GRB 140705A

A. Arai, J. Takahashi, Y. Takagi, S. Honda, and K. Morihana (Univ. of Hyogo)
report on behalf of the Nayuta team and the OISTER collaboration:

We observed the field of GRB 140705A (Stamatikos et al., GCNC 16520)
with Nishiharima Infrared Camera (NIC) attached to the Nayuta 2-m
telescope at the Nishi-Harima Astronomical Observatory.

The observations were conducted on 2014-07-05 at 12:53:36 -- 13:06:20 UT.
We did not find any new point source within the enhanced XRT circle
(Osborne et al., GCNC 16521) in all three bands.

Three sigma upper limits of the object are listed below.
We used 2MASS catalog for flux calibration.

# MID-UT  T0+[day] T-EXP  J_mag   H_mag   Ks_mag
--------------------------------------------------------------------------------
12:59:59   0.14388   600   >16.6   >16.0   >15.4
--------------------------------------------------------------------------------
T0+: Elapsed time after the burst (day)
T-EXP: Total Exposure time (seconds)

-- 
-------------------------------------------------
Akira Arai,
Nishi-Harima Astronomical Observatory,
University of Hyogo
mail : arai@nhao.jp
-------------------------------------------------

W. Fong and E. Berger (Harvard) report:

"We observed the field of the Swift-detected SGR 1935+2154 (GRB 140705A;
Stamatikos et al., GCN 16520
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 ) with the Karl G. Jansky Very Large Array
(VLA) beginning on 2014 Jul 6.34 UT (22.69 hr after the BAT trigger) at a
mean frequency of 6 GHz. In 1 hour of observations, we do not detect any
radio emission within the enhanced XRT position (Osborne et al., GCN 16521
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 )
to a 3-sigma limit of 41 microJy."

B. M. Gaensler (U. Sydney / CAASTRO) reports:

I note that the newly identified magnetar SGR 1935+2154 (GCN 16522
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 ; ATel 6294) is coincident with the Galactic supernova remnant (SNR) G57.2+0.8 (Sun et al., 2011, A&A, 536, A83, and references therein).

Specifically, the location of the SGR as determined by Swift XRT (ATel 6294) sits very close to the geometric centre of the SNR. A 1.4 GHz radio image of the SNR taken from the VLA Galactic Plane Survey (Stil et al., 2006, AJ, 132, 1158), and showing the position of the SGR, is available at:

http://www.physics.usyd.edu.au/~bmg/fig_sgr1935+2154_snr.png

This is a relatively uncrowded region of the Galactic plane, implying a high probability of a physical association between SGR 1935+2154 and SNR G57.2+0.8. The SGR's location at the centre of a SNR is similar to that previously found for other SGRs such as 1E 2259+586 in CTB 109, 1E 1841-045 in Kes 73 and 1E 1547.0-5408 in G327.2-0.1.

No reliable age or distance estimate is available for SNR G57.2+0.8.

C. Guidorzi, S. Dichiara (U. Ferrara) on behalf of a large
collaboration report:

The 2-m Faulkes Telescope North began observing Swift GRB 140705A/
SGR 1935+2154 (Stamatikos et al. GCN Circ 16520
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 ; Lien et al. GCN Circ
16522
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 ) on July 05 at 10:10:46 UT, i.e. ~38 min after the BAT trigger,
with the r' and i' filters.

Within the enhanced XRT error circle (Osborne et al. GCN Circ. 16521
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 )
we found nothing down to the following limit:

Mid time from  Total Exp    Filter    Magnitude
trigger (min)   (s)
--------------------------------------------------------------
52.0            120x4       i'        > 21
--------------------------------------------------------------

Magnitudes are calibrated against nearby USNO-B1 stars.

A. de Ugarte Postigo (IAA-CSIC, DARK/NBI), J. Gorosabel (IAA-CSIC/UPV-EHU), P. Rodriguez-Gil (IAC) and S. Campana (INAF-OAB) report on behalf of a larger collaboration:

We have observed the field of GRB 140705A / SGR 1935+2154 (Stamatikos et al. GCN 16520
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 , Lien et al. GCN 16522
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 ) using OSIRIS on the 10.4m GTC telescope. Observations started at 00:57 UT of the 6 July 2014 (15.42 hrs after the burst onset) and consisted of 10x120s in i-band and 20x60s in z-band. Within the enhanced XRT error box (Osborne et al. GCN 16521
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 , updated to R.A.: 293.73169, Dec.: +21.89668, +/-1.5") we detect two sources. The first of them, which we name S1, has an approximate magnitude of i(AB)~24 whereas S2 has i(AB)~25.5. Photometry is based on USNO-B1.0, and is still very preliminary. The coordinates of these sources are (J2000+/-0.5"): 

S1: 19:34:55.56, +21:53:48.2
S2: 19:34:55.68, +21:53:47.9

We have used UKIDSS nIR images for comparison, as there were not deep enough images available in the optical (there is no SDSS coverage in this field). S1 is clearly detected in J, H and K-band images of UKIDSS. S2, could be marginally detected in J-band. At this point we cannot claim variability of any of these sources and thus their relation with GRB 140705A / SGR 1935+2154 cannot be stated.

We acknowledge excellent support from the GTC staff, in particular Riccardo Scarpa.

WeiKang Zheng, Alexei V. Filippenko, Adam Morgan (UC Berkeley), and
S. B. Cenko (NASA/Goddard Space Flight Center) report on behalf of the
KAIT GRB team:

The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, responded to Swift GRB 140705A (Stamatikos et al.,
GCN 16520
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 ) starting at 09:34:02 UT, 74 s after the burst.
Observations were performed with an automatic sequence in the
clear (roughly R), V, and I filters, and the exposure time was
20 s per image. We do not detect any new source within the enhanced 
XRT error circle (Osborne et al. GCN 16521
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 ) in our individual images, 
nor in the coadded images of the first 5 or 10 clear band images.
The typical limiting magnitude of our single clear image is about 
19.2 calibrated to USNO B1.0.

D. Kuroda (OAO, NAOJ),  H. Hanayama, T. Miyaji, J. Watanabe (IAO, NAOJ),
K. Yanagisawa (OAO, NAOJ), S.Nagayama (NAOJ), M. Yoshida (Hiroshima),
K. Ohta (Kyoto) and N. Kawai(Tokyo Tech)
report on behalf of the MITSuME and OISTER collaboration:

We observed the field of GRB 140705A (Stamatikos et al., GCNC 16520)
with the optical three color (g', Rc and Ic) CCD camera attached
to the Murikabushi 1m telescope of Ishigakijima Astronomical
Observatory.

The observation started on 2014-07-05 13:08:26 UT (~3.6 h after the burst).
We did not find any new point source within the enhanced XRT circle
(Osborne et al., GCNC 16521) in all the three bands.

Three sigma upper limits of the OT are listed below.
We used GSC2.3 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'     Rc     Ic
-----------------------------------------------------
0.20844    14:32:57    6960.0   >22.1  >21.5  >20.5
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

C. Pagani (U. Leicester), B. Sbarufatti (INAF-OAB/PSU), P. D'Avanzo
(INAF-OAB), V. D'Elia (ASDC), D.N. Burrows (PSU), J.A. Kennea (PSU), V.
Mangano (PSU), A.P. Beardmore (U. Leicester), P.A. Evans (U. Leicester)
and M. Stamatikos report on behalf of the Swift-XRT team:

We have analysed 10 ks of XRT data for GRB 140705A (Stamatikos	et al.
GCN Circ. 16520
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 ),  from 68 s to 35.0 ks after the  BAT trigger. The
data are entirely in Photon Counting (PC) mode. The enhanced XRT
position for this burst was given by Osborne et al. (GCN Circ. 16521
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 ).

The light curve can be modelled with  a power-law decay with a decay
index of alpha=0.15 (+0.09, -0.10).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 3.7 (+0.6, -0.5). The
best-fitting absorption column is  4.9 (+1.1, -1.0) x 10^22 cm^-2, in
excess of the Galactic value of 1.3 x 10^22 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.7 x 10^-11 (1.7 x 10^-09) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     4.9 (+1.1, -1.0) x 10^22 cm^-2
Galactic foreground: 1.3 x 10^22 cm^-2
Excess significance: 6.0 sigma
Photon index:	     3.7 (+0.6, -0.5)

If the light curve continues to decay with a power-law decay index of
0.15, the count rate at T+24 hours will be 0.022 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.0 x
10^-12 (3.7 x 10^-11) erg cm^-2 s^-1.

The results of the XRT-team automatic analysis are available at
http://www.swift.ac.uk/xrt_products/00603488.

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

D. Kuroda, K. Yanagisawa, Y. Shimizu, H. Toda (OAO, NAOJ),
S. Nagayama (NAOJ), M. Yoshida (Hiroshima), K. Ohta (Kyoto)
and N. Kawai(Tokyo Tech)
report on behalf of MITSuME and OISTER collaboration:

We observed the field of GRB 140705A (Stamatikos et al., GCNC 16520)
with the optical three color (g', Rc and Ic) CCD camera attached
to the MITSuME 50cm telescope of Okayama Astrophysical Observatory.

The observation started on 2014-07-05 14:57:48 UT (~5.4 h after the burst).
We did not find any new point source within the enhanced XRT circle
(Osborne et al., GCNC 16521) in all the three bands.

Three sigma upper limits of the OT are listed below.
We used GSC2.3 catalog for flux calibration.

#T0+[day]  MID-UT    T-EXP[sec]   g'     Rc     Ic
-----------------------------------------------------
0.30500    16:52:00    6540.0   >19.4  >19.1  >18.2
-----------------------------------------------------
T0+ : Elapsed time after the burst [day]
T-EXP: Total Exposure time [sec]

[GCN OPS NOTE(06jul14): The Subject-line was changed to the correct GRB name.]

M. M. Chester (PSU) and M. Stamatikos (OSU/NASA/GSFC)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 140705A
65 s after the BAT trigger (Stamatikos et al., GCN Circ. 16520
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 ).
No optical afterglow consistent with the XRT position (Osborne et al. 
GCN Circ. 16521
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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            65          215          147         >20.6
u_FC               277          527          246         >20.2
white               65         6023          498         >21.5
v                  607         6434          432         >19.8
b                  532         7088          268         >21.1
u                  277         7048          659         >20.6
w1                 656         6843          432         >20.6
m2                5004         6638          393         >20.9
w2                 582         6229          432         >21.8

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 4.88 in the direction of the burst
(Schlegel et al. 1998).

A. Y. Lien (NASA/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC),
J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA),
C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (AGU), M. Stamatikos (OSU),
J. Tueller (GSFC), T. N. Ukwatta (MSU)
(i.e. the Swift-BAT team):

Using the data set from T-61 to T+242 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 140705A (trigger #603488)
(Stamatikos, et al., GCN Circ. 16520
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 ).  The BAT ground-calculated position is
RA, Dec = 293.751, 21.912 deg which is 
  RA(J2000)  =  19h 35m 00.3s 
  Dec(J2000) = +21d 54' 41.7" 
with an uncertainty of 1.4 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 94%.

The 2 ms mask-weighted light curve shows at least two spikes peaking at 
T+0 sec and T+0.05 sec.  T90 (15-350 keV) is 0.08 +- 0.01 sec (estimated 
error including systematics).

The time-averaged spectrum from T-0.02 to T+0.06 sec fit by a simple
power-law model shows the power law index of 2.74 +- 0.15 (chi squared 75.65 for 57 d.o.f.).
The fluence in the 15-150 keV band is 3.8 +- 0.4 x 10^-8 erg/cm2.
The 1-sec peak photon flux measured from T-0.48 sec in the 15-150 keV band
is 0.9 +- 0.2 ph/cm2/sec.

A single blackbody fit to the time-averaged spectrum shows the blackbody
temperature of 8.2 +- 1.0 keV (chi squared 74.30 for 57 d.o.f.).
A thermal bremsstrahlung model fit shows the temperature of 35.7 +- 6.1 keV
(chi squared 56.05 for 57 d.o.f.).  A double blackbody fit shows the lower temperature
of 4.8 +1.3 keV and the higher temperature of 13.7 (error not unconstrained) keV
(chi squared 54.60 for 55 d.o.f.).  All the quoted errors are at the 90% confidence level. 

Because 1) the burst is located at the galactic plane (l, b) = (57.25 deg, 0.83 deg.) and 
2) the BAT burst spectrum is rather soft, we believe this could be a short event from 
a newly discovered SGR 1935+2154.  

The results of the batgrbproduct analysis are available at
http://gcn.gsfc.nasa.gov/notices_s/603488/BA/

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

Using 886 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 140705A, 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 = 293.73199, +21.89673 which is equivalent
to:

RA (J2000): 19h 34m 55.68s
Dec (J2000): +21d 53' 48.2"

with an uncertainty of 2.3 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.

M. Stamatikos (OSU/NASA/GSFC), D. Malesani (DARK/NBI),
K. L. Page (U Leicester) and T. Sakamoto (AGU) report on behalf of the
Swift Team:

At 09:32:48 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 140705A (trigger=603488).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 293.725, +21.899 which is 
   RA(J2000) = 19h 34m 54s
   Dec(J2000) = +21d 53' 57"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a short spike 
with a duration of about 0.2 sec.  The peak count rate
was ~4500 counts/sec (15-350 keV), at ~0 sec after the trigger. 

The XRT began observing the field at 09:33:49.6 UT, 61.0 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source with an enhanced position: RA, Dec 293.7318, 21.8979 which
is equivalent to:
   RA(J2000)  = 19h 34m 55.64s
   Dec(J2000) = +21d 53' 52.4"
with an uncertainty of 2.9 arcseconds (radius, 90% containment). This
location is 23 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. 

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 64 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 large, but uncertain extinction expected. 

Burst Advocate for this burst is M. Stamatikos (Michael.Stamatikos-1 AT nasa.gov). 
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.)