Gamma-ray Burst 140402A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN Circular #16069
  E. Bissaldi (University & INFN Trieste), G. Vianello (Stanford U.) J. Chiang (KIPAC/SLAC) report on behalf of the Fermi-LAT team:
  At 00:10:07.00 on April 02, 2014, Fermi-LAT detected high-energy emission from GRB 140402AA, which was also detected by Fermi-GBM (trigger 418090209/140402A007).
  The best LAT on-ground location is found to be
  RA, Dec 207.47, 5.87 (J2000)
  with an error radius of 0.20 deg (90% containment, statistical error only). This position was 13 deg from the LAT boresight at the time of the trigger and is consistent with the last GBM ground location.
  The data from the Fermi-LAT show a significant increase in the event rate within 10 degrees of the GBM location after the GBM trigger that is spatially and temporally correlated with the GBM emission with high significance. More than 10 photons above 100 MeV are observed within 800 seconds. The highest-energy photon is a 3.5 GeV event which is observed 6.8 seconds after the GBM trigger. These numbers may increase as more data become available.
  A Swift ToO has been requested for this burst.
  The Fermi-LAT point of contact for this burst is Elisabetta Bissaldi (Elisabetta.Bissaldi@ts.infn.it).
  The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
• GCN Circular #16070
  Subject: GRB 140402AA: Fermi GBM detection
  Peter A. Jenke (UAH) and Hoi-Fung Yu (MPE) report on behalf of the Fermi GBM Team:
  "At 00:10:07.00 UT on 02 April 2014, the Fermi Gamma-Ray Burst Monitor triggered and located GRB 140402AA (trigger 418090209 / 140402A007). It was also detected by Fermi/LAT (Bissaldi et al. 2014, GCN 16069). The GBM on-ground location is consistent with the LAT position.
  The GBM light curve consists of a single pulse with a duration (T90) of about 0.3 s (50-300 keV). The time-averaged spectrum from T0-0.064 s to T0+0.064 s is well fit by a simple power law function with index -1.2 +/- 0.1.
  The event fluence (10-1000 keV) in this time interval is (4.0 +/- 0.4)E-07 erg/cm^2. The 64 ms peak photon flux measured starting from T0-0.064 s in the 10-1000 keV band is 4.6 +/- 0.7 ph/s/cm^2.
  The spectral analysis results presented above are preliminary; final results will be published in the GBM GRB Catalog."
• GCN Circular #16071
  J. R. Cummings, S. Barthelmy (GSFC), Hans Krimm (USRA/GSFC) on behalf of the Swift-BAT team
  At 00:10:06 Swift-BAT triggered on GRB 140402AA(trigger # 594308), also seen by FERMI-LAT (Bissaldi et al. GCN Circ #16069) and Fermi-GBM (Jenke & Yu, GCN Circ #16070) . There is a marginal BAT source (6 sigma), which is consistent with the Fermi-LAT position, at RA, Dec 207.651, +6.006, which is:

  RA (J2000) 13h 50m 36.2s
  Dec (J2000) 06d 00m 22s
  

  with an estimated 90% uncertainty radius of 4 arcmin. The partial coding was 73% (i.e. all of the Fermi-LAT error circle was in a fairly highly coded part of BAT's field of view). This burst appears to have a very hard spectrum. We may be able to improve the detection when we receive the photon event data.
  The unweighted lightcurve shows a single peak of about 0.32 seconds duration.
  A previous Swift TOO at the Fermi-LAT position did not cover this position. A new TOO has been requested.
• GCN Circular #16072
  L. P. Xin, M. Zhai, J. Y. Wei, Y. L. Qiu, J. S. Deng, J. Wang, X. H. Han and C. Wu on behalf of EAFON report:
  We began to observe GRB 140402AA (Bissaldi et al., GCN 16069; Peter et al, GCN 16070; Cummings et al., GCN 16071) under cloudy weather, with Xinglong 0.8-m TNT telescope at 16:04:37 (UT) , 15.95 hrs after the burst.
  No any new source in our 10*300 sec combined images down to the upper limit of 19.2 mag in R band, calibrated by nearby USNO B1.0 R2 mag.
• GCN Circular #16073
  J. R. Cummings on behalf of the BAT team
  Based on 10 seconds of photon event data, we present refined analysis of the BAT data on GRB 140402AA (Bissaldi et al. GCN Circ #16069, Cummings et al. GCN Circ #16071).
  The best BAT location is RA, Dec 207.592, +5.971, which is:

  RA(J2000) 13h 50m 22.2s
  Dec(J2000) 05d 58' 16"
  

  with an estimated 90% confidence radius of 2.8 arcmin. This is 4 arcmin from the previously reported BAT position based on the immediately transmitted data (4 arcmin estimated 90% error), and 9.5 arcmin from the Fermi-LAT position (12 arcmin estimated statistical 90% error).
  The mask-weighted lightcurve shows a single nearly square pulse. T90 was about 0.031 +/- 0.003 seconds (estimated 90% confidence).
  A powerlaw fit to the spectrum from 15 to 150 keV has a photon index of 0.89 +/- 0.44 (90% confidence). In 0.034 seconds the fluence was (3.8 +/- 1.2) x 10^-8 ergs/cm^2 (62% confidence).
• GCN Circular #16074
  V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University, Blagoveschensk
  K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk Irkutsk State University
  E. Gorbovskoy, V. Lipunov, M. Pruzhinskaya, D.Denisenko, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute
  A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory
  V.Krushinski, I.Zalozhnih, A. Popov Ural Federal University, Kourovka
  Hugo Levato and Carlos Saffe Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)
  Claudio Mallamaci, Carlos Lopez and Federico Podest Observatorio Astronomico Felix Aguilar (OAFA)
  MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Blagoveschensk was pointed to the GRB140402AA (Jenke et. al GCN 16070) ~ 13.6h (49103 sec) after trigger time at 2014-04-02 13:48:30 UT directly after sunset and the weather conditions became good. We haven`t found optical transient within Fermi-LAT (Bissaldi et. al. GCN 16069) and SWIFT-BAT (Cummings et. al GCN 16073) error-boxes on single and coadd images. The 5-sigma unfiltered upper limit has been about 18.2 mag on single (180 s) image and about 19.8 on coadd of 10 images with total exposure 1800 s.
  Also MASTER II robotic telescope located in Kislovodsk was twice pointed to this GRB by FERMI-GBM two alert coordinates 23 s and ~ 1h after trigger time. But the final Fermi-LAT and SWIFT-BAT position is out of our FOV due to big coordinates errors.
  The message may be cited.
• GCN Circular #16075
  C. Pagani (U. Leicester) reports on behalf of the Swift team:
  We report on Swift-XRT observations of the Fermi/GBM and Fermi/LAT-detected GRB 140402AA (Jenke & Yu, GCN Circ. 16070; Bissaldi, Vianello & Chiang, GCN Circ. 16069).
  The XRT observations consist of two pointings, the first centred on the reported Fermi/LAT GRB position (Bissaldi et al., GCN Circ. 16069), the second on the position derived from ground analysis of Swift-BAT data (Cummings, GCN Circ. 16071).
  The first XRT pointing consists of 4.5 ks of Photon Counting (PC) mode data, from 33.3 ks to 51.2 ks after the Fermi/LAT trigger, and is centred on the LAT position. No source is detected in the XRT data. The 3-sigma upper limit on the count rate is 3.6E-03 cts/s, which is 1.8E-13 erg cm^-2 s^-1 using a typical flux conversion of 5E-11 erg cm^-2 count^-1. These data only partially cover the BAT refined error circle (Cummings, GCN Circ. 16073).
  The second XRT pointing consists of 4.9 ks of PC mode data, from 56 ks to 107 ks after the Fermi/LAT trigger, and is centred on the BAT position. No source is detected in the XRT data. The 3-sigma upper limit on the count rate is 3.0E-03 cts/s, which is 1.5E-13 erg cm^-2 s^-1 using a typical flux conversion of 5E-11 erg cm^-2 count^-1.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #16077
  A. A. Breeveld (UCL-MSSL) and C. Pagani (U. Leicester) report on behalf of the Swift/UVOT team:
  The Swift/UVOT took exposures at both the pointings for GRB140402AA described in Pagani et al., GCN Circ. 16075. No optical afterglow consistent with the BAT position given by Cummings (GCN Circ. 16081) is detected in the UVOT exposures. Preliminary 3-sigma upper limits using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) are:

  Filter         T_start(s)   T_stop(s)      Exp(s)         Mag
  
  white            57023        57665         632          >21.5
  u                56375        61574         649          >20.5
  v                57672        58344         659          >19.8
  

  The magnitudes in the table are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.03 in the direction of the burst (Schlegel et al. 1998).
• GCN Circular #16078
  C. Pagani (U. Leicester) reports on behalf of the Swift team:
  We report on Swift-XRT observations of the Fermi/GBM and Fermi/LAT-detected GRB 140402AA (Jenke, GCN Circ. 16070, Bissaldi, GCN Circ. 16069).
  The XRT observations consist of two pointings, the first centered on the reported Fermi/LAT GRB position (Bissaldi, GCN Circ. 16069), the second on the position derived from ground analysis of Swift-BAT data (Cummings, GCN Circ. 16071).
  The first XRT pointing consists of 4.5 ks of Photon Counting (PC) mode data, from 33.3 ks to 51.2 ks after the Fermi/LAT trigger and are centered on the LAT position. No source is detected in the XRT data. The 3-sigma upper limit on the count rate is 3.6E-03 cts/s, which is 1.8E-13 erg cm^-2 s^-1 using a typical flux conversion of 5E-11 erg cm^-2 count^-1. These data only partially cover the BAT refined error circle (Cummings, GCN Circ. 16073).
  The second XRT pointing consists of 4.9 ks of PC mode data, from 56 ks to 107 ks after the Fermi/LAT trigger and are centered on the BAT position. No source is detected in the XRT data. The 3-sigma upper limit on the count rate is 3.0E-03 cts/s, which is 1.5E-13 erg cm^-2 s^-1 using a typical flux conversion of 5E-11 erg cm^-2 count^-1.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #16080
  W. Fong (Harvard), S. Ehlert (MIT), D. Osip (LCO/OCIW), B. Rackham (Arizona), M. McDonald (MIT), and E. Berger (Harvard) report:
  "We observed the location of the short-duration GRB 140402AA, detected by Fermi/LAT (Bissaldi et al., GCN 16069), Fermi/GBM (Jenke et al., GCN 16070) and Swift/BAT (Cummings et al., GCN 16071) with the Inamori Magellan Areal Camera and Spectrograph (IMACS) mounted on the Magellan/Baade 6.5-m telescope to cover the full refined BAT position (Cummings et al., GCN 16073). We obtained 3x300-sec r-band observations on 2014 Apr 03.22 UT (1.21 days post-burst) in 0.7" seeing at an airmass of 1.2. To check for the presence of a fading optical source, we re-observed the field (3x300-sec) on 2014 Apr 04.35 UT, 2.33 days post-burst and 1.12 days after the first set of observations. Digital image subtraction of the two epochs using the ISIS software package reveals no residuals in or around the BAT-refined position. Therefore, calibrated to SDSS DR9 sources in the same field, we place a 3-sigma limit of r>25.0 mag on the optical afterglow of GRB 140402AA at 1.21 days after the burst."