GRB 220714B

The Fermi GBM team reports the detection of a likely LONG GRB

At 13:58:06 UT on 14 Jul 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220714B (trigger 679499891.272708 / 220714582).

The on-ground calculated location, using the Fermi GBM trigger data, is RA = 45.9, Dec = -22.6 (J2000 degrees, equivalent to J2000 03h 03m, -22d 36'), with a statistical uncertainty of 2.8 degrees.

The angle from the Fermi LAT boresight is 124.0 degrees.

The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220714582/quicklook/glg_skymap_all_bn220714582.png

The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220714582/quicklook/glg_healpix_all_bn220714582.fit

The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220714582/quicklook/glg_lc_medres34_bn220714582.gif

S. Laha (GSFC/UMBC), R. Brivio (INAF-OAB), P. D'Avanzo (INAF-OAB),
S. Dichiara (PSU), M. Ferro (INAF-OAB), J.D. Gropp (PSU),
N. J. Klingler (GSFC/UMBC/CRESSTII), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), K. L. Page (U Leicester), D. M. Palmer (LANL),
T. M. Parsotan (GSFC/UMBC/CRESSTII), T. Sbarrato (INAF-OAB),
B. Sbarufatti (INAF-OAB), M. H. Siegel (PSU) and M. A. Williams (PSU)
report on behalf of the Neil Gehrels Swift Observatory Team:

At 13:58:04 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220714B (trigger=1116221).  Swift slewed immediately to the burst. 
The BAT on-board calculated location is 
RA, Dec 47.072, -19.334 which is 
   RA(J2000) = 03h 08m 17s
   Dec(J2000) = -19d 20' 02"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a complex
structure with a duration of about 40 sec.  The peak count rate
was ~5500 counts/sec (15-350 keV), at ~13 sec after the trigger. 

The XRT began observing the field at 13:59:20.9 UT, 76.4 seconds after
the BAT trigger. XRT found a bright, uncatalogued X-ray source located
at RA, Dec 47.0803, -19.3269 which is equivalent to:
   RA(J2000)  = 03h 08m 19.27s
   Dec(J2000) = -19d 19' 36.8"
with an uncertainty of 5.2 arcseconds (radius, 90% containment). This
location is 38 arcseconds from the BAT onboard position, within the BAT
error circle. No event data are yet available to determine the column
density using X-ray spectroscopy. 

The initial flux in the 2.5 s image was 1.70e-09 erg cm^-2 s^-1 (0.2-10
keV). 

UVOT took a finding chart exposure of  56 seconds with the White filter
starting 121 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 position. Data from the list of sources generated
on-board are not available at this time. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.032. 

Burst Advocate for this burst is S. Laha (sib.laha AT gmail.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/)

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

Using 1471 s of XRT Photon Counting mode data and 4 UVOT
images for GRB 220714B, 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 = 47.08386, -19.32962 which is equivalent
to:

RA (J2000): 03h 08m 20.13s
Dec (J2000): -19d 19' 46.6"

with an uncertainty of 2.1 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.

F.E. Marshall (NASA/GSFC) and S. Laha (GSFC/UMBC) report on behalf of the Swift team:

UVOT took a finding chart exposure of 150 seconds with the White filter
starting 3552 seconds after the BAT trigger. There is a candidate afterglow in
the rapidly available 2.7'x2.7' sub-image at
  RA(J2000)  =     03:08:20.18 =  47.08409
  DEC(J2000) = -19:19:45.3  = -19.32925
with a 90%-confidence error radius of about 0.61 arc sec. This position is 1.5
arc sec. from the center of the XRT error circle (Evans et al. GCN Circ. 32395
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 ). The estimated magnitude is
16.52 with a 1-sigma error of about  0.14. No correction has been made for the
expected extinction corresponding to E(B-V) of 0.032.

M. Perri (SSDC & INAF-OAR), V. D'Elia (SSDC & INAF-OAR), A. D'Ai
(INAF-IASFPA), J.A. Kennea (PSU), A. Tohuvavohu (U. Toronto), B.
Sbarufatti (PSU), P.A. Evans (U. Leicester), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester) and S. Laha report on behalf of
the Swift-XRT team:

We have analysed 6.0 ks of XRT data for GRB 220714B (Laha et al. GCN
Circ. 32393
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 ), from 71 s to 45.6 ks after the  BAT trigger. The data
comprise 135 s in Windowed Timing (WT) mode (the first 4 s were taken
while Swift was slewing) with the remainder in Photon Counting (PC)
mode. The enhanced XRT position for this burst was given by Evans et
al. (GCN Circ. 32395
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 ).

The late-time light curve (from T0+3.5 ks) can be modelled with a
power-law decay with a decay index of alpha=1.22 (+/-0.04).

A spectrum formed from the WT mode data can be fitted with an absorbed
power-law with a photon spectral index	of 3.95 (+0.19, -0.18). The
best-fitting absorption column is  2.7 (+/-0.3) x 10^21 cm^-2, in
excess of the Galactic value of 3.2 x 10^20 cm^-2 (Willingale et al.
2013). The PC mode spectrum has a photon index of 2.03 (+/-0.10) and a
best-fitting absorption column of 1.47 (+0.28, -0.27) x 10^21 cm^-2.
The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor
deduced from this spectrum  is 3.4 x 10^-11 (4.4 x 10^-11) erg cm^-2
count^-1. 

A summary of the PC-mode spectrum is thus:
Total column:	     1.47 (+0.28, -0.27) x 10^21 cm^-2
Galactic foreground: 3.2 x 10^20 cm^-2
Excess significance: 7.0 sigma
Photon index:	     2.03 (+/-0.10)

If the light curve continues to decay with a power-law decay index of
1.22, the count rate at T+24 hours will be 0.059 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 2.0 x
10^-12 (2.6 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/01116221.

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

R. Strausbaugh (U. of the Virgin Islands), A. Cucchiara (College of Marin) report on behalf of a larger collaboration:

We observed the Swift GRB 220714B (Laha et al., GCN 32393
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 ) field with the LCO 1-meter Sinistro instrument at the South African Astronomical Observatory site, on July 15, from 02:32 to 02:59 UT (corresponding to 13.57 to 14.02 hours from the GRB trigger time) with the SDSS r and i filters.

We performed a series of 3x300s exposures in i and r bands.  We detect an optical counterpart at the same position as the UVOT afterglow (Marshall et al., GCN 32396
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 ) in both bands.

The following magnitudes are calculated using the PanSTARRS catalog as reference:

r = 19.77 +/- 0.07
i = 19.44 +/- 0.07

These magnitudes are not corrected for galactic extinction.

R.S. is funded by NSF AST grant #1831682

S. Dalessi (UAH), C. Fletcher (USRA) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 13:58:06.27 UT on 14 July 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220714B (trigger 679499891 / 220714582)
which was also detected by the Swift/BAT (S. Laha et al. 2022, GCN 32393
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 )
The Fermi GBM Final Real-time Localization (GCN 32392
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 ) is consistent
with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 121 degrees.

The GBM light curve consists of multiple peaks
with a duration (T90) of about 28 s (50-300 keV).
The time-averaged spectrum from T0-3.07 s to T0+26.6 s is
well by a power law function with an exponential
high-energy cutoff.  The power law index is -1.63 +/- 0.06 and
the cutoff energy, parameterized as Epeak, is 139 +/- 24 keV

The event fluence (10-1000 keV) in this time interval is
(8.0 +/- 0.4)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+11.0 s in the 10-1000 keV band
is 6.5 +/- 0.4 ph/s/cm^2.

The spectral analysis results presented above are preliminary;
final results will be published in the GBM GRB Catalog:
https://heasarc.gsfc.nasa.gov/W3Browse/fermi/fermigbrst.html

For Fermi GBM data and info, please visit the official Fermi GBM Support Page:
https://fermi.gsfc.nasa.gov/ssc/data/access/gbm/"

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

Using the data set from T-173 to T+963 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220714B (trigger #1116221)
(Laha, et al., GCN Circ. 32393
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 ).  The BAT ground-calculated position is
RA, Dec = 47.086, -19.321 deg which is
   RA(J2000)  =  03h 08m 20.7s
   Dec(J2000) = -19d 19' 13.8"
with an uncertainty of 1.3 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 88%.

The mask-weighted light curve shows a complex structure.  The main period of
emission starts around T-5 sec and continues to T+35 seconds with three main
overlapping pulses.  There is some precursor activity starting as early as T-45
seconds and low-level emission extending to T+60 seconds.  The spacecraft
slewed away from the burst location at around T+275 seconds.
T90 (15-350 keV) is 50.10 +- 7.96 sec (estimated error including systematics).

The time-averaged spectrum from -48.27 to +45.75 sec is best fit by a simple
power-law model.  The power law index of the time-averaged spectrum is
1.92 +- 0.07.  The fluence in the 15-150 keV band is 4.4 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T+12.89 sec in the 15-150 keV band
is 3.8 +- 0.2 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/1116221/BA/

N. P. M. Kuin (UCL-MSSL) and S. Laha (NASA/UMCP) report on behalf of the
Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 220714B
3628 s after the BAT trigger (Laha et al, GCN Circ. 32393
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 ) and
detected a bright afterglow (Marshall & Laha, GCN Circ. 32396
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 ).
Marshal and Laha provided the UVOT position of GRB 220714B.
Perhaps due to a bright nearby star in the field, there were some
exposures which were cut short, but in this report we include those
using the UVOT photometric system (Breeveld et al. 2011, AIP Conf.
Proc. 1358, 373):

Filter            Time        Exp(s)         Mag

white              150           55          18.0 +/- 0.1
white             3628          147          16.53+/- 0.03
v                 3810          197          16.79+/- 0.09
m2                4115          197          16.42+/- 0.08
w1                4220          197          16.41+/- 0.06
u                 4425          197          16.33+/- 0.04
b                 4630          197          17.26+/- 0.05
white             4835          197          16.86+/- 0.03
w2                4992          102          17.16+/- 0.12
v                 5897           18          17.4 +/- 0.6

The magnitudes in the table are not corrected for the Galactic
extinction due to the reddening of E(B-V) = 0.032 in the direction of
the burst (Schlegel et al. 1998).