Gamma-ray Burst 150123A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• GCN/BACODINE POSITION NOTICE
  

  TITLE:           GCN/MAXI NOTICE
  NOTICE_DATE:     Fri 23 Jan 15 15:41:30 UT
  NOTICE_TYPE:     MAXI Unknown Source Position
  EVENT_ID_NUM:    45523329
  EVENT_RA:        111.56d {+07h 26m 14s} (J2000),
                   111.74d {+07h 26m 58s} (current),
                   110.96d {+07h 23m 51s} (1950)
  EVENT_DEC:        -9.69d {-09d 41' 27"} (J2000),
                    -9.72d {-09d 43' 18"} (current),
                    -9.59d {-09d 35' 23"} (1950)
  EVENT_ERROR:     1.0 [deg radius, stat+sys, 90% containment]
  EVENT_FLUX:      332.0 +- 0.0 [mCrab]
  EVENT_DATE:      17045 TJD;    23 DOY;   15/01/23
  EVENT_TIME:      54110.00 SOD {15:01:50.00} UT
  EVENT_TSCALE:    1s
  EVENT_EBAND:     Low, 2-4 keV
  SUN_POSTN:       305.61d {+20h 22m 26s}  -19.41d {-19d 24' 51"}
  SUN_DIST:        147.82 [deg] 
  MOON_POSTN:      346.65d {+23h 06m 36s}   -3.17d {-03d 10' 25"}
  MOON_DIST:       123.81 [deg] 
  MOON_ILLUM:      14 [%] 
  GAL_COORDS:      225.53,  3.21 [deg] galactic lon,lat of the burst (or transient)      
  ECL_COORDS:      115.08,-31.27 [deg] ecliptic lon,lat of the burst (or transient)      
  COMMENTS:        MAXI Unknown Source Position. GRB or unknown X-ray Transient.
  

• GCN Circular #17345
  K. Fukushima, H. Negoro (Nihon U.), M. Serino (RIKEN), S. Nakahira (JAXA), S. Ueno, H. Tomida, M. Kimura, M. Ishikawa, Y. E. Nakagawa (JAXA), T. Mihara, M. Sugizaki, M. Morii, J. Sugimoto, T. Takagi, A. Yoshikawa, M. Matsuoka (RIKEN), N. Kawai, T. Yoshii, Y. Tachibana (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, H. Ohtsuki (AGU), H. Tsunemi, D. Uchida (Osaka U.), M. Nakajima, T. Onodera, K. Suzuki, T. Namba, M. Fujita, F. Honda (Nihon U.), Y. Ueda, M. Shidatsu, T. Kawamuro, T. Hori (Kyoto U.), Y. Tsuboi, A. Kawagoe (Chuo U.), M. Yamauchi, Y. Morooka, D. Itoh (Miyazaki U.), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team:
  The MAXI/GSC nova alert system triggered a bright uncatalogued X-ray transient source at 15:01:50 UT . Assuming that the source flux was constant over the transit, we obtain the source position at
  (R.A., Dec) = (111.560 deg, -9.691 deg) = (07 26 14, -09 41 27) (J2000)
  with a statistical 90% C.L. elliptical error region with long and short radii of 0.14 deg and 0.13 deg respectively. The roll angle of long axis from the north direction is 110.0 deg counterclockwise. There is an additional systematic uncertainty of 0.1 deg (90% containment radius). The X-ray flux averaged over the scan was 332 +- 36 mCrab (4-10keV, 1 sigma error). There was no significant excess flux in the previous transit at UT 13:29 and in the next transit at 16:34 UT with an upper limit of 20 mCrab for each.
• GCN Circular #17346
  P. A. Evans (U. Leicester) reports on behalf of the Swift team:
  Swift has initiated a series of observations, tiled on the sky, of the MAXI GRB 150123A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00038
  Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the MAXI event is high: 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; and 2009, MNRAS, 397, 1177).
  This circular is an official product of the Swift-XRT team.
• GCN Circular #17348
  A. Melandri, P. D'Avanzo, M.G. Bernardini (INAF-OAB) & P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
  Swift-XRT has observed the error circle of the MAXI GRB 150123A in a series of observations tiled on the sky. The total exposure time is 3.7 ks spread over 4 fields; the maximum exposure within the sky observed was 1.6 ks. The observations started 9.8 ks after the MAXI trigger.
  Within these data there are 3 objects which are not catalogued in the X-rays.
  Source details:

  Source 1
  RA:  111.36420 = 07h 25m 27.41s (J2000)
  Dec:  -9.74880	 = -09d 44' 55.7" (J2000)
  Err: 5.9 (radius, 90% confidence)
  Exposure time: 814 s
  Online products:
  http://www.swift.ac.uk/xrt_products/TILED_GRB00038/index_1.php
  
  Source 2
  RA:  111.52056 = 07h 26m 4.93s (J2000)
  Dec:  -9.65269	 = -09d 39' 09.7" (J2000)
  Err: 4.4 (radius, 90% confidence)
  Exposure time: 1.3 ks
  Online products:
  http://www.swift.ac.uk/xrt_products/TILED_GRB00038/index_2.php
  
  Source 3
  RA:  111.40659 = 07h 25m 37.58s (J2000)
  Dec:  -9.55462	 = -09d 33' 16.6" (J2000)
  Err: 5.2 (radius, 90% confidence)
  Exposure time: 1.5 ks
  Online products:
  http://www.swift.ac.uk/xrt_products/TILED_GRB00038/index_3.php
  

  
  Source #1 is located 3" from an optical source present in the USNO-B1.0 catalogue with a magnitude of R=15.5. Source #2 is located 4" from an optical source present in the USNO-B1.0 catalogue with a magnitude of R=18.0. Source #3 matches the position of the known bright star TYC 5400-1552-1 (R=10.8).
  At the present time we cannot be sure which, if any, of these is the afterglow.
  This circular is an official product of the Swift-XRT team.
• GCN Circular #17349
  S. R. Oates (IAA-CSIC/UCL-MSSL) reports on behalf of the Swift/UVOT team:
  The Swift/UVOT began settled observations of the field of MAXI GRB 150123A 8.7ks after the trigger. No optical afterglow is detected within the MAXI error circle (Fukushima, GCN Circ. No. 17345). Using the UVOT photometric system (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) We obtain a typical 3 sigma upper limit of >20.6 in the u filter. This magnitude has not been corrected for the Galactic extinction due to the reddening of E(B-V) = 0.04 in the direction of the burst (Schlegel et al. 1998).
  In the error circles for XRT candidates #1, #2, and #3 we note the presence of objects that are catalogued in the USNO-B1, as discussed in Melandri et al. (GCN Circ. No. 17348). At the present time we cannot determine if any of these objects are fading.
• GCN Circular #17351
  S. Golenetskii, R.Aptekar, V. Pal'shin, D. Frederiks, P. Oleynik, M.Ulanov, D. Svinkin, and T. Cline on behalf of the Konus-Wind team report:
  The long GRB 150123A localized by MAXI/GSC (Fukushima et al., GCN 17345) was detected by Konus-Wind in the waiting mode.
  The burst light curve shows a single pulse started at ~T0(MAXI)-39 s with a duration of ~70 s.
  As observed by Konus-Wind, the burst had a fluence of 7.42(-0.80,+0.88)x10^-6 erg/cm2 and a 2.944-s peak flux, measured from ~T0(MAXI)-1 s, of (1.6 +/- 0.7)x10^-7 erg/cm2 (both in the 20 - 1200 keV energy range).
  Fitting the K-W 3-channel time-integrated spectrum (from T0(MAXI)-39 s to T0(MAXI)+31 s) by a simple power-law model yields a power law index of 1.82 +/- 0.1 (chi2=1.0/1 dof).
  All the quoted errors are estimated at the 1 sigma confidence level. All the presented results are preliminary.
  The K-W light curve of this burst is available at http://www.ioffe.rssi.ru/LEA/GRBs/GRB150123A/
• GCN Circular #17362
  E. Gorbovskoy, V. Lipunov, N.Tyurina, P.Balanutsa, D.Denisenko, A.Kuznetsov, V.Kornilov, D.Kuvshinov Lomonosov Moscow State University, Sternberg Astronomical Institute
  O.Gres, K.Ivanov, S.Yazev, N.M.Budnev, V.A.Poleshchuk Irkutsk State University
  V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov Blagoveschensk Educational State University
  A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik Kislovodsk Solar Station of the Pulkovo Observatory
  V.Krushinsky, I.Zalozhnih, A. Popov Ural Federal University, Kourovka
  D.Buckley, S. Potter, A.Kniazev, M.Kotze South African Astronomical Observatory
  H. Levato and C. Saffe Instituto de Ciencias Astronomicas de la Tierra y del Espacio (ICATE), San Juan, Argentina
  C. Mallamacci, C. Lopez and F. Podest Observatorio Astronomico Felix Aguilar (OAFA), San Juan National University, Argentina
  MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Tunka, Kislovodsk and SAAO made inspection inside MAXI GRB150123A (Fukushima et. al GCN 17345) error box which starting 3297 sec after trigger time at 2015-01-23 15:56:47 UT. We don't find creadible OT candidate in MAXI error box on single and coadd images with following upper limits.

  T_start  T-Tmid   Exp  Site Coadd Mlimit  Comment
  15:56:47   3297   180 Tunka    --   15.0  High clouds
  15:56:55   3305   180 Kilov    --   17.0  5 images only
  16:28:50   6562  1800 Tunka    10   19.0
  17:14:03   8974  1800 Tunka    10   19.0
  18:44:04  13186   180 SAAO     --   18.5  Starting after sunset.
  18:44:04  14398  1620 SAAO      9   20.6
  19:20:41  17075  1800 SAAO     10   20.6
  

  We also check all Swift-XRT transints (Melandri et. al. GCN 17348) on all out images. Source #1 is a galaxy with no avidance for brightening. Source #2 empty space with no OT and known stars at edge of error circle Source #3 position is blended by close bright stars.
  This message may be cited.