GRB 141109B

A. Melandri (INAF-OAB), S. D. Barthelmy (GSFC),
M. G. Bernardini (INAF-OAB), M. M. Chester (PSU),
P. D'Avanzo (INAF-OAB), C. B. Markwardt (NASA/GSFC) and
T. N. Ukwatta (LANL) report on behalf of the Swift Team:

At 07:47:39 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 141109B (trigger=618032).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 222.361, +73.125, which is 
   RA(J2000)  =  14h 49m 27s
   Dec(J2000) = +73d 07' 30"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve shows multiple peaks
with a duration of about 45 sec.  The peak count rate
was ~1000 counts/sec (15-350 keV), at ~6 sec after the trigger. 

The XRT began observing the field at 07:50:43.7 UT, 184.6 seconds after
the BAT trigger. Using promptly downlinked data we find a fading,
uncatalogued X-ray source with an enhanced position: RA, Dec 222.3033,
73.1306 which is equivalent to:
   RA(J2000)  = 14h 49m 12.79s
   Dec(J2000) = +73d 07' 50.3"
with an uncertainty of 2.1 arcseconds (radius, 90% containment). This
location is 63 arcseconds from the BAT onboard position, within the BAT
error circle. This position may be improved as more data are received;
the latest position is available at http://www.swift.ac.uk/sper. 

A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density in excess of the Galactic value (2.46 x
10^20 cm^-2, Willingale et al. 2013), with an excess column of 2.4
(+1.91/-1.72) x 10^21 cm^-2 (90% confidence). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 187 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 none of
the XRT error circle. 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 0.02. 

Burst Advocate for this burst is A. Melandri (andrea.melandri AT brera.inaf.it). 
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.)

A.P. Beardmore, P.A. Evans, M.R. Goad and J.P. Osborne (U. Leicester) 
report on behalf of the Swift-XRT team.

Using 2820 s of XRT Photon Counting mode data and 5 UVOT
images for GRB 141109B, 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 = 222.30317, +73.13085 which is equivalent
to:

RA (J2000): 14h 49m 12.76s
Dec (J2000): +73d 07' 51.1"

with an uncertainty of 1.5 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.

J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), A. Y. Lien (GSFC/UMBC),
C. B. Markwardt (GSFC), A. Melandri (INAF-OAB), D. M. Palmer (LANL),
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-60 to T+243 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 141109B (trigger #618032)
(Melandri, et al., GCN Circ. 17038
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 ).  The BAT ground-calculated position is
RA, Dec = 222.453, 73.141 deg, which is 
   RA(J2000)  =  14h 49m 48.8s 
   Dec(J2000) = +73d 08' 26.3" 
with an uncertainty of 2.6 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 75%.
 
The mask-weighted light curve shows a couple overlapping peaks starting at 
~T-20 sec, peaking at ~T+28 sec, and ending at ~T+60 sec.
T90 (15-350 keV) is 54.2 +- 5.0 sec (estimated error including systematics).
 
The time-averaged spectrum from T-13.18 to T+44.18 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.85 +- 0.22.  The fluence in the 15-150 keV band is 6.3 +- 0.9 x 10^-7 erg/cm2.
The 1-sec peak photon flux measured from T+28.05 sec in the 15-150 keV band
is 0.4 +- 0.1 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/618032/BA/

I.V. Sokolov, A. Moskvitin, V.V. Sokolov (SAO-RAS Zelenchukaja, Russia),
S. Guziy (Nikolaev Univ. Obs., Ukraine), A.J. Castro-Tirado, J.C. Tello
(IAA-CSIC Granada, Spain), Y. Fan, X. Zhao, J. Bai, Ch. Wang and Y. Xin
(Yunnan National Astronomical Observatory, China) on behalf of a larger
collaboration, report:

Following the detection of GRB 141109B by Swift/BAT (Melandri et al., GCNC
17038), the robotic 0.6m MET telescope at the BOOTES-4 station, in Lijiang
Astronomical Observatory (China) responded to the event after the sunset,
with the first images being obtained about 3.5 h post-burst. Additional
R-band images (6 x 300s) were taken at the 2.0m Terskol telescope in the
Northern Caucasus starting 11.3 hr post-burst. No optical source is
detected at the refined Swift/XRT position (Beardmore et al., GCNC 17045)
down to the DSS limit. Observations at longer wavelengths are encouraged.

M.C. Stroh (PSU), D.N. Burrows (PSU), K.L. Page (U. Leicester), C.
Pagani (U. Leicester), A.P. Beardmore (U. Leicester), B. Sbarufatti
(INAF-OAB/PSU), P. D'Avanzo (INAF-OAB), J.A. Kennea (PSU) and A.
Melandri report on behalf of the Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 141109B (Melandri  et al.
GCN Circ. 17038
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 ),  from 170 s to 70.7 ks after the  BAT trigger. The
data comprise 7 s in Windowed Timing (WT) mode (taken while Swift was
slewing), with the remainder in Photon Counting (PC) mode. The enhanced
XRT position for this burst was given by Beardmore et al. (GCN Circ.
17045
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 ).

The light curve can be modelled with an initial power-law decay with an
index of alpha=5.2 (+1.4, -1.1), followed by a break at T+291 s to an
alpha of 0.51 (+/-0.04).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.96 (+0.16, -0.15). The
best-fitting absorption column is  9.8 (+4.2, -3.8) x 10^20 cm^-2, in
excess of the Galactic value of 2.5 x 10^20 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 3.4 x 10^-11 (4.1 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     9.8 (+4.2, -3.8) x 10^20 cm^-2
Galactic foreground: 2.5 x 10^20 cm^-2
Excess significance: 3.2 sigma
Photon index:	     1.96 (+0.16, -0.15)

If the light curve continues to decay with a power-law decay index of
0.51, the count rate at T+24 hours will be 0.034 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.1 x
10^-12 (1.4 x 10^-12) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00618032.

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

A. J. Castro-Tirado, J. C. Tello (IAA-CSIC Granada), A. Monfardini
(NEEL-CNRS Grenoble), R. Adam, B. Comis (LPSC Grenoble), N. Ponthieu
(Univ. of Grenoble), C. Kramer and I. Hermelo (IRAM Granada), on behalf of
a larger collaboration, report:

Following the detection of GRB 141109B by Swift (Melandri et al. GCNC
17038), observations with the IRAM 30m antenna (+NIKA) at Pico Veleta
(Spain) were triggered on 9 Nov under good conditions but at relatively
low elevation (25 deg). At the position of the X-ray afterglow (Beardmore
et al. GCNC 17045), we detect no mm afterglow (at 150 GHz) down to a
preliminary flux density of 1 mJy (3 sigma) on Nov 9, 20:30 UT (mid time).
We acknowledge excellent assistance from the IRAM observers.

Y.Ono, T. Yoshii, Y. Saito, Y. Tachibana, H. Ohuchi, Y. Yano,
S. Kurita, T. Fujiwara, Y. Yatsu, and N. Kawai (Tokyo Tech)
report on behalf of the MITSuME collaboration:

We observed the field of GRB 141109B (A.Melandri et al., GCN Circular #17038
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 ) 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 on 2014-11-09 18:57:42.8 UT (~11.2h after the burst).
We did not find any new point source within XRT circle in all three bands.

The measured magnitudes are listed below.

T0+[sec]      MID-UT      T-EXP[sec]         g'           Rc           Ic
---------------------------------------------------------------------------------------
  40320     19:52:29.1          780           >19.4      >19.0     > 18.4
---------------------------------------------------------------------------------------
T0+ : Elapsed time after the burst 
T-EXP: Total Exposure time 
We used GSC2.3 catalog for flux calibration.

F. E. Marshall (NASA/GSFC) and A. Melandri (INAF-OAB)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 141109B
188 s after the BAT trigger (Melandri et al., GCN Circ. 17038
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 ).
No optical afterglow consistent with the UVOT-enhanced XRT position
(Beardmore et al., GCN Circ. 17045
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 )
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           188          338          147         >20.1
u_FC               347          596          246         >20.4
white              188         6699          588         >21.3
v                  677         7110          313         >20.4
b                  602         6494          294         >21.0
u                  347        13125         1061         >20.9
w1                 727        12566         1207         >21.0
m2                 701         7315          255         >20.8
w2                 828         6905          255         >21.0

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.02 in the direction of the burst
(Schlegel et al. 1998).

E. Mazaeva (IKI), A. Stepura (UAFO, ISON),  R. Inasaridze (AAO),  B. 
Abdulloev (Institute of Astrophysics),   A. Matkin (UAFO, ISON), N. 
Minikulov (Institute of Astrophysics), A. Volnova (IKI), Molotov (KIAM), A. 
Pozanenko (IKI) report on behalf of  larger GRB follow-up collaboration:

We observed the field of the Swift GRB 141109B  (Melandri  et al., GCN 
17038
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 ) with following instruments: SANTEL-650 (0.65m) telescope of 
UAFO/ISON-Ussuriysk Observatory,  AZT-8 (0.7m) telescope of Gissar 
observatory, and AS-32 (0.7m) telescope of Abastumani Observatory  (AAO). In 
the enhanced XRT error circle (Beardmore  et al., GCN 17045
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 )  we do not 
detect any source with  upper limits listed below:

Date              UT start    t-T0            Filter   Exp.     UL(3sigma) 
Observatory
                                       (mid, days)           (s)

2014-11-09 09:18:51  0.10220    clear  100*60  20.7          UAFO
2014-11-09 14:30:43  0.29425    R          40*60  19.9          Gissar
2014-11-09 15:26:30  0.38464    clear    71*120 22.0         AAO


The photometry is based on  stars of USNO-B1.0 and assumed R magnitudes:
RA                 DEC                 R
222.429145 +73.085200    14.97
222.517839 +73.110348    15.54
222.193512 +73.123517    17.06
222.275356 +73.104562    17.46
222.463681 +73.158509    17.55