GRB 220715B
GCN Circular 32404
Subject
GRB 220715B: Fermi GBM Final Real-time Localization
Date
2022-07-15T22:35:09Z (3 years ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
The Fermi GBM team reports the detection of a likely LONG GRB
At 22:24:42 UT on 15 Jul 2022, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 220715B (trigger 679616687.73956 / 220715934).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 221.7, Dec = -36.4 (J2000 degrees, equivalent to J2000 14h 46m, -36d 23'), with a statistical uncertainty of 16.5 degrees.
The angle from the Fermi LAT boresight is 87.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220715934/quicklook/glg_skymap_all_bn220715934.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/bn220715934/quicklook/glg_healpix_all_bn220715934.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2022/bn220715934/quicklook/glg_lc_medres34_bn220715934.gif
GCN Circular 32405
Subject
GRB 220715B: Swift detection of a burst
Date
2022-07-15T22:39:06Z (3 years ago)
From
David Palmer at LANL <palmer@lanl.gov>
E. Troja (NASA/GSFC/UMCP), P. D'Avanzo (INAF-OAB), S. Dichiara (PSU),
M. Ferro (INAF-OAB), J.D. Gropp (PSU),
N. J. Klingler (GSFC/UMBC/CRESSTII), S. Laha (GSFC/UMBC),
A. Y. Lien (U Tampa), F. E. Marshall (NASA/GSFC),
A. Melandri (INAF-OAB), D. M. Palmer (LANL),
T. M. Parsotan (GSFC/UMBC/CRESSTII), T. Sbarrato (INAF-OAB) and
M. A. Williams (PSU) report on behalf of the Neil Gehrels Swift
Observatory Team:
At 22:24:42 UT, the Swift Burst Alert Telescope (BAT) triggered and
located GRB 220715B (trigger=1116441). Swift slewed immediately to the burst.
The BAT on-board calculated location is
RA, Dec 254.889, -33.597 which is
RA(J2000) = 16h 59m 33s
Dec(J2000) = -33d 35' 48"
with an uncertainty of 3 arcmin (radius, 90% containment, including
systematic uncertainty). The BAT light curve showed a multi-peaked
structure with a duration of about 50 sec. The peak count rate
was ~2400 counts/sec (15-350 keV), at ~0 sec after the trigger.
The XRT began observing the field at 22:26:20.9 UT, 98.8 seconds after
the BAT trigger. Using promptly downlinked data we find an uncatalogued
X-ray source located at RA, Dec 254.87520, -33.59766 which is
equivalent to:
RA(J2000) = 16h 59m 30.05s
Dec(J2000) = -33d 35' 51.6"
with an uncertainty of 5.7 arcseconds (radius, 90% containment). This
location is 41 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 https://www.swift.ac.uk/sper. We
cannot determine whether the source is fading at the present time.
A power-law fit to a spectrum formed from promptly downlinked event
data gives a column density consistent with the Galactic value of 3.58
x 10^21 cm^-2 (Willingale et al. 2013).
UVOT took a finding chart exposure of 150 seconds with the White filter
starting 102 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. Because of the density of
catalogued stars, further analysis is required to report an upper limit for any
afterglow in the region. No correction has been made for the expected
extinction corresponding to E(B-V) of 0.525.
Burst Advocate for this burst is E. Troja (nora.gsfc 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/)
GCN Circular 32406
Subject
GRB 220715B: Prompt enhanced Swift-XRT position
Date
2022-07-15T23:08:54Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
P.A. Evans (U. Leicester) reports on behalf of the Swift-XRT team:
Using promptly downlinked XRT event data for GRB 220715B, we find an
enhanced XRT position of the afterglow: RA, Dec: 254.87517, -33.59793
which is equivalent to:
RA (J2000) = 16 59 30.04
Dec (J2000) = -33 35 52.5
with an uncertainty of 1.9 arcseconds (radius, 90% confidence).
Analysis of the promptly available data is online at
http://www.swift.ac.uk/sper/1116441.
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.
GCN Circular 32407
Subject
Swift GRB 220715B: Global MASTER-Net observations report
Date
2022-07-16T00:10:43Z (3 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
V. Lipunov, V.Kornilov, E.Gorbovskoy, K.Zhirkov, N.Tyurina, P.Balanutsa, A.Kuznetsov, D. Vlasenko,
G.Antipov, D.Zimnukhov, V.Senik, E.Minkina, A.Chasovnikov, V.Topolev, D.Kuvshinov, D.Cheryasov, Ya.Kechin
(Lomonosov Moscow State University, SAI, Physics Department),
R. Podesta, C.Lopez, F. Podesta, C.Francile
(Observatorio Astronomico Felix Aguilar OAFA),
R. Rebolo, M. Serra
(The Instituto de Astrofisica de Canarias),
D. Buckley
(South African Astronomical Observatory),
O.A. Gres, N.M. Budnev
(Irkutsk State University, API),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez, A.R.Corella, L.H.Rodriguez
(INAOE, Guillermo Haro Astrophysics Observatory),
A. Tlatov, D. Dormidontov
(Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov
(Blagoveschensk Educational State University)
MASTER-OAFA robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in Argentina (OAFA observatory of San Juan National University) was pointed to the Swift GRB 220715B ( E. Troja et al., GCN 32405) errorbox 3230 sec after notice time and 3257 sec after trigger time at 2022-07-15 23:18:59 UT, with upper limit up to 15.1 mag. The observations began at zenith distance = 34 deg. The sun altitude is -18.7 deg.
The galactic latitude b = 5 deg., longitude l = 351 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2032406
We obtain a following upper limits.
Tmid-T0 | Site |Filt.| Expt. | Limit| Comment
_________|_____________________|_____|_______|______|________
3347 | MASTER-OAFA | C | 180 | 13.0 |
3746 | MASTER-OAFA | C | 180 | 14.5 |
3957 | MASTER-OAFA | C | 180 | 14.3 |
4168 | MASTER-OAFA | C | 180 | 13.5 |
4379 | MASTER-OAFA | C | 180 | 14.8 |
5784 | MASTER-OAFA | C | 180 | 15.1 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 32408
Subject
GRB 220715B: BOOTES-network optical upper limits
Date
2022-07-16T00:34:30Z (3 years ago)
From
Youdong HU at IAA-CSIC <huyoudong072@hotmail.com>
Y.-D. Hu, E. Fernandez-Garcia, A. J. Castro-Tirado, M.D. Caballero-Garcia, R. Sanchez-Ramirez, I. Perez-Garcia (IAA-CSIC), C. Perez del Pulgar, A. Castellon, M. A. Castro Tirado (Univ. de Malaga), R. Fernandez-Munoz (IHSM/UMA-CSIC), M. Jelinek (ASU-CAS) and F. Rendon (IAA-CSIC and INTA-CEDEA) on behalf of a larger collaboration, report:
Following the detection of GRB 220715B by both Swift (Troja et al., GCNC 32405) and Fermi (GBM team., GCNC 32404), the 0.3m BOOTES-1B robotic telescope in Mazagon (Huelva, Spain) automatically responded to this burst on Jul. 15 at 22:25:39 UT (i.e. ~57 s after trigger). In the co-added frame (30 x 10 s, clear filter), no source is detected within the enhanced XRT position (Evans et al., GCNC 32406) down to 16.1 mag.
Later on, the 0.6m BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) automatically pointed to the burst position at 22:26:07 UT (i.e. ~85 s after trigger). In the co-added image (25 x 10 s, clear filter), no optical afterglow is detected within the enhanced XRT position (Evans et al., GCNC 32406) down to 18.4 mag.
We note the expected high galactic extinction towards the burst location, in the direction of the Galactic Bulge.
We thank the staff at INTA-CEDEA and IHSM/UMA-CSIC La Mayora for their excellent support.
GCN Circular 32409
Subject
GRB 220715B: Enhanced Swift-XRT position
Date
2022-07-16T02:27:16Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
M.R. Goad, J.P. Osborne, A.P. Beardmore and P.A. Evans (U. Leicester)
report on behalf of the Swift-XRT team.
Using 1379 s of XRT Photon Counting mode data and 1 UVOT
images for GRB 220715B, 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 = 254.87532, -33.59775 which is equivalent
to:
RA (J2000): 16h 59m 30.08s
Dec (J2000): -33d 35' 51.9"
with an uncertainty of 2.5 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.
GCN Circular 32410
Subject
GRB 220715B: Swift/UVOT Upper Limits
Date
2022-07-16T08:26:04Z (3 years ago)
From
Paul Kuin at MSSL <npkuin@gmail.com>
N. P. M. Kuin (UCL-MSSL) and E. Troja (NASA/GSFC/UMCP)
report on behalf of the Swift/UVOT team:
The Swift/UVOT began settled observations of the field of GRB 220715B
103 s after the BAT trigger (Troja et al., GCN Circ. 32405).
No optical afterglow consistent with the XRT position
(Goad et al. GCN Circ. 32409)
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 103 253 147 >20.1
u_FC 316 565 246 >20.0
white 103 1369 373 >20.4
v 645 1419 97 >18.9
b 571 5005 274 >20.8
u 316 1488 319 >20.1
w1 695 1468 78 >18.8
m2 670 1443 97 >19.8
w2 621 5144 227 >19.9
The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.525 in the direction of the burst
(Schlegel et al. 1998).
GCN Circular 32411
Subject
GRB 220715B: Swift-XRT refined Analysis
Date
2022-07-16T09:05:07Z (3 years ago)
From
Phil Evans at U of Leicester <pae9@leicester.ac.uk>
V. D'Elia (SSDC & INAF-OAR), A. D'Ai (INAF-IASFPA), A. Tohuvavohu (U.
Toronto), B. Sbarufatti (PSU), D.N. Burrows (PSU), J.P. Osborne (U.
Leicester), K.L. Page (U. Leicester), A.P. Beardmore (U. Leicester), A.
Melandri (INAF-OAB) and E. Troja report on behalf of the Swift-XRT
team:
We have analysed 6.4 ks of XRT data for GRB 220715B (Troja et al. GCN
Circ. 32405), from 106 s to 29.2 ks after the BAT trigger. The data
are entirely in Photon Counting (PC) mode. The enhanced XRT position
for this burst was given by Goad et al. (GCN Circ. 32406).
The light curve can be modelled with a power-law decay with a decay
index of alpha=0.75 (+/-0.06).
A spectrum formed from the PC mode data can be fitted with an absorbed
power-law with a photon spectral index of 2.6 (+0.5, -0.4). The
best-fitting absorption column is 1.0 (+0.4, -0.3) x 10^22 cm^-2, in
excess of the Galactic value of 3.6 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 3.7 x 10^-11 (1.1 x 10^-10) erg
cm^-2 count^-1.
A summary of the PC-mode spectrum is thus:
Total column: 1.0 (+0.4, -0.3) x 10^22 cm^-2
Galactic foreground: 3.6 x 10^21 cm^-2
Excess significance: 3.2 sigma
Photon index: 2.6 (+0.5, -0.4)
If the light curve continues to decay with a power-law decay index of
0.75, the count rate at T+24 hours will be 4.7 x 10^-3 count s^-1,
corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.7 x
10^-13 (5.3 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/01116441.
This circular is an official product of the Swift-XRT team.
GCN Circular 32412
Subject
GRB 220715B: Fermi GBM detection
Date
2022-07-16T23:23:20Z (3 years ago)
From
Suraj Poolakkil at UAH <sp0076@uah.edu>
O.J. Roberts (USRA), S. Poolakkil (UAH) and C.Meegan (UAH)
report on behalf of the Fermi GBM Team:
"At 22:24:42.74 UT on 15 July 2022, the Fermi Gamma-Ray Burst Monitor (GBM)
triggered and located GRB 220715B (trigger 679616687 / 220715934), which was
also detected by the Swift/BAT (E. Troja et al. 2022, GCN 32405)
The Fermi GBM Final Real-time Localization (GCN 32404) is consistent with
the Swift position.
The angle from the Fermi LAT boresight at the GBM trigger time is 69
degrees.
The GBM light curve consists of multiple peaks
with a duration (T90) of about 40 s (50-300 keV).
The time-averaged spectrum from T0-1.024 s to T0+43.008 s is
best fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.09 +/- 0.23 and
the cutoff energy, parameterized as Epeak, is 118 +/- 28 keV.
The event fluence (10-1000 keV) in this time interval is
(2.2 +/- 0.3)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0-0.8 s in the 10-1000 keV band
is 2.5 +/- 0.2 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/"
GCN Circular 32414
Subject
GRB 220715B: Swift-BAT refined analysis
Date
2022-07-18T20:12:06Z (3 years ago)
From
Hans Krimm at NSF/NASA-GSFC <hkrimm@nsf.gov>
A. Y. Lien (U Tampa), S. D. Barthelmy (GSFC), H. A. Krimm (NSF),
S. Laha (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),
T. Parsotan (GSFC/UMBC), T. Sakamoto (AGU), M. Stamatikos (OSU),
E. Troja (NASA/GSFC/UMCP), (i.e. the Swift-BAT team):
Using the data set from T-240 to T+962 sec from the recent telemetry downlink,
we report further analysis of BAT GRB 220715B (trigger #1116441)
(Troja, et al., GCN Circ. 32405). The BAT ground-calculated position is
RA, Dec = 254.860, -33.586 deg which is
RA(J2000) = 16h 59m 26.5s
Dec(J2000) = -33d 35' 10.3"
with an uncertainty of 1.1 arcmin, (radius, sys+stat, 90% containment).
The partial coding was 95%.
The mask-weighted light curve shows an initial pulse with a FRED shape,
Beginning at just before T+0 and extending to about T+20. There is a second
weaker, softer pulse centered just after T+40 sec. There are a few gaps in the
light curve data, but none appear to correspond to burst activity.
T90 (15-350 keV) is 40.40 +- 1.24 sec (estimated error including systematics).
The time-averaged spectrum from T-0.15 to T+42.17 sec is best fit by a simple
power-law model. The power law index of the time-averaged spectrum is
1.36 +- 0.11. The fluence in the 15-150 keV band is 1.2 +- 0.1 x 10^-6 erg/cm2.
The 1-sec peak photon flux measured from T-0.08 sec in the 15-150 keV band
is 1.3 +- 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/1116441/BA/
GCN Circular 32422
Subject
GRB 220715B: VIRT Optical Upper Limit
Date
2022-07-24T02:17:46Z (3 years ago)
From
Priyadarshini Gokuldass at U. of the Virgin Islands <priyadass.94@gmail.com>
K. Noonan (UVI), P. Gokuldass (Florida Institute of Technology), N. Orange
(OrangeWave Innovative Science, LLC), K. Smith (UVI), R. Querrard (UVI), D.
Morris (UVI) report:
We observed the field of GRB220715B (Fermi GRB team, GCN 32404; and Troja
et al., GCN 32405) with the 0.5m Virgin Island Robotic Telescope (VIRT) at
the University of the Virgin Islands' Etelman Observatory on 07-16-2022
starting at 00:06:54 UT (T+1.7 hrs). We performed a series of exposures in
the R filter with a total exposure of 3910 s. The weather conditions were
partly cloudy during the hours of observation with an average airmass of
1.6.
We detect no new source within the enhanced XRT position error circle
(Evans et al., GCNC 32406), consistent with other non-detections (Lipunov
et al. GCN 32407, Hu et al, GCN 33408; and Kuin et al., GCN 32410) and
report the following 5-sigma upper limit:
T_mid ||Exposure ||Filter ||Limit
T+ 3.1 hrs ||3910s ||R ||>19.1
The limit is estimated from comparison to nearby USNO B1 stars and is not
corrected for Galactic extinction. The VIRT is still in the commissioning
phase.
We acknowledge financial support from NASA MUREP MIRO award 80NSSC21M0001,
NASA EPSCoR award 80NSSC19M0060, and NSF EiR award 1901296.This message can
be cited.