Gamma-ray Burst 201104A

(All information courtesy of the instrument teams.)

Previous IAU Circulars

none

Results of Observations

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 04 Nov 20 00:01:21 UT
NOTICE_TYPE:     Fermi-GBM Flight Position
RECORD_NUM:      46
TRIGGER_NUM:     626140861
GRB_RA:           89.233d {+05h 56m 56s} (J2000),
                  89.171d {+05h 56m 41s} (current),
                  89.383d {+05h 57m 32s} (1950)
GRB_DEC:         -70.600d {-70d 35' 59"} (J2000),
                 -70.598d {-70d 35' 53"} (current),
                 -70.603d {-70d 36' 11"} (1950)
GRB_ERROR:       5.70 [deg radius, statistical plus systematic]
GRB_INTEN:       818 [cnts/sec]
DATA_SIGNIF:     35.90 [sigma]
INTEG_TIME:      1.024 [sec]
GRB_DATE:        19157 TJD;   309 DOY;   20/11/04
GRB_TIME:        56.75 SOD {00:00:56.75} UT
GRB_PHI:         267.00 [deg]
GRB_THETA:        55.00 [deg]
DATA_TIME_SCALE: 1.0240 [sec]
HARD_RATIO:      0.47
LOC_ALGORITHM:   3 (version number of)
MOST_LIKELY:      95%  GRB
2nd_MOST_LIKELY:   4%  Generic Transient
DETECTORS:       0,0,0, 0,1,0, 0,0,1, 0,0,0, 0,0,
SUN_POSTN:       219.59d {+14h 38m 22s}  -15.44d {-15d 26' 38"}
SUN_DIST:         87.50 [deg]   Sun_angle= 8.7 [hr] (West of Sun)
MOON_POSTN:       78.16d {+05h 12m 38s}  +22.87d {+22d 52' 26"}
MOON_DIST:        93.80 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      281.05,-29.98 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      273.61,-85.95 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_lc_medres34_bn201104001.gif
COMMENTS:        Fermi-GBM Flight-calculated Coordinates.  
COMMENTS:        This trigger occurred at longitude,latitude = 88.15,-25.28 [deg].  
COMMENTS:        The LC_URL file will not be created until ~15 min after the trigger.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 04 Nov 20 00:01:39 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      58
TRIGGER_NUM:     626140861
GRB_RA:           59.520d {+03h 58m 05s} (J2000),
                  59.445d {+03h 57m 47s} (current),
                  59.707d {+03h 58m 50s} (1950)
GRB_DEC:         -73.750d {-73d 45' 00"} (J2000),
                 -73.691d {-73d 41' 27"} (current),
                 -73.891d {-73d 53' 26"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     48.70 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        19157 TJD;   309 DOY;   20/11/04
GRB_TIME:        56.75 SOD {00:00:56.75} UT
GRB_PHI:         266.00 [deg]
GRB_THETA:        65.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   4173 (Gnd S/W Version number)
SUN_POSTN:       219.59d {+14h 38m 22s}  -15.44d {-15d 26' 38"}
SUN_DIST:         89.94 [deg]   Sun_angle= 10.7 [hr] (West of Sun)
MOON_POSTN:       78.16d {+05h 12m 39s}  +22.87d {+22d 52' 28"}
MOON_DIST:        97.36 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      288.07,-37.49 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      311.47,-77.62 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_lc_medres34_bn201104001.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_626140861.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 04 Nov 20 00:02:12 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      2
TRIGGER_NUM:     626140861
GRB_RA:           58.280d {+03h 53m 07s} (J2000),
                  58.207d {+03h 52m 50s} (current),
                  58.462d {+03h 53m 51s} (1950)
GRB_DEC:         -73.850d {-73d 50' 59"} (J2000),
                 -73.789d {-73d 47' 19"} (current),
                 -73.996d {-73d 59' 45"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
DATA_SIGNIF:     48.70 [sigma]
DATA_INTERVAL:   4.096 [sec]
GRB_DATE:        19157 TJD;   309 DOY;   20/11/04
GRB_TIME:        56.75 SOD {00:00:56.75} UT
GRB_PHI:         266.00 [deg]
GRB_THETA:        65.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       219.59d {+14h 38m 22s}  -15.44d {-15d 26' 39"}
SUN_DIST:         89.96 [deg]   Sun_angle= 10.8 [hr] (West of Sun)
MOON_POSTN:       78.17d {+05h 12m 40s}  +22.88d {+22d 52' 31"}
MOON_DIST:        97.56 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      288.43,-37.72 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      311.55,-77.26 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_lc_medres34_bn201104001.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_626140861.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=8789).

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 04 Nov 20 00:10:21 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     626140861
GRB_RA:           60.380d {+04h 01m 31s} (J2000),
                  60.323d {+04h 01m 18s} (current),
                  60.522d {+04h 02m 05s} (1950)
GRB_DEC:         -72.740d {-72d 44' 23"} (J2000),
                 -72.683d {-72d 40' 56"} (current),
                 -72.877d {-72d 52' 37"} (1950)
GRB_ERROR:       1.00 [deg radius, statistical only]
GRB_DATE:        19157 TJD;   309 DOY;   20/11/04
GRB_TIME:        56.75 SOD {00:00:56.75} UT
GRB_PHI:         265.00 [deg]
GRB_THETA:        65.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       219.60d {+14h 38m 24s}  -15.45d {-15d 26' 45"}
SUN_DIST:         90.81 [deg]   Sun_angle= 10.6 [hr] (West of Sun)
MOON_POSTN:       78.24d {+05h 12m 58s}  +22.89d {+22d 53' 13"}
MOON_DIST:        96.34 [deg]
MOON_ILLUM:      90 [%]
GAL_COORDS:      286.84,-37.86 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      315.68,-78.17 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_lc_medres34_bn201104001.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_locplot_all_bn201104001.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice was generated completely by automated pipeline processing.  
COMMENTS:        Bright hard burst in the GBM.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:           
COMMENTS:        NOTE: This GBM event is temporally(1.0<100sec) coincident with the INTEGRAL_SPIACS event (trignum=8789).

GCN Circular #28823
The Fermi GBM team reports the detection of a likely LONG GRB
At 00:00:56 UT on 4 Nov 2020, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 201104A (trigger 626140861.749996 / 201104001).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 60.4, Dec = -72.7 (J2000 degrees, equivalent to J2000 04h 01m, -72d 42'), with a statistical uncertainty of 1.0 degrees.
The angle from the Fermi LAT boresight is 65.0 degrees.
The skymap can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_skymap_all_bn201104001.png
The HEALPix FITS file, including the estimated localization systematic, can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_healpix_all_bn201104001.fit
The GBM light curve can be found here: https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104001/quicklook/glg_lc_medres34_bn201104001.gif
GCN Circular #28824
V. Lipunov, E. Gorbovskoy, V.Kornilov, N.Tyurina, P.Balanutsa, A.Kuznetsov, F.Balakin, V.Vladimirov, D. Vlasenko, I.Gorbunov, D.Zimnukhov, V.Senik, T.Pogrosheva, D.Kuvshinov, D. Cheryasov (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, O.Ershova (Irkutsk State University, API),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
V. Yurkov, A. Gabovich, Yu. Sergienko (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) started inspect of the Fermi GRB 201104A ( Fermi GBM team, GCN 28823) errorbox 80 sec after trigger time at 2020-11-04 00:02:17 UT, with upper limit up to 17.8 mag. Observations started at twilight. The observations began at zenith distance = 59 deg. The sun altitude is -13.0 deg.
The galactic latitude b = -38 deg., longitude l = 287 deg.
Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1475503
We obtain a following upper limits.
```
Tmid-T0  |      Date Time      |          Site       |             Coord (J2000)          |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________


      90 | 2020-11-04 00:02:17 |         MASTER-OAFA | (03h 58m 14.15s , -74d 30m 15.1s) |   C |    20 | 17.4 |        
     130 | 2020-11-04 00:02:56 |         MASTER-OAFA | (03h 58m 07.55s , -74d 31m 15.8s) |   C |    20 | 17.3 |        
     174 | 2020-11-04 00:03:35 |         MASTER-OAFA | (03h 58m 15.37s , -74d 30m 56.0s) |   C |    30 | 17.4 |        
     228 | 2020-11-04 00:04:25 |         MASTER-OAFA | (03h 58m 11.98s , -74d 29m 19.8s) |   C |    40 | 17.6 |        
     293 | 2020-11-04 00:05:24 |         MASTER-OAFA | (03h 58m 12.40s , -74d 30m 55.2s) |   C |    50 | 17.8 |        
```
Filter C is a clear (unfiltred) band.
The observation and reduction will continue. The message may be cited.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 04 Nov 20 19:28:51 UT
NOTICE_TYPE:     Fermi-GBM Ground Position
RECORD_NUM:      1
TRIGGER_NUM:     626210610
GRB_RA:          238.000d {+15h 52m 00s} (J2000),
                 238.335d {+15h 53m 20s} (current),
                 237.199d {+15h 48m 48s} (1950)
GRB_DEC:         -34.420d {-34d 25' 11"} (J2000),
                 -34.481d {-34d 28' 51"} (current),
                 -34.271d {-34d 16' 14"} (1950)
GRB_ERROR:       6.81 [deg radius, statistical only]
DATA_SIGNIF:     11.20 [sigma]
DATA_INTERVAL:   17.408 [sec]
GRB_DATE:        19157 TJD;   309 DOY;   20/11/04
GRB_TIME:        69805.21 SOD {19:23:25.21} UT
GRB_PHI:           3.00 [deg]
GRB_THETA:        87.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       220.40d {+14h 41m 35s}  -15.69d {-15d 41' 29"}
SUN_DIST:         24.75 [deg]   Sun_angle= -1.2 [hr] (East of Sun)
MOON_POSTN:       88.81d {+05h 55m 15s}  +24.23d {+24d 13' 38"}
MOON_DIST:       151.66 [deg]
MOON_ILLUM:      85 [%]
GAL_COORDS:      340.20, 15.08 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      243.23,-13.91 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104808/quicklook/glg_lc_medres34_bn201104808.gif
POS_MAP_URL:     http://gcn.gsfc.nasa.gov/notices_f/gbm_gnd_loc_map_626210610.fits
COMMENTS:        Fermi-GBM Ground-calculated Coordinates.  
COMMENTS:        This is likely a Long GRB.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file will not be created/available until ~15 min after the trigger.  
COMMENTS:        The POS_MAP_URL file will not be created/available until ~1.5 min after the notice.

GCN NOTICE

TITLE:           GCN/FERMI NOTICE
NOTICE_DATE:     Wed 04 Nov 20 19:32:43 UT
NOTICE_TYPE:     Fermi-GBM Final Position
RECORD_NUM:      0
TRIGGER_NUM:     626210610
GRB_RA:          240.320d {+16h 01m 17s} (J2000),
                 240.663d {+16h 02m 39s} (current),
                 239.500d {+15h 58m 00s} (1950)
GRB_DEC:         -36.730d {-36d 43' 47"} (J2000),
                 -36.787d {-36d 47' 13"} (current),
                 -36.590d {-36d 35' 25"} (1950)
GRB_ERROR:       7.71 [deg radius, statistical only]
GRB_DATE:        19157 TJD;   309 DOY;   20/11/04
GRB_TIME:        69805.21 SOD {19:23:25.21} UT
GRB_PHI:           3.00 [deg]
GRB_THETA:        90.00 [deg]
E_RANGE:         44.032 - 279.965 [keV]
LOC_ALGORITHM:   41731 (Gnd S/W Version number)
SUN_POSTN:       220.40d {+14h 41m 36s}  -15.69d {-15d 41' 32"}
SUN_DIST:         27.72 [deg]   Sun_angle= -1.4 [hr] (East of Sun)
MOON_POSTN:       88.85d {+05h 55m 24s}  +24.23d {+24d 13' 50"}
MOON_DIST:       152.81 [deg]
MOON_ILLUM:      85 [%]
GAL_COORDS:      340.08, 12.10 [deg] galactic lon,lat of the burst (or transient)
ECL_COORDS:      245.65,-15.77 [deg] ecliptic lon,lat of the burst (or transient)
LC_URL:          http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104808/quicklook/glg_lc_medres34_bn201104808.gif
LOC_URL:         http://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2020/bn201104808/quicklook/glg_locplot_all_bn201104808.png
COMMENTS:        Fermi-GBM Final Position.  
COMMENTS:        This Notice was ground-generated -- not flight-generated.  
COMMENTS:        The LC_URL file should be available by the time this FINAL notice is produced.  
COMMENTS:        This notice was generated completely by automated pipeline processing.  
COMMENTS:        This is likely a Long GRB.

GCN Circular #28828
M. Ohno (Hiroshima U./Eotvos U.), N. Omodei (Stanford University), F. Longo (University & INFN Trieste) and M. Axelsson (KTH & Stockholm Univ.) report on behalf of the Fermi-LAT Collaboration:
On November 4, 2020, Fermi-LAT detected high-energy emission from GRB 201104A, which was also detected by Fermi-GBM (trigger 626140861/201104001) (Fermi-GBM team; GCN Circ. 28823).
The best LAT on-ground location is found to be
RA, Dec = 81.4, -71.1 (degrees, J2000)
with an error radius of 0.24 deg (90% containment, statistical error only). This was 6.7 deg from the LAT boresight at the time of the GBM trigger: T0 = 00:00:56 UT.
The source quickly went out from the LAT FoV but the data from the Fermi-LAT show a significant increase in the event rate after the GBM trigger that is spatially and temporally correlated with the GBM emission with high significance. The photon flux above 100 MeV in the time interval 0-100 s after the GBM trigger is (2.6+/-0.4)e-4 ph/cm2/s.
The estimated photon index above 100 MeV is -2.5 +/- 0.2.
The highest-energy photon is a 3.7 GeV event which is observed 16 seconds after the GBM trigger.
A Swift ToO has been requested for this burst
The Fermi-LAT point of contact for this burst is Masanori Ohno (ohno@astro.hiroshima-u.ac.jp).
The Fermi-LAT is a pair conversion telescope designed to cover the energy band from 20 MeV to greater than 300 GeV. It is the product of an international collaboration between NASA and DOE in the U.S. and many scientific institutions across France, Italy, Japan and Sweden.
GCN Circular #28829
A. Ursi (INAF/IAPS), F. Verrecchia, C. Pittori (SSDC, and INAF/OAR), M. Tavani (INAF/IAPS, and Univ. Roma Tor Vergata), A. Argan, M. Cardillo, C. Casentini, Y. Evangelista, G. Piano (INAF/IAPS), F. Lucarelli (SSDC, and INAF/OAR), A. Bulgarelli, V. Fioretti, F. Fuschino, N. Parmiggiani (INAF/OAS-Bologna), M. Marisaldi (INAF/OAS-Bologna, and Bergen University), M. Pilia, A. Trois (INAF/OA-Cagliari), I. Donnarumma (ASI), F. Longo (Univ. Trieste and INFN Trieste), A. Giuliani (INAF/IASF-Mi), report on behalf of the AGILE Team:
The AGILE Mini-CALorimeter (MCAL) detected GRB 201104A at T0 = 2020-11-04 00:00:56.77 +/- 0.01 s (UTC), reported by Fermi/GBM (GCN #28823) and INTEGRAL/SPI-ACS (trigger ID 8789,0).
The event lasted about 8 s and released a total number of ~7200 counts in the detector (in the 0.4-100 MeV energy range), above an average background rate of 640 Hz.
The light curve shows sveral episodes and can be found at http://www.agilescienceapp.it/notices/GRB_070287_531532856.770000.png .
The time-integrated spectrum of the burst can be fitted in the energy range 0.4-20 MeV with a single power-law with ph.ind. = -2.26 -0.15/+0.18, resulting in a reduced chi-squared of 1.06 (75 d.o.f.) and a fluence of 3.57e-06 ergs/cm^2 (90% confidence level), in the same energy range.
The burst is clearly visible in the AGILE scientific ratemeters of the MCAL detector. The event released a total number of 25100 counts, above a background rate of 1255 Hz. The AGILE ratemeter light curves can be found at http://www.agilescienceapp.it/notices/GRB_201104A_AGILE_RM.png .
The AGILE-MCAL detector is a CsI detector with a 4 pi FoV, sensitive in the energy range 0.4-100 MeV. Additional analysis of AGILE data is in progress. Automatic MCAL GRB alert Notices can be found at: https://gcn.gsfc.nasa.gov/agile_mcal.html.
GCN Circular #28830
E. Bissaldi (Politecnico and INFN Bari) and C. Malacaria (NASA-MSFC/USRA) report on behalf of the Fermi GBM Team:
"At 00:00:56.75 UT on 4 November 2020, the Fermi Gamma-Ray Burst Monitor (GBM) triggered and located GRB 201104A (trigger 626140861 / 201104001, which was also detected by the Fermi-LAT (Ohno et al. 2020, GCN 28828) and AGILE (Ursi et al. 2020, GCN 28829). The GBM on-ground location is consistent with the LAT position.
The angle from the Fermi LAT boresight at the GBM trigger time is 57 degrees.
The GBM light curve shows a bright emission episode with a duration (T90) of about 8.4 s (50-300 keV). The time-averaged spectrum from T0 to T0+9 s is best fit by a Band function with Epeak = 1140 +/- 130 keV, alpha = -0.76 +/- 0.04, and beta = -2.24 +/- 0.17.
The event fluence (10-1000 keV) in this time interval is (1.55 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured starting from T0 in the 10-1000 keV band is 12.1 +/- 0.3 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 #28832
P. A. Evans (U. Leicester) reports on behalf of the Swift team:
Swift has initiated a series of observations, tiled on the sky, of the Fermi/LAT GRB 201104A. Automated analysis of the XRT data will be presented online at http://www.swift.ac.uk/xrt_products/TILED_GRB00094
Any uncatalogued X-ray sources detected in this analysis will be reported on this website and via GCN COUNTERPART notices. The probability of finding serendipitous sources, unrelated to the Fermi/LAT event is high: any X-ray source considered to be a probable afterglow candidate will be reported via a GCN Circular after manual consideration.
Details of the XRT automated analysis methods are detailed in Evans et al. (2007, A&A, 469, 379; 2009, MNRAS, 397, 1177 and 2014, ApJS, 210, 8).
This circular is an official product of the Swift-XRT team.
GCN Circular #28834/#28837
F. Kunzweiler, B. Biltzinger, F. Berlato, J. Burgess & J. Greiner (all MPE Garching) report:
The public trigdat data of the Fermi Gamma-ray Burst Monitor (GBM) trigger 626140861 at 00:00:56 on 04 Nov. 2020 were automatically fitted for spectrum and sky location with BALROG (Burgess et al. 2018, MNRAS 476, 1427; Berlato et al. 2019, ApJ 873, 60).
The best-fit position (1 sigma statistical errors) is:
```
RA(2000.0) = 67.9+/-10.4 deg
Decl.(2000.0) = -73.2+/-1.6 deg
```
We estimate an additional systematic error of 2 deg.
Further details are available at: https://grb.mpe.mpg.de/grb/GRB201104001/
The Healpix map can be downloaded from: https://grb.mpe.mpg.de/grb/GRB201104001/healpix
The location parameters are available as JSON at: https://grb.mpe.mpg.de/grb/GRB201104001/json
GCN Circular #28859
V. D'Elia (ASDC), A. D'Ai (INAF-IASFPA), D.N. Burrows (PSU), J. D. Gropp (PSU), J.A. Kennea (PSU), A.P. Beardmore (U. Leicester), J.P. Osborne (U. Leicester), A. Melandri (INAF-OAB) and P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the Fermi/LAT-detected burst GRB 201104A (Ohno et al. GCN Circ. 28828) in a series of observations tiled on the sky. The total exposure time is 4.7 ks, distributed over 3 tiles; the maximum exposure at a single sky location was 2.4 ks. The data were collected between T0+67.6 ks and T0+80.9 ks, and are entirely in Photon Counting (PC) mode.
One uncatalogued X-ray source has been detected, it is not above the RASS limit or shows definitive signs of fading. Furthermore, it is coincident with a known optical source and the XRT data are possibly affected by stray light. Therefore we believe that XRT has not detected any viable candidate afterglow. Details of the sources are given below:
Source 3:
```
  RA (J2000.0):  80.9041  =  05:23:36.99
  Dec (J2000.0): -71.0096  =  -71:00:34.6
  Error: 4.1 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: (5.3 [+2.7, -2.0])e-3 ct s^-1   
  Distance: 664 arcsec from Fermi/LAT position.
  Flux: (1.53 [+0.77, -0.59])e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
```
A catalogued source was also detected inside the LAT error circle, and two more sources were detected outside of it.
The 3 sigma upper limit at the LAT GRB position is 7.6�10-3 ct s-1.
The results of the XRT-team automatic analysis of the tiled XRT observations, including a position-specific upper limit calculator, are available at https://www.swift.ac.uk/xrt_products/TILED_GRB00094.
This circular is an official product of the Swift-XRT team.
GCN Circular #28873
S. Gupta, V. Sharma and D. Bhattacharya (IUCAA), V. Bhalerao (IIT-B), A. R. Rao (IUCAA/TIFR) and S. Vadawale (PRL) report on behalf of the AstroSat CZTI collaboration:
The AstroSat CZT Imager recorded a transient event in all four of its CsI anticoincidence (Veto) detectors in the 100-500 keV energy range, coincident with the long GRB 201104A reported by Fermi GBM (GCN #28823), Global MASTER-Net (Lipunov V. et al., GCN #28824), Fermi LAT (Ohno M. et al., GCN #28828), AGILE/MCAL (Ursi A. et al., GCN #28829), Fermi GBM (Bissaldi E. et al., GCN #28830), Tiled Swift (Evans P. et al., GCN #28832), BALROG (Kunzweiler F. et al., GCN #28834) and Swift-XRT (D'Elia V. et al., GCN #28859). There was a weak detection in the main CZT detectors in the 40-200 keV energy range.
The light curve showed multiple peaks of emission with the strongest peak at 2020-11-04 00:00:55.000 UT. The measured peak count rate is 1757 +/- 68 cts/s above the background in the combined Veto data of four quadrants, with a total of 6949 +/- 80 cts. The local mean background count rate was 2774 +/- 5 cts/s. We measure a T90 of 8.18 +/- 0.13 s from the cumulative Veto light curve.
In the main CZT detectors, the light curve showed multiple peaks of emission with the strongest peak at 2020-11-04 00:00:56.000 UT. The measured peak count rate associated with the burst is 330 +/- 33 cts/s above the background in the combined data of four quadrants, with a total of 1170 +/- 23 cts. The local mean background count rate was 792 +/- 2 cts/s. Using cumulative rates, we measure a T90 of 7.36 +/- 0.11 s.
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.

Back to JG's homepage

Jochen Greiner, last update: 09-Nov-2020 [Disclaimer]