has an X-ray luminosity of LX ~ 3e43 erg/s, and remains steady from 1.7 to 4.0 days post-burst (http://www.swift.ac.uk/xrt_curves/00020464/). The galaxy also coincides with a bright radio source in the NRAO VLA Sky Survey (Condon et al., 1998, AJ, 115, 1693), with a luminosity at 1.4 GHz of nuLnu ~ 6e39 erg/s. If due to star formation, this requires SFR ~ 150 solar masses per year, which contradicts the lack of emission lines from the galaxy (Levan et al. GCN 17281). On the other hand, the radio and X-ray luminosities match the properties of low-luminosity AGN with Lbol/LEdd < 10^-3 (e.g., Ho 2008, ARA&A, 46, 475). This interpretation is also supported by the large NIR luminosity and very red UV-NIR color (from GALEX and 2MASS). We therefore conclude that 2MASX J12320498-1056010 is a low-luminosity AGN, and that the XRT source is unrelated to GRB 150101B."
GCN 17288 table
GRB_name GRB150101B
GCN_number 17288
Detection_method VLA Det
ra 188.0341°
decl -10.9373°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17288 SUBJECT: GRB 150101B / Swift J123205.1-105602: 9.8 GHz VLA observations DATE: 15/01/09 16:06:35 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (U. Arizona) reports on behalf of a larger collaboration: "We observed the field of the short/soft GRB 150101B (Cummings; GCN 17267) with the Karl G. Jansky Very Large Array (VLA) beginning on 2015 Jan 07.378 UT (5.73 days post-burst) at a mean frequency of 9.8 GHz. These observations are contemporaneous with the WSRT observations at 4.9 GHz (van der Horst et al.; GCN 17286) and cover the BAT position (90% containment). In 1 hour of observations, we detect two sources within the BAT position also identified by WSRT. The first source coincides with the galaxy 2MASX J12320498-1056010, the XRT position (Cummings et al.; GCN 17268) and the bright source at 4.9 GHz (van der Horst et al.; GCN 17286). The 9.8 GHz flux density is 3.15 +/- 0.02 milliJy which translates to nuLnu ~ 1.5e40 erg/s (at z=0.134; Levan et al.; GCN 17281), consistent with the interpretation that this source is an AGN (Fong et al.; GCN 17285). The second, fainter source is located at: RA(J2000) = 12:32:08.19 Dec(J2000) = -10:56:14.2 with an uncertainty of 1" in each coordinate, and coincides with the WSRT position (van der Horst et al.; GCN 17286). This source has a 9.8 GHz flux density of 0.45 +/- 0.01 milliJy. Assuming a single power law between 4.9 and 9.8 GHz, we calculate a spectral index of -1.13 +/- 0.25 for this source. We note that there is no optical source at this position in our Magellan r-band observations (Fong et al.; GCN 17285) or in deeper r-band imaging we obtained with Gemini-South/GMOS (17x90-sec) at 5.67 days post-burst. We do not detect any other radio sources within the BAT position to a 3-sigma limit of 27 microJy. We thank the VLA staff for quickly executing these observations."
GCN 17321 table
GRB_name GRB150101B
GCN_number 17321
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17321 SUBJECT: GRB 150101B/Swift J123205.1-105602, deep VLT observations DATE: 15/01/20 15:31:06 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (U. Warwick), J. Hjorth (DARK/NBI), N.R. Tanvir, K. Wiersema (U. Leicester), A.J. van der Horst (George Washington University) report on behalf of a larger collaboration: "We obtained further deep optical observations of the field of GRB 150101B/Swift J123205.1-105602 (Cummings; GCN17267, 17268) using the VLT and FORS2, on the 19 & 20 Jan 2015. At this epoch 1200s of observations were taken in both g, R and I, in dark time with seeing between 0.6-0.8". Within these deep images we locate a faint counterpart to the radio source identified by van der Horst et al. (GCN 17286) and Fong et al. (GCN 17288). It appears to be a marginally extended source with R~25 (calibrated against USNO), and to be relatively blue given its non-detection in the IR. However, its persistent radio emission implies it is likely not related to the outburst. We do not see any object at the location of the putative optical counterpart identified in Magellan imaging by Fong et al. (GCN 17271), whose location is consistent with the presence of an X-ray source with L_X ~ 1e43 ergs/s in Chandra observations (Troja et al. GCN 17289). Given our detection of the possible radio counterpart above, we conclude that these images are deeper than those reported previously by Fong et al. (GCN 17271, GCN 17288). Although the filters are slightly different, this may suggest optical fading of this source, which would strengthen its association with GRB 150101B. We further note that this position clearly lies on the stellar field of the galaxy 2MASX J12320498-1056010. Such luminous, non-nuclear X-ray sources are extremely rare, and while a background AGN is possible, the small impact parameter makes this unlikely within the limited BAT error circle. The luminosity is much higher than for most short-GRB afterglows at this epoch, and there is apparently little evidence for X-ray variability (although this is complicated by the presence of the nearby AGN which is a factor ~4 brighter, Troja et al. GCN 17289). Hence, while we can not yet make firm claims about the relationship of the Magellan and Chandra source to GRB 150101B/ Swift J123205.1-105602, it remains a plausible candidate. "
GCN 17333 table
GRB_name GRB150101B
GCN_number 17333
Detection_method Optical
ra 188.0212°
decl -10.9342°
Circular_text TITLE: GCN CIRCULAR NUMBER: 17333 SUBJECT: GRB 150101B: Confirmation of a fading optical counterpart DATE: 15/01/21 02:13:12 GMT FROM: Wen-fai Fong at U of Arizona W. Fong (U. Arizona), E. Berger (Harvard), D. Fox (PSU) and B.J. Shappee (Carnegie) report: "We re-observed the field of the short/soft GRB 150101B (Cummings, GCN 17267) with the Gemini Multi-Object Spectrograph (GMOS) mounted on the Gemini-South 8-m telescope starting on 2015 Jan 12.326 UT, 10.7 days after the BAT trigger and 9.0 days after our initial Magellan observations (Fong et al., GCN 17271). We obtained a total of 1710-sec of r-band imaging in 0.58" seeing. To assess fading of the candidate optical afterglow (Fong et al., GCN 17271), we performed digital image subtraction using the ISIS package between the Gemini and Magellan observations. We find a residual point source with a refined position of RA(J2000) = 12:32:05.08 Dec(J2000) = -10:56:03.16 with an uncertainty of 0.5" in each coordinate. This indicates that the optical source has faded between 1.7 and 10.7 days post-burst. Thus far, this is the only evidence for a fading source within the BAT position. Fading is also supported by the lack of optical counterpart in other filters from late-time VLT observations (Levan et al., GCN 17321). We note that digital image subtraction between our two Magellan epochs at 1.7 days and 2.7 days post-burst revealed no residuals (Fong et al., GCN 17285), suggesting that the source had an initial period of shallow decay. The optical source is ~3.1" offset from the center of the galaxy 2MASX J12320498-1056010. Given the separation and optical brightness (Cummings et al., GCN 17268), the galaxy has a low probability of chance coincidence of ~2e-3. At the redshift of the galaxy, z=0.134 (Levan et al., GCN 17281), the projected physical offset is ~7.4 kpc. In addition, the location of the optical source is consistent with the position of the faint Chandra source (SRCX #2 in Troja et al., GCN 17289). We conclude that the fading of the optical source, spatial coincidence with an X-ray counterpart, and proximity to a galaxy with low probability of chance coincidence confirms the source as the optical afterglow, and 2MASX J12320498-1056010 as the host galaxy of GRB 150101B. At z=0.134, this is the among the lowest confirmed redshifts for a short GRB to date."
GCN 17431 table
GRB_name GRB150101B
GCN_number 17431
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 17431 SUBJECT: GRB 150101B/ Swift J123205.1-105602: Second epoch Chandra observations DATE: 15/02/10 18:37:00 GMT FROM: Andrew Levan at U.of Leicester A.J. Levan (U. Warwick), J. Hjorth (DARK/NBI), N.R. Tanvir (U. Leicester), A.J. van der Horst (GWU) report on behalf of a larger collaboration: "We obtained a second epoch of observations of the very short GRB 150101B/ Swift J123205.1-105602 (Cummings et al. GCN 17267) with Chandra. Observations began on 10 Feb 2015, 39 days after the burst, and 32 days after the first epoch of observations (Troja et al. GCN 17289). As in the first epoch of observations a total of ~15 ks of observations were obtained with the target placed on the ACIS-S3 chip. In these observations we clearly identify the two sources identified in previous observations. In a 1.5" aperture to avoid contamination of the sources with light from each other, we finds count rates for source SRCX1 and SRCX2 as identified by Troja et al. (GCN 17289) to be SRCX1=(35.8 +/- 1.6)e-3 and SRCX2=(1.5 +/- 0.3)e-3 respectively. This compares to SRCX1= (38.3 +/- 1.6)e-3 cps and SRCX2=(9.4 +/- 0.9)e-3 cps in the first epoch. This implies that the AGN has remained constant, and that the second source, coincident with the optical afterglow (Fong et al. GCN 17333, Levan et al. 17321) has faded by a factor of ~6. The X-ray variability observed from source SRCX2 confirms it as the afterglow of GRB 150101B/Swift J123205.1-105602. The corresponding decay index is approximately t^-1.1, this is relatively slow for a short GRB afterglow so late after burst, and at z=0.134 (Levan et al. GCN 17281) places it in a region of parameter space much more luminous than most short bursts of comparable prompt fluence at similar times. We thank Belinda Wilkes, Scott Wolk at the team at the Chandra X-ray Observatory for their help with these observations."
GCN 22889 table
GRB_name GRB150101B
GCN_number 22889
Detection_method INTEGRAL
Circular_text TITLE: GCN CIRCULAR NUMBER: 22889 SUBJECT: GRB150101B: INTEGRAL prompt gamma-ray signal from a possible GRB170817A-analogue DATE: 18/07/04 10:24:47 GMT FROM: Carlo Ferrigno at IAAT/ISDC J. Rodi, A. Bazzano, P. Ubertini (IAPS-Roma) E. Bozzo, C. Ferrigno, V. Savchenko (ISDC, University of Geneva, CH) E. Kuulkers (ESTEC/ESA, The Netherlands) D. Gotz (DRF/Irfu/DAp Saclay/CEA) L. Hanlon, A. Martin-Carrillo (UCD, Ireland) J. M. Mas-Hesse (CSIC-INTA, Spain) S. Mereghetti (INAF IASF-Milano, Italy) L. Natalucci (IAPS-Roma) A. Lutovinov, R. Sunyaev (IKI, Russia) report on behalf of the INTEGRAL Gravitational Wave Team We have analyzed INTEGRAL archival data of the SPI-ACS and IBIS/PICsIT in coincidence with GRB150101B (GCN 17267, GCN 17276). Troja et al. (2018, arXiv:1806.10624) suggest that GRB150101B is a kilonova event comparable to GW170817/GRB170817A, but at cosmological distance and without the observations of a gravitational-wave trigger. The INTEGRAL orientation was 24.9 degrees from the GRB location and implies a somewhat suppressed response for SPI-ACS, but an improved response for IBIS, especially IBIS/PICsIT (Savchenko et al. 2017, A&A 603, A46). We confirm the independent detection by SPI-ACS and IBIS/PICsIT of a short duration (~0.012 sec) event, consistent with that reported in Troja et al. The signal in SPI-ACS (75 keV-10 MeV) and in IBIS/PICsIT (200 keV-1.2 MeV) has a S/N of 5.1, and 4.2, respectively. From the SPI-ACS observation, we estimate a 75 keV-2 MeV fluence of GRB150101B in the time interval T_0-0.05s - T_0+0.1s of (1.3 ± 0.3)e-7 erg/cm2, assuming a simple power-law spectrum with a slope of 1.2 (as measured by Swift/BAT and Fermi/GBM). Analysis is on-going to constrain any possible soft gamma-ray afterglow with contemporaneous INTEGRAL observations. A plot of the light curve can be found at https://zenodo.org/record/1304812#.WzyLLa14VGw