GRB 160223B

D.Gotz (CEA, Saclay), S.Mereghetti (IASF-Milano), C.Ferrigno, E.Bozzo, S. Fotopoulou(ISDC, Versoix), and J.Borkowski (CAMK, Torun) on behalf of the IBAS Localization Team report:
a gamma ray burst lasting about 30 s has been detected by IBAS in the IBIS/ISGRI data at 09:58:58 UT of February 23, 2016.

The refined coordinates (J2000) are:

R.A.=   94.9937 deg
DEC.=   +33.4075 deg

with an uncertainty of 2.2 arcmin (90% c.l.).

The burst had a peak flux of 1.2 counts/cm2/s (20-200 keV, 1-s integration 
time) and a fluence in the same energy range of about 1.6e-6 erg/cmsq.

A plot of the light curve will be posted at 
http://ibas.iasf-milano.inaf.it/IBAS_Results.html

P. A. Evans (U. Leicester) reports on behalf of the Swift team:

Swift has initiated a ToO observation of the INTEGRAL GRB 160223B. 
Automated analysis of the XRT data will be presented online at
http://www.swift.ac.uk/ToO_GRBs/00020601

Any uncatalogued X-ray sources detected in this analysis will be
reported on this website and via GCN COUNTERPART notices. These are
not necessarily related to the INTEGRAL event. 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; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).

This circular is an official product of the Swift-XRT team.

A. von Kienlin, H.-F. Yu, and K. Toelge (all MPE) 
report on behalf of the Fermi GBM Team:

"At 09:59:01.51 UT on 23 February 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 160223B (trigger 477914345 / 160223416),
which was also detected by INTEGRAL (Götz et al. 2016, GCN 19059
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 )
The GBM on-ground location is consistent with the INTEGRAL position.

The angle from the Fermi LAT boresight at the GBM trigger time is 49 degrees.

The GBM light curve shows a structured pulse
with a duration (T90) of about 17 s (50-300 keV).
The time-averaged spectrum from T0-2.560 s to T0+16.896 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -0.90 (+0.08/-0.07)  and
the cutoff energy, parameterized as Epeak, is 560 (+110 /-80) keV

The event fluence (10-1000 keV) in this time interval is
(5.9 +/- 0.3)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+0.256 s in the 10-1000 keV band
is 3.1 +/- 0.2 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog."

S. Dichiara, C. Guidorzi (U. Ferrara), S. Kobayashi (LJMU),
A. Gomboc (U. Nova Gorica), C.G. Mundell (U. Bath), on behalf
of a larger collaboration report:

The 2-m LCOGT Faulkes Telescope North began observing
INTEGRAL and Fermi GRB 160223B (Gotz et al. GCN 19059
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 ,
von Kienlin et al., GCN 19061
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 ) on Feb 23 at 10:06:58 UT
(7.8 minutes after the burst trigger) with r filter.
We do not detect any optical afterglow candidate within the
INTEGRAL error circle (Gotz et al. GCN 19059
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 ) down to the
following magnitudes:

Mid Time      Exposure       Filter       Magnitude
(min)           (s)
-------------------------------------------------------
12.27          5x120            r'          > 20.5
-------------------------------------------------------

Values have been calibrated against nearby USNOB-1 stars
(R2)

T.G.R. Roegiers (PSU), L.M. McCauley (PSU), J.A. Kennea (PSU), S.L.
Gibson (U. Leicester), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), A. D'Ai
(INAF-IASFPA) and P.A. Evans (U. Leicester) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the INTEGRAL-detected
burst GRB 160223B (Gotz et al. GCN Circ. 19059
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 ), collecting 2.3 ks of
Photon Counting (PC) mode data between T0+10.6 ks and T0+16.4 ks. 

No X-ray sources have been detected inside or close to the INTEGRAL
error region. The 3-sigma upper limit in the field ranges from ~0.004
to ~0.005 ct s^-1, corresponding to a 0.3-10 keV observed flux of
1.8e-13 to 1.9e-13 erg cm^-2 s^-1 (assuming a typical GRB spectrum).

The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
http://www.swift.ac.uk/ToO_GRBs/00020601.

This circular is an official product of the Swift-XRT team.

E. Mazaeva (IKI), S. Schmalz (ISON), A. Volnova (IKI),  N. Tungalag 
(Research Center of Astronomy and Geophysics MAS),   I. Molotov (KIAM),
 A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration:

We observed the field of INTEGRAL and Fermi GRB 160223B GRB 160223B (Gotz et 
al. GCN 19059
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 ; von Kienlin et al., GCN 19061
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 ) with ORI-40 telescope of 
Khureltogot observatory starting on Feb., 23 (UT) 12:34:31.  Within 2.2 
arcmin error circle of the GRB 160223B localization  (Gotz   et al., GCN 
19059
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 ) we marginally detect two possible sources not presented in USNO-B1.0 
catalog. Coordinates of the sources are

Source (1): (J2000) 6:20:05.53 +33:24:58.7
Source (2): (J2000) 6:20:03.89 +33:23:14.2

with uncertainties of 1 arcsec in both coordinates.
At this time we cannot confirm the sources are real  or variable due to low 
S/N and absence of a full dataset.

Preliminary photometry of the sources is following


Date UT start       t-T0   Filter Exp.   OT   Err   UL(3sigma) Source#
                     (mid, days)   (s)

2016-02-23 12:34:31  0.14969 none  7200   18.7 0.35  18.9  (1)
2016-02-23 12:34:31  0.14969 none  7200   18.7 0.30  18.9  (2)

Photometry is based on nearby USNO-B1.0  stars, R2 magnitudes:
USNO-B1_id        R2
1234-0146334    14.41
1234-0146221    14.55
1233-0156534    14.77
1234-0146470    13.48
1234-0146172    13.37

A.Gabovich, V.Yurkov, Yu.Sergienko, D.Varda
Blagoveschensk Educational State University, Blagoveschensk

N.Tyurina, V. Lipunov, E. Gorbovskoy,  V.Kornilov, 
P.Balanutsa, A.Kuznetsov, D.Kuvshinov
Lomonosov Moscow State University,
Sternberg Astronomical Institute, Moscow State University

D.Buckley, S. Potter, M.Kotze
South African Astronomical Observatory

K.Ivanov, N.M.Budnev, O.Gres, V.A.Poleshchuk
Irkutsk State University

A. Tlatov, V.Senik, A.V. Parhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

R. Rebolo, M. Serra-Ricart, N. Lodieu, G. Israelian
The Instituto de Astrofisica de Canarias

MASTER-Amur  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Blagoveschensk was pointed to the  GRB160223B  32 sec after 
trigger time at 2016-02-23 09:59:30 UT. On 
our first  set  (10 sec,  unfiltered) we  not found optical transients 
within  INTEGRAL error-box (ra=06 19 54 dec=+33 24 21 r=2'.2 ) brighter 
then  15.8.

The message may be cited.

S. Ozawa (Wasoeda U), A. Yoshida, T. Sakamoto, I. Takahashi, Y. Kawakubo, 
K. Senuma, M. Moriyama, Y. Yamada (AGU), K. Yamaoka (Nagoya U), S. Nakahira (JAXA), 
Y. Asaoka, S. Torii (Waseda U), Y. Shimizu, T. Tamura (Kanagawa U), W. Ishizaki (ICRR), 
M. L. Cherry (LSU), S. Ricciarini (U of Florence) P. S. Marrocchesi (U of Siena) 
and the CALET collaboration:

The long-duration GRB160223B (Gotz et al., GCN Circ. 19059
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 ; von Kienlin et al., GCN Circ. 19061
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 ) 
triggered the CALET Gamma-Ray Burst Monitor (CGBM) at 09:58:59.5 on 23 February 2016.  
The burst signal was detected by SGM instrument.  

The light curve of the SGM shows at least three peaks.  The emission starts at T0, 
peaks at T0+1 sec and ends at T0+25 sec.   The T90 duration measured by the SGM data 
is 11 +- 1 sec (40-1000 keV). 

The CGBM data used in this analysis are provided by the Waseda CALET Operation Center 
located at the Waseda University.