GRB 180704A

E. Sonbas (Adiyaman Univ.), A. D'Ai (INAF-IASFPA),
K. L. Page (U Leicester) and D. M. Palmer (LANL) report on behalf of
the Neil Gehrels Swift Observatory Team:

At 05:36:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 180704A (trigger=846088).  Swift did not immediately 
slew to the burst due to an Earth limb constraint. 
The BAT on-board calculated location is 
RA, Dec 32.638, +69.948 which is 
   RA(J2000) = 02h 10m 33s
   Dec(J2000) = +69d 56' 52"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex set
of peaks with a duration of about 25 sec.  The peak count rate
was ~4000 counts/sec (15-350 keV), at ~0 sec after the trigger. 

Due to an observing constraint, Swift will not slew until T0+48.1
minutes. There will be no XRT or UVOT data until this time. 

Burst Advocate for this burst is E. Sonbas (edasonbas AT yahoo.com). 
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.)

V. Lipunov, E. Gorbovskoy, V.Kornilov,  N.Tiurina, A.Kuznetsov, V.Chazov,
I. Gorbunov, D. Vlasenko, D.Zimnukhov, D.Kuvshinov, P.Balanutsa, V.Vladimirov
Lomonosov Moscow State University,SAI

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias (IAC)

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

R. Podesta, F. Podesta, C. Lopez, C.Francile
Observatorio Astronomico Felix Aguilar (OAFA)

H.Levato, Instituto de Ciencias Astronomicas, de la Tierra y del Espacio 
(ICATE)

D. Buckley
South African Astronomical Observatory

O. Gres, N.M.Budnev , Yu.Ishmuhametova
Irkutsk State University

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



MASTER-IAC robotic telescope (MASTER-Net: http://observ.pereplet.ru, 
Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in 
Spain (IAC Teide Observatory) was pointed to the Swift BAT GRB180704A 
(Sonbas et al. GCN 22885
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 ) 25 sec  after notice time and 41 sec after 
trigger time at 2018-07-04 05:37:23 UT. 
On our 10,20s exposure  set there is no optical transient  within SWIFT 
error-box (ra=32.6375 dec=69.9478 r=0.05).
The 5-sigma upper limit has been about 14.2mag
The message may be cited.


====================================================================



The observations made on zenit distance = 48 degrees, galaxy latitude b = 
8 degree.
The moon (70 % bright part) is 54 degrees above the horizon. The distance 
between  moon and  object is 83
Observations started at twilight.
The sun  altitude  is -7.5 degree, sunrise.

D.N. Burrows (PSU), J.A. Kennea (PSU), M. Perri (ASDC), G. Tagliaferri
(INAF-OAB), P.A. Evans (U. Leicester) and J.P. Osborne (U. Leicester)
report on behalf of the Swift-XRT team:

The XRT began observing the field of GRB 180704A at 06:26:11.9 UT,
2969.1 seconds after the BAT trigger. Using promptly downlinked data we
find an uncatalogued X-ray source with an enhanced position: RA, Dec
32.6592, 69.9641 which is equivalent to:
   RA(J2000)  = 02h 10m 38.22s
   Dec(J2000) = +69d 57' 50.7"
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 consistent with the Galactic value of 4.92
x 10^21 cm^-2 (Willingale et al. 2013).

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

Using 4046 s of XRT Photon Counting mode data and 7 UVOT
images for GRB 180704A, 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 = 32.66048, +69.96408 which is equivalent
to:

RA (J2000): 02h 10m 38.51s
Dec (J2000): +69d 57' 50.7"

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.

S.W.K. Emery (UCL-MSSL) and E. Sonbas (Adiyaman Univ.) and
A. A. Breeveld (UCL-MSSL)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180704A
3255 s after the BAT trigger (Sonbas et al., GCN Circ. 22885
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 ).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 22890
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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
exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white             3255         5455          537         >20.8
v                 4233        10567         1082         >19.8
b                 3618         5253          393         >19.9
u                 3413         5048          393         >19.6
uvw1                4643         4843          197         >19.2
uvm2                4438        11190          804         >20.3
uvw2                4028         9654         1082         >20.7

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.87 in the direction of the burst
(Schlegel et al. 1998).

C. B. Markwardt (GSFC), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),
H. A. Krimm (NSF/USRA), A. Y. Lien (GSFC/UMBC), D. M. Palmer (LANL),
T. Sakamoto (AGU), E. Sonbas (Adiyaman Univ.), M. Stamatikos (OSU),
T. N. Ukwatta (LANL) (i.e. the Swift-BAT team):
 
Using the data set from T-239 to T+760 sec from recent telemetry downlinks,
we report further analysis of BAT GRB 180704A (trigger #846088)
Sonbas, et al., GCN Circ. 22885
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 ).  The BAT ground-calculated position is
RA, Dec = 32.605, 69.965 deg, which is 
   RA(J2000)  =  02h 10m 25.1s 
   Dec(J2000) = +69d 57' 54.9" 
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 7%.
 
The mask-weighted light curve shows several peaks, the first starting at ~T-21 sec,
and the lagest peak at ~T+1 sec, with a long tail out to ~T+40 sec.
T90 (15-350 keV) is 19.7 +- 1.4 sec (estimated error including systematics).
 
The time-averaged spectrum from T-17.90 to T+4.24 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.22 +- 0.10.  The fluence in the 15-150 keV band is 6.2 +- 0.4 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+0.04 sec in the 15-150 keV band
is 9.6 +- 1.2 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/846088/BA/

Z. Liu (NAOC / U. Leicester), V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA),
A. Melandri (INAF-OAB), J.A. Kennea (PSU), B. Sbarufatti
(INAF-OAB/PSU), D.N. Burrows (PSU), J.P. Osborne (U. Leicester), K.L.
Page (U. Leicester) and E. Sonbas report on behalf of the Swift-XRT
team:

We have analysed 7.9 ks of XRT data for GRB 180704A (Sonbas et al. GCN
Circ. 22885
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 ), from 3.2 ks to 22.5 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. 22890
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 ).

The light curve can be modelled with an initial power-law decay with an
index of alpha=0.91 (+/-0.12), followed by a break at T+13.2 ks to an
alpha of 2.5 (+0.7, -0.6).

A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 1.92 (+0.14, -0.13). The
best-fitting absorption column is  8.3 (+1.2, -1.1) x 10^21 cm^-2, in
excess of the Galactic value of 4.9 x 10^21 cm^-2 (Willingale et al.
2013). The counts to observed (unabsorbed) 0.3-10 keV flux conversion
factor deduced from this spectrum  is 4.8 x 10^-11 (8.2 x 10^-11) erg
cm^-2 count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     8.3 (+1.2, -1.1) x 10^21 cm^-2
Galactic foreground: 4.9 x 10^21 cm^-2
Excess significance: 4.9 sigma
Photon index:	     1.92 (+0.14, -0.13)

If the light curve continues to decay with a power-law decay index of
2.5, the count rate at T+24 hours will be 2.1 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.0 x
10^-13 (1.8 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/00846088.

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

V. Sharma, A. Vibhute and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (TIFR) and S. Vadawale (PRL) report on behalf of the Astrosat CZTI collaboration:

Analysis of Astrosat CZTI data showed the detection of a long GRB 180704A, which was also detected by Swift-BAT (Sonbas E. et al., GCN 22885
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 ) and Swift-XRT (Burrows D. N. et al., GCN 22887
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 ).

The source was clearly detected in the 40-200 keV energy range. The light curve shows multiple peaks of emission with strongest peak at 05:36:43.500 UT. The measured peak count rate is 660.2 cts/s above the background in combined data of four quadrants, with a total of 5324 cts. The local mean background count rate was 571.8 cts/s. Using cumulative rates, we measure a T90 of 26 s. In preliminary analysis, we find that 463 compton events are associated with this event.

It was also clearly detected in the CsI anticoincidence (Veto) detector in the 100-500 keV energy range.

CZTI GRB detections are reported regularly on the payload site at http://astrosat.iucaa.in/czti/?q=grb. CZTI is built by a TIFR-led consortium of institutes across India, including VSSC, ISAC, IUCAA, SAC and PRL. The Indian Space Research Organisation funded, managed and facilitated the project.

D. Frederiks, S. Golenetskii, R.Aptekar, A. Kozlova,
A.Lysenko,  D. Svinkin, A. Tsvetkova,  M. Ulanov, and T. Cline,
on behalf of the Konus-Wind team, report:

The long GRB 180704A (Swift/BAT detection: Sonbas et al.,
GCN 22885
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 ; Markwardt et al., GCN 22894
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 ;
AstroSat CZTI detection: Sharma et al., GCN 22901
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 )
triggered Konus-Wind at T0=20182.254 s UT (05:36:22.254).

The KW light curve shows a multi-peaked structure with
a total duration of ~40 s. A possible precursor is
seen in the waiting mode data around T0 - 62 s.
The emission is seen up to ~4 MeV.

As observed by Konus-Wind, the burst had a fluence of
(1.8 �� 0.1)x10^-5 erg/cm2 and a 64-ms peak energy flux,
measured from T0+20.352, of (2.4 �� 0.2)x10^-6 erg/cm2
(both in the 20 keV - 10 MeV energy range).

The time-integrated spectrum (measured from T0 to T0+24.832 s)
is best fit in the 20 keV - 15 MeV range by a cutoff power-law
(CPL) function with the following model parameters:
the photon index alpha = -0.49(-0.13,+0.14),
and the peak energy Ep = 183(-11,+33) keV,
chi2 = 98/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and only an upper limit on beta (<-3.2).

The spectrum near the peak count rate (measured from T0+16.640
to T0+24.832 s) is best fit in the 20 keV - 15 MeV range by
the CPL function with the following model parameters:
the photon index alpha = -0.38(-0.20,+0.22),
and the peak energy Ep = 163(-13,+15) keV,
chi2 = 121/98 dof.
Fitting this spectrum with the GRB (Band) function yields
the same alpha and Ep, and only an upper limit on beta (<-3.2).

The Konus-Wind light curve of this GRB is available at
http://www.ioffe.ru/LEA/GRBs/GRB180704_T20182/

All the quoted errors are estimated at the 90% confidence level.
All the presented results are preliminary.