GRB 150323C
GCN Circular 17671
Subject
GRB 150323C: CrAO optical observations
Date
2015-04-04T11:23:31Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
V. Rumyantsev (CrAO), K. Antoniuk (CrAO), E. Mazaeva (IKI), A. Pozanenko
(IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the GRB 150323C (Amaral-Rogers et al., GCN 17621)
with AZT-11 telescope of CrAO observatory starting on Mar. 23 (UT) 20:09:58.
We obtained ages in R-filter of 180 s exposure under non-optimal weather
conditions and mean FWHM of about 4.7 arcsec. In the enhanced XRT position
(Osborne et al., GCN 17633) we do not detect any object. In particular we
do no detect optical afterglow (Xu et al. GCN 17625, Xin et al. GCN 17631;
Watson et al. GCN 17632). An upper limit is following
Date UT start, t-t0 Filter Exp. OT UL (3
sigma)
(mid, days) (s)
2015-03-23 20:09:58 0.14949 R 20*180 n/d 21.0
The photometry is based on nearby USNO-B1.0 stars.
GCN Circular 17670
Subject
GRB 150323C: additional optical observations in Mondy
Date
2015-04-04T11:16:29Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Volnova (IKI), E. Klunko (ISTP), I. Korobtsev (ISTP),
M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of larger GRB
follow-up collaboration:
We additionally observed the field of the GRB 150323C (Amaral-Rogers et
al., GCN 17621) with AZT-33IK telescope of Sayan observatory (Mondy) on
Mar., 27 and Mar. 30 under good weather conditions and mean FWHV of 1.8
arcsec. We obtained several images in R-filter of 120 s exposure. In both
epochs we detect a source in coordinates (J2000) 12 50 27.90 +50 11 29.0
(+/- 0.45" ) which is within afterglow coordinates (Xu et al., GCN 17625)
and within the enhanced Swift-XRT position (Osborne et al., GCN 17633). Our
object is apparently the same object suggested as a possible host galaxy
(Malesani et al., GCN 17655). Preliminary photometry of the source is
following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2015-03-27 18:22:30 4.11333 R 85*120 22.7 0.25
2015-03-30 14:09:29 7.02068 R 194*120 22.3 0.15
Photometry is based on SDSS DR9 stars:
SDSS9_id R(Lupton)
J125023.08+501048.2 16.84
J125032.04+501021.5 18.37
Also we note that our photometry reported early (Mazaeva et al., GCN 17639)
may by significantly be significantly influenced by the possible host
galaxy.
GCN Circular 17669
Subject
GRB 150323C: Khureltogot optical observations
Date
2015-04-04T11:07:51Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of
Astronomy and Geophysics MAS), A. Volnova (IKI), I.Molotov (KIAM), A.
Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:
We observed the field of the GRB 150323C (Amaral-Rogers et al., GCN 17621)
with ORI-40 telescope of Khureltogot observatory starting on Mar., 23 (UT)
17:20:51, i.e. ~15 minutes after burst trigger. We obtained 180 unfiltered
images of 60 s exposure. Within enhanced Swift-XRT error circle (Osborne et
al., GCN 17633) we detect optical afterglow (Xu et al. GCN 17625, Xin et
al. GCN 17631; Watson et al. GCN 17632). Preliminary photometry of the
afterglow in combined images is following
Date UT start t-T0 Filter Exp. OT OT_err
(mid, days) (s)
2015-01-23 17:20:51 0.01449 none 10*60 21.1 0.3
2015-01-23 17:31:40 0.02199 none 10*60 20.5 0.25
2015-01-23 17:42:28 0.02950 none 10*60 20.8 0.25
2015-01-23 17:53:17 0.03700 none 10*60 20.2 0.2
2015-01-23 18:04:04 0.04451 none 10*60 20.0 0.2
2015-01-23 18:14:54 0.06199 none 35*60 21.3 0.3
2015-01-23 18:54:26 0.09409 none 39*60 21.0 0.3
2015-01-23 19:57:04 0.13649 none 40*60 21.5 0.4
Photometry is based on SDSS DR9 stars:
SDSS9_id R(Lupton)
J125026.13+501147.9 16.16
J125023.08+501048.2 16.84
Our photometry confirms non-monotonic behaiviour of a lighr curve of the
afterglow mentioned by Xin et al. (GCN 17631).
The light curve of GRB 150323C afterglow can be found in
http://grb.rssi.ru/GRB150323C/GRB150323C_ORI40_lc.png
GCN Circular 17655
Subject
GRB 150323C: possible host galaxy detection
Date
2015-03-29T20:03:27Z (12 years ago)
From
Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst <malesani@dark-cosmology.dk>
Daniele Malesani (DARK/NBI), Dong Xu (DARK/NBI), Pall Jakobsson (Univ.
Iceland) and Jussi Harmanen (NOT and Univ. Turku) report on behalf of
a larger collaboration:
We observed the field of GRB 150323C (Amaral-Rogers et al., GCN 17621;
Stanbro, GCN 17627) using the Nordic Optical Telescope (NOT) located in
La Palma. The mean time of the observation was March 28.21 UT, that is
4.49 days after the GRB. A 20 min exposure was collected using the SDSS
r filter.
Close to the position of the optical afterglow (Xu et al., GCN 17625;
Watson et al., GCN 17632), we detect an object with r = 23.6 +- 0.2 AB
(calibrated against nearby SDSS stars). This source is also marginally
detected in the archival SDSS images with a comparable (though
uncertain) brightness, and therefore an underlying galaxy must be
contributing a significant fraction of the light.
We note a small, but significant offset between the afterglow and the
galaxy positions. By registering astrometrically the afterglow image by
Xu et al. (GCN 17625) with the new NOT data, we find an offset of
approximately 0.65". Such an offset is not unprecedented, so that the
SDSS/NOT object is still a viable host galaxy candidate for GRB 150323C.
[GCN OPS NOTE(30mar15): Per author's request, JH's affiliation was changed.]
GCN Circular 17648
Subject
GRB 150323C: Nishi-Harima NIR Observations
Date
2015-03-26T19:33:31Z (12 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
S. Honda. J. Takahashi, Y. Takagi, K. Morihana, Y. Itoh
(Univ. of Hyogo), and Y. Saito (Tokyo Tech)
report on behalf of Nayuta team and OISTER collaboration:
We observed the field of GRB 150323C (Amaral-Rogers et al., GCN 17621)
with Nishiharima Infrared Camera (NIC) attached to the Nayuta 2-m
telescope at the Nishi-Harima Astronomical Observatory.
The observations were started at 17:30 UT on 2015-03-23.
We detected the near-infrared afterglow in J, H and Ks bands.
Photometric results of our observations are shown below.
We used 2MASS 12502614+5011480, 12502605+5011289, 12503202+5010217,
and 12503649+5012012 as reference stars for photometry.
# MID-UT Tmid-T0 T-EXP J_mag H_mag Ks_mag
--------------------------------------------------------------------------------
17:33:16 28 1200 18.22 +/- 0.10 17.25 +/- 0.10 16.44 +/- 0.13
17:59:27 54 1200 18.68 +/- 0.11 17.59 +/- 0.11 16.94 +/- 0.14
18:25:32 80 1200 19.40 +/- 0.20 17.77 +/- 0.13 17.23 +/- 0.14
---------------------------------------------------------------------------------
Tmid-T0: Elapsed time after the burst (minutes)
T-EXP: Total Exposure time (seconds)
GCN Circular 17646
Subject
GRB 150323C: MITSuME Akeno Optical observation
Date
2015-03-26T14:10:07Z (12 years ago)
From
Taketoshi Yoshii at Tokyo Tech <yoshii.t.ac@m.titech.ac.jp>
T.Fujiwara, Y. Saito, T. Yoshii, Y. Tachibana, H. Ohuchi,
Y. Yano, S.Kurita, Y. Ono, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:
We observed the field of GRB 150323C (Amaral-Rogers et al. GCN Circular #17621) with the
optical three color (g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm
telescope of Akeno Observatory, Yamanashi, Japan.
The observation started at 2015-03-23 17:06:46 UT (85 sec after the burst).
We detected the previously reported optical afterglow (Xu et al. GCN Circular #17625) in the Rc band.
The measured magnitudes are listed below.
T0+[sec] MID-UT T-EXP[sec] g' Rc Ic
----------------------------------------------------------------------
85 17:09:24 270 > 19.9 > 19.6 > 18.5
1069 17:34:06 1200 > 20.9 20.3 $B!^(B 0.5 > 19.5
6681 19:18:53 2400 > 20.4 > 20.4 > 19.4
----------------------------------------------------------------------
T0+ : Elapsed time after the burst
T-EXP: Total Exposure time
We used GSC2.3 catalog for flux calibration.
GCN Circular 17644
Subject
Subject: GRB 150323C; Konkoly optical observations
Date
2015-03-25T21:02:06Z (12 years ago)
From
Janos Kelemen at Konkoly Obs/Hungary <kelemen@konkoly.hu>
J. Kelemen (kelemen at konkoly.hu) on behalf of the GRB OT observing program
at the Konkoly Observatory.
Starting on the night 23/03/2015 we observed the field GRB 150323C
(A. Amaral-Rogers et al. GCN 17621 ). On the position reported by D. Xu et al.
(GCN 17625) according our coadded R images we confirmed the presence of a
marginal optical source in R band.
Position from D. Xu our work
---------------------------------------------------------------
RA(J2000) = 12:50:27.92 RA: 12:50:28.02
Dec(J2000) = +50:11:28.75 DEC: 50:11:28.3
Photometric results: (Based on nearby USNO-B1.0 stars)
time from GRB. exp filter Mag.
------------------------------------------------
10653 s. 1800 s R 21.7 +/-0.18
------------------------------------------------
GCN Circular 17639
Subject
GRB 150323C: Mondy optical observations
Date
2015-03-25T13:29:01Z (12 years ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
E. Mazaeva (IKI), A. Volnova (IKI), E. Klunko (ISTP), I. Korobtsev
(ISTP), M. Eselevich (ISTP), A. Pozanenko (IKI) report on behalf of
larger GRB follow-up collaboration:
We observed the field of the GRB 150323C (Amaral-Rogers et al., GCN
17621) with AZT-33IK telescope of Sayan observatory (Mondy) starting on
Mar., 23 (UT) 11:42:02. We obtained several images in R-filter of 120 s
exposure. Within enhanced Swift-XRT error circle (Osborne et al., GCN
17633) we clearly detect optical afterglow (Xu et al. GCN 17625, Xin
et al. GCN 17631; Watson et al. GCN 17632) in a combined image.
Preliminary photometry of the afterglow is following
Date UT start t-T0 Filter Exp. OT Err.
(mid, days) (s)
2015-03-24 15:14:09 0.95405 R 44*120 22.4 0.3
Photometry is based on SDSS DR9 stars:
SDSS9_id R(Lupton)
J125023.08+501048.2 16.84
J125032.04+501021.5 18.37
J125016.28+501035.8 18.22
GCN Circular 17637
Subject
GRB 150323C, Swift-BAT refined analysis
Date
2015-03-24T20:28:56Z (12 years ago)
From
Amy Lien at GSFC <amy.y.lien@nasa.gov>
D. M. Palmer (LANL), Amaral-Rogers (U Leicester), S. D. Barthelmy (GSFC),
W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), 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-274 to T+800 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 150323C (trigger #636005)
(Amaral-Rogers, et al., GCN Circ. 17621). The BAT ground-calculated position is
RA, Dec = 192.625, 50.165 deg which is
RA(J2000) = 12h 50m 30.1s
Dec(J2000) = +50d 09' 55.3"
with an uncertainty of 2.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.
The mask-weighted light curve shows several weak overlapping pulses. The main
burst structure starts at ~ T-20 s and ends at ~T+20 s, followed by another weaker
pulse lasting till ~ T+160 s. T90 (15-350 keV) is 159.4 +- 54.0 sec (estimated error
including systematics).
The time-averaged spectrum from T-22.9 to T+166.3 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
2.09 +- 0.32. The fluence in the 15-150 keV band is 1.3 +- 0.3 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+5.98 sec in the 15-150 keV band
is 1.1 +- 0.3 ph/cm2/sec. All the quoted errors are at the 90% confidence
level.
The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/636005/BA/
GCN Circular 17636
Subject
GRB 150323C: RATIR Optical Afterglow Observations - Errata
Date
2015-03-24T17:19:02Z (12 years ago)
From
Alan M. Watson at Instituto de Astronomia UNAM <alan@astro.unam.mx>
Alan M. Watson (UNAM), Owen Littlejohns (ASU), Nat Butler (ASU),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC),
Jos� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes�s Gonz�lez
(UNAM), Carlos Rom�n-Z��iga (UNAM), Neil Gehrels (GSFC), and
Harvey Moseley (GSFC) report:
In Watson et al. (GCN Circular 17632), we compared our RATIR
observations of GRB
150323C to earlier observations to derive an approximate temporal
power-law index
of 0.5. We unfortunately gave an incorrect reference to the earlier
observations; the
correct reference is Xu et al. (GCN Circular 17625).
We apologise for any confusion.
GCN Circular 17635
Subject
GRB 150323C: Swift/UVOT Upper Limits
Date
2015-03-24T12:55:50Z (12 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and A. Amaral-Rogers (U Leicester)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 150323C
179 s after the BAT trigger (Amaral-Rogers et al., GCN Circ. 17621).
No optical afterglow consistent with the optical position
(Xu et al. GCN Circ. 17625) 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) exposure and subsequent exposures are:
Filter T_start(s) T_stop(s) Exp(s) Mag
white_FC 179 328 147 >21.5
u_FC 337 587 246 >20.7
white 179 11759 1513 >22.4
v 669 12698 555 >21.0
b 594 7661 444 >21.1
u 337 7541 717 >21.0
w1 718 7337 432 >21.2
m2 5494 7131 393 >20.6
w2 5084 12665 1279 >22.1
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.01 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 17633
Subject
GRB 150323C: Enhanced Swift-XRT position
Date
2015-03-24T09:02:46Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester)
report on behalf of the Swift-XRT team.
Using 5836 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 150323C, 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 = 192.61686, +50.19121 which is equivalent
to:
RA (J2000): 12h 50m 28.05s
Dec (J2000): +50d 11' 28.4"
with an uncertainty of 1.6 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 Circular 17632
Subject
GRB 150323C: RATIR Optical Afterglow Observations
Date
2015-03-24T06:49:44Z (12 years ago)
From
Owen Littlejohns at Az State U <olittlej@asu.edu>
Alan M. Watson (UNAM), Owen Littlejohns (ASU), Nat Butler (ASU),
Alexander Kutyrev (GSFC), William H. Lee (UNAM), Michael G.
Richer (UNAM), Chris Klein (UCB), Ori Fox (UCB), J. Xavier
Prochaska (UCSC), Josh Bloom (UCB), Antonino Cucchiara
(ORAU/GSFC), Eleonora Troja (GSFC), Enrico Ramirez-Ruiz (UCSC),
Jos� A. de Diego (UNAM), Leonid Georgiev (UNAM), Jes�s Gonz�lez
(UNAM), Carlos Rom�n-Z��iga (UNAM), Neil Gehrels (GSFC), and
Harvey Moseley (GSFC) report:
We observed the field of GRB 150323C (Amaral-Rogers, et al., GCN
17621) with the Reionization and Transients Infrared Camera
(RATIR; www.ratir.org) on the 1.5m Harold Johnson Telescope at
the Observatorio Astron�mico Nacional on Sierra San Pedro M�rtir
from 2015/03 24.14 to 2015/03 24.27 UTC (10.20 to 13.42 hours
after the BAT trigger), obtaining a total of 2.49 hours exposure
in the r, i and z bands.
For a source within the Swift-XRT error circle (D'Elia, et al.,
GCN 17630), in comparison with the SDSS DR9, we obtain the
following detections and upper limit (3-sigma):
r 23.00 +/- 0.15
i 22.63 +/- 0.11
z > 20.61
These magnitudes are in the AB system and are not corrected for
Galactic extinction in the direction of the GRB. In comparison to
an earlier epoch of observations (Xin, et al., GCN 17631) we find
this magnitude to be consistent with a power-law decay with an
approximate temporal decay index alpha = 0.5.
We thank the staff of the Observatorio Astron�mico Nacional in
San Pedro M�rtir.
GCN Circular 17631
Subject
GRB 150323C : Xinglong TNT optical observation
Date
2015-03-24T05:34:21Z (12 years ago)
From
L.P. Xin at NAOC <xlp@bao.ac.cn>
L. P. Xin, X. F. Wang, 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 150323C (Amaral-Rogers et al., GCN 17621)
with Xinglong 0.8-m TNT telescope at 2015-03-23, 17:07:27(UT),
about 126 sec after the Swift trigger time.
The new source within XRT circle (Amaral-Rogers et al., GCN 17621 )
reported by Xu et al., ( GCN 17625 ) was clearly detected in our coadded images.
Preliminary analysis shows that the brightness of this optical transient
in R band is rising from 21.6 to 20.2 and then decaying,
indicating that this source is the optical afterglow of the burst.
All the magnitudes are calibrated by a nearby USNO B1.0 object
( RA: 16:50:26 DEC: 50:11:48, R2=16.47mag ).
The message may be cited.
GCN Circular 17630
Subject
GRB 150323C: Swift-XRT refined Analysis
Date
2015-03-24T05:15:04Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
V. D'Elia (ASDC), M. de Pasquale (INAF-IASFPA), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), K.L. Page (U.
Leicester), C. Pagani (U. Leicester), A.P. Beardmore (U. Leicester), A.
Maselli (INAF-IASFPA) and A. Amaral-Rogers report on behalf of the
Swift-XRT team:
We have analysed 6.1 ks of XRT data for GRB 150323C (Amaral-Rogers et
al. GCN Circ. 17621), from 160 s to 12.6 ks after the BAT trigger. The
data comprise 312 s in Windowed Timing (WT) mode (the first 9 s were
taken while Swift was slewing) with the remainder in Photon Counting
(PC) mode. The best available XRT position (using the promptly
downlinked event data, the XRT-UVOT alignment and matching UVOT field
sources to the USNO-B1 catalogue) is RA, Dec = 192.6169, 50.1918 which
is equivalent to:
RA (J2000): 12 50 28.05
Dec(J2000): +50 11 30.4
with an uncertainty of 2.1 arcsec (radius, 90% confidence).
The late-time light curve (from T0+5.1 ks) can be modelled with a
power-law decay with a decay index of alpha=1.0 (+/-0.5).
A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.34 (+/-0.05). The
best-fitting absorption column is 1.55 (+0.13, -0.12) x 10^21 cm^-2,
in excess of the Galactic value of 1.2 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.52 (+0.25, -0.23)
and a best-fitting absorption column of 6.5 (+4.5, -3.9) x 10^20 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum is 2.7 x 10^-11 (3.5 x 10^-11) erg cm^-2
count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 6.5 (+4.5, -3.9) x 10^20 cm^-2
Galactic foreground: 1.2 x 10^20 cm^-2
Excess significance: 2.2 sigma
Photon index: 2.52 (+0.25, -0.23)
If the light curve continues to decay with a power-law decay index of
1.0, the count rate at T+24 hours will be 3.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 9.8 x
10^-14 (1.3 x 10^-13) erg cm^-2 s^-1.
The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00636005.
This circular is an official product of the Swift-XRT team.
GCN Circular 17629
Subject
GRB 150323C: Xingming upper limit
Date
2015-03-24T04:09:25Z (12 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), X. Gao (Urumqi No.1 Senior High School, Xinjiang),
and Z.-J. Xu (Nanjing Putian Telecommunications Co. Ltd., Jiangsu)
report:
We observed the field of GRB 150323C (Amaral-Rogers et al., GCN 17621)
using the 0.35m robotic Xingming telescope located at Nanshan,
Xinjiang, China. Observations started at 17:08:06 UT on 2015-03-23,
i.e., 165 s after the burst, and a series of 40s, 60s, and 90s
unfiltered exposures were obtained.
No optical source is detected at the enhanced Swift-XRT position
(Evans, GCN 17624), down to a limiting magnitude of ~19.2 mag since
the starting of our observations.
GCN Circular 17627
Subject
GRB150323C: Fermi GBM detection
Date
2015-03-24T00:25:37Z (12 years ago)
From
Matthew Stanbro at UAH/Fermi <mcs0001@uah.edu>
Matthew Stanbro (UAH) reports on behalf of the Fermi GBM Team:
"At 17:05:09.64 UT on 23 March 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150323C (trigger 448823112 / 150323712)
which was also detected by the Swift/BAT (Amaral-Rogers et al. 2015, GCN 17621)
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is 58 degrees.
The GBM light curve consists of several episodes
with a duration (T90) of about 43 s (50-300 keV).
The time-averaged spectrum from T0-10.24 s to T0+30.72 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.15 +/- 0.16 and
the cutoff energy, parameterized as Epeak, is 107 +/- 18 keV.
The event fluence (10-1000 keV) in this time interval is
(2.50 +/- 0.19)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-1.22 s in the 8-1000 keV band
is 1.64 +/- 0.20 ph/s/cm^2.
The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."
GCN Circular 17625
Subject
GRB 150323C: Nanshan optical afterglow detection
Date
2015-03-23T18:10:39Z (12 years ago)
From
Dong Xu at DARK/NBI <dong.dark@gmail.com>
D. Xu (DARK/NBI), H.-B. Niu, J.-Z. Liu, G.-X. Pu, A. Esamdin, L. Ma
(XAO) report:
We observed the field of GRB 150323C (Amaral-Rogers et al., GCN 17621)
using the 1m telescope at Nanshan, Xinjiang, China. Observations were
carried out in R-band, starting at 17:19:50 UT on 2015-03-23, i.e.,
869 s after the burst.
A source, not present in SDSS and DSS, is well detected in individual
images at coordinates
RA(J2000) = 12:50:27.92
Dec(J2000) = +50:11:28.75
with an uncertainty of ~ 1 arcsec, being consistent with the enhanced
Swift-XRT position (Evans, GCN 17624). We thus think it's the optical
afterglow of the burst, and it has m(R) = 21.3 +/- 0.2 at a median
time of 1344s post-burst, calibrated with the SDSS field.
GCN Circular 17624
Subject
GRB 150323C: Prompt enhanced Swift-XRT position
Date
2015-03-23T17:48:13Z (12 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 150323C, we find an
enhanced XRT position of the afterglow: RA, Dec: 192.6169, 50.1918
which is equivalent to:
RA (J2000) = 12 50 28.05
Dec (J2000) = +50 11 30.4
with an uncertainty of 2.1 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/636005.
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 Circular 17622
Subject
GRB 150323C: MASTER-net optical observation
Date
2015-03-23T17:22:58Z (12 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University
E. Gorbovskoy, V. Lipunov, M.Pruzhinskaya, V.Kornilov, D.Kuvshinov,
N.Tyurina, N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov, V.V.Chazov,
D.Denisenko, A.Sankovich
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University
V.Krushinsky, I.Zalozhnih, A. Popov
Ural Federal University, Yekaterinburg, Kourovka
V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk
A. Tlatov, A.V. Parhomenko, D. Dormidontov, V.Sennik
Kislovodsk Solar Station of the Pulkovo Observatory
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)
D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Tunka was pointed to the GRB150323C 42 sec after notice time
and 88 sec after trigger time at 2015-03-23 17:09:39 UT in two
polarizations. On our first (20s exposure) set we haven`t found optical
transient within SWIFT error-box (Amaral-Rogers et al. GCN17621).
The 5-sigma upper limit has been about 17.6 mag
MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Ural was pointed to the GRB150323C 35 after notice time and 79
sec after trigger time at 2015-03-23 17:09:31 UT in two polarizations. On
our first (20s exposure) set we haven`t found optical transient within
SWIFT error-box (ra=12 50 28 dec=+50 11 25 r=0.001400).
The 5-sigma upper limit has been about 17.9 mag
The message may be cited.
GCN Circular 17621
Subject
GRB 150323C: Swift detection of a burst
Date
2015-03-23T17:15:23Z (12 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
A. Amaral-Rogers (U Leicester), W. H. Baumgartner (GSFC/UMBC),
H. A. Krimm (CRESST/GSFC/USRA), N. P. M. Kuin (UCL-MSSL),
K. L. Page (U Leicester), D. M. Palmer (LANL) and
B. Sbarufatti (INAF-OAB/PSU) report on behalf of the Swift Team:
At 17:05:21 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 150323C (trigger=636005). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 192.613, +50.198 which is
RA(J2000) = 12h 50m 27s
Dec(J2000) = +50d 11' 54"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a complex
structure with a duration of at least 40 sec. The peak count rate
was ~1000 counts/sec (15-350 keV), at ~5 sec after the trigger.
The XRT began observing the field at 17:08:11.3 UT, 169.8 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 192.6177, 50.1910 which is equivalent to:
RA(J2000) = +12h 50m 28.25s
Dec(J2000) = +50d 11' 27.6"
with an uncertainty of 5.2 arcseconds (radius, 90% containment). This
location is 27 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy.
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 178 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
0.01.
Burst Advocate for this burst is A. Amaral-Rogers (aar14 AT le.ac.uk).
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.)