GRB 191122A

B. Sbarufatti (PSU), A. P. Beardmore (U Leicester), J.D. Gropp (PSU),
J. A. Kennea (PSU), H. A. Krimm (NSF), N. P. M. Kuin (UCL-MSSL),
S Laha (GSFC/UMBC/CRESST) and A. Tohuvavohu (U Toronto) report on
behalf of the Neil Gehrels Swift Observatory Team:

At 13:32:56 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 191122A (trigger=938899).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 54.296, -32.176 which is 
   RA(J2000) = 03h 37m 11s
   Dec(J2000) = -32d 10' 32"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a single-peaked
structure with a duration of about 50 sec.  The peak count rate
was ~1200 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 13:34:31.1 UT, 94.7 seconds after
the BAT trigger. Using promptly downlinked data we find a bright,
fading, uncatalogued X-ray source located at RA, Dec 54.26926,
-32.18602 which is equivalent to:
   RA(J2000)  = 03h 37m 04.62s
   Dec(J2000) = -32d 11' 09.7"
with an uncertainty of 3.7 arcseconds (radius, 90% containment). This
location is 89 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. No
spectrum from the promptly downlinked event data is yet available to
determine the column density. 

The initial flux in the 2.5 s image was 1.89e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 103 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 B. Sbarufatti (bxs60 AT psu.edu). 
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/)

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

Using  promptly downlinked XRT event data for GRB 191122A, we find an
enhanced XRT position of the afterglow: RA, Dec: 54.2703, -32.1864
which is equivalent to:
   RA (J2000)  = 03 37 04.86
   Dec (J2000) = -32 11 10.9
with an uncertainty of 2.0 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/938899.

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.

Tianrui Sun, Chen Zhang, Yiding Ping, Xuefeng Wu (PMO).

We report the observations for the GRB191122A (B. Sbarufatti et al., GCN Circ 26269
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 ).
We use the 80cm telescope of CHanging Event Survey at the YaoAn observation station(101.1811E, 25.528N) in Yunnan Province, China. 

Our observation starts at  13:48:57 UT and ends at 13:54:24 UT Nov 22, 2019, with five exposure 60 seconds in white filter.
We do not detect any candidate sources in the combined image in the enhanced XRT position error region to a 5 sigma limit at 18.31 generated from G band magnitude in Gaia DR2 .

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

Using 4899 s of XRT Photon Counting mode data and 11 UVOT
images for GRB 191122A, 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 = 54.26986, -32.18665 which is equivalent
to:

RA (J2000): 03h 37m 4.77s
Dec (J2000): -32d 11' 11.9"

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.

Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado (IAA-CSIC), C. Perez 
del Pulgar, A. Castellon, I. Carrasco (Univ. de Malaga),�� S. Guziy 
(Univ. of Nikolaev) and D. Xiong, Y. Fan, X. Zhao, J. Bai, C. Wang, Y. 
Xin (Yunnan Nacional Astronomical Observatory) on behalf of a larger 
collaboration, report:

Following the detection of GRB 191122A by Swift (Sbarufatti et al. GCNC 
26269), the 0.6m BOOTES-4/MET robotic telescope at Lijiang Astronomical 
Observatory (China) started to gather images at 13:34 UT (~94s after 
trigger). No optical afterglow is found down to 20.3 mag (unfiltered 
images) at the enhaced Swift/XRT position (Evans et al. GCNC 26270), 
consistent with the non-detections by Swift/UVOT (Sbarufatti et al. GCNC 
26269) and CHES (Sun et al. GCNC 26271). Observations are ongoing."

We thank the staff at Lijiang Astronomical Observatory for their 
excellent support.

A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester), V. D'Elia
(ASDC), A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea
(PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester) and B.
Sbarufatti report on behalf of the Swift-XRT team:

We have analysed 8.8 ks of XRT data for GRB 191122A (Sbarufatti et al.
GCN Circ. 26269
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 ), from 301 s to 23.9 ks after the  BAT trigger. The
data are entirely in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Evans et al. (GCN Circ. 26270
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 ).

The light curve can be modelled with a series of power-law decays. The
initial decay index is alpha=0.97 (+0.26, -0.31). At T+746 s  the decay
steepens to an alpha of 1.94 (+0.26, -0.10) before breaking again at
T+6109 s to a final decay with index alpha=-0.1 (+/-0.4).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 1.06 (+0.04, -0.03). The
best-fitting absorption column is  consistent with the Galactic value
of 1.0 x 10^20 cm^-2 (Willingale et al. 2013). The PC mode spectrum has
a photon index of 1.12 (+0.08, -0.07) and a best-fitting absorption
column consistent with the Galactic value. The counts to observed
(unabsorbed) 0.3-10 keV flux conversion factor deduced from this
spectrum  is 5.6 x 10^-11 (5.6 x 10^-11) erg cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     10.0 (+15.8, -0.0) x 10^19 cm^-2
Galactic foreground: 1.0 x 10^20 cm^-2
Excess significance: <1.6 sigma
Photon index:	     1.12 (+0.08, -0.07)

If the light curve continues to decay with a power-law decay index of
-0.1, the count rate at T+24 hours will be 0.067 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 3.8 x
10^-12 (3.8 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/00938899.

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

H. A. Krimm (NSF), S. D. Barthelmy (GSFC),  S. Laha (GSFC/UMBC),
A. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Sakamoto (AGU), B. Sbarufatti (PSU), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):

Using the data set from T-239 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 191122A (trigger #938899)
(Sbarufatti, et al., GCN Circ. 26269
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 ).  The BAT ground-calculated position is
RA, Dec = 54.290, -32.176 deg which is 
   RA(J2000)  =  03h 37m 09.7s 
   Dec(J2000) = -32d 10' 35.4" 
with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 26%.

The mask-weighted light curve shows a single FRED-shaped pulse rising from 
T-20 sec to T+0 sec, then decaying out to roughly T+250 sec.
T90 (15-350 keV) is 153.3 +- 38.3 sec (estimated error including systematics).

The time-averaged spectrum from -11.2 to 245.4 sec is best fit by a power law
with an exponential cutoff.  This fit gives a photon index 1.24 +- 0.28, 
and Epeak of 89.2 +- 41.9 keV (chi squared 69.11 for 56 d.o.f.).  For this
model the total fluence in the 15-150 keV band is 6.6 +- 0.3 x 10^-6 erg/cm2
and the 1-sec peak flux measured from T+6.44 sec in the 15-150 keV band is
3.1 +- 0.4 ph/cm2/sec.  A fit to a simple power law gives a photon index
of 1.67 +- 0.07 (chi squared 76.48 for 57 d.o.f.).  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/938899/BA/

N. P. M. Kuin (UCL-MSSL) and B. Sbarufatti (PSU)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 191122A
104 s after the BAT trigger (Sbarufatti et al., GCN Circ. 26269
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 ).
No optical afterglow consistent with the XRT position
(Evans GCN Circ. 26270
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 ,26272
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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           104          253          147         >21.1
u_FC               316          566          246         >20.4
white              104        11801         1305         >22.0
v                  647         6097          432         >20.2
b                  572        10938         1121         >21.9
u                  316         6696          642         >20.5
w1                 696         6508          413         >20.1
m2                 846         6303          413         >21.2
w2                 797         5893          413         >20.1

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).