GCN Circular 21930
Subject
IceCube-170922A: Swift-XRT observations
Date
2017-09-26T14:34:30Z (7 years ago)
From
Azadeh Keivani at PSU <keivani@psu.edu>
A. Keivani (PSU), P.A. Evans (U. Leicester), J.A. Kennea (PSU), D.B. Fox
(PSU), D.F. Cowen (PSU), J.P. Osborne (U. Leicester), and F.E.
Marshall (GSFC) report on behalf of the Swift-IceCube collaboration:
Swift has observed the field of the IceCube EHE event, IceCube-170922A
(revision 0, https://gcn.gsfc.nasa.gov/notices_amon/50579430_130033.amon),
utilizing the on-board 19-point tiling pattern to cover a region
centred on RA,Dec (J2000) = (77.2866d, +5.7537d), with a radius of
approximately 0.8 degrees. Swift-XRT collected ~800 s per field of PC
mode data per tile. The observations were taken between 00:09:16 UT
and 22:42:08 UT on 2017 September 23 (i.e. from 11.7 ks to 92.9 ks
after the neutrino trigger), and covered 2.1 square degrees.
Nine X-ray sources are detected in the observations. Eight of these
correspond to known X-ray emitters. One object (Source 6) is not
catalogued in X-rays, however it lies 5.7" from PMN J0511+0538 which
is a radio source. The X-ray source position is RA,Dec (J2000) =
(77.8658d, +5.6420d) which is equivalent to:
RA = 05h 11m 27.80s
Dec = +05d 38' 31.2"
with an uncertainty of 7.1" [90% confidence radius]. The mean XRT
count rate is 6.9 (+3.7, -2.8) e-3 ct s^-1. More XRT follow-up
observations have been requested.
The 3-sigma upper limit on the count rate in the rest of the field is
0.0093 ct s^-1, which corresponds to a 0.3-10 keV flux of 3.8e-13 erg
cm^-2 s^-1 for a typical AGN spectrum (NH=3e20 cm^-2, Gamma=1.7).
Overlaps between the different tiles account for 0.5 square degrees:
in these regions the 3-sigma upper limit is 0.0057 ct s^-1,
corresponding to 2.3e-13 erg cm^-2 s^-1.
Source 1:
=============
RA: 76.7226 ( = 05h 06m 53.42s) J2000
Dec: +6.1154 ( = +06d 06' 55.4") J2000
Error: +4.3 (arcsec, radius, 90% confidence).
Peak Rate: 5.6e-02 +/- 1.4e-02 ct/sec (0.3-10 keV)
Peak Flux: 2.3e-12 +/- 5.7e-13 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1RXS J050653.3+060648 in the ROSAT/RASSBSC catalogue
Separation: 7.6" from the XRT source
Cat Rate: 1.2e-01 +/- 2.0e-02 ct/sec
Cat Flux: 1.8e-12 +/- 3.0e-13 erg cm^-2 s^-1 (0.3-10 keV)
A SIMBAD object `TYC 110-755-1' is 3.6" away.
Source 2:
=============
RA: 77.3571 ( = 05h 09m 25.70s) J2000
Dec: +5.6924 ( = +05d 41' 32.6") J2000
Error: +4.2 (arcsec, radius, 90% confidence).
Peak Rate: 9.3e-02 +/- 2.1e-02 ct/sec (0.3-10 keV)
Peak Flux: 3.8e-12 +/- 8.6e-13 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1SXPS J050925.9+054134 in the 1SXPS catalogue
Separation: 4.7" from the XRT source
Cat Rate: 3.9e-02 +/- 2.6e-03 ct/sec
Cat Flux: 1.7e-12 +/- 1.1e-13 erg cm^-2 s^-1 (0.3-10 keV)
A SIMBAD object `QSO J0509+0541' is 4.8" away.
Source 3:
=============
RA: 77.6614 ( = 05h 10m 38.74s) J2000
Dec: +5.9082 ( = +05d 54' 29.5") J2000
Error: +5.1 (arcsec, radius, 90% confidence).
Peak Rate: 1.5e-02 +/- 4.1e-03 ct/sec (0.3-10 keV)
Peak Flux: 6.2e-13 +/- 1.7e-13 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1RXS J051038.6+055432 in the ROSAT/RASSBSC catalogue
Separation: 3.8" from the XRT source
Cat Rate: 5.9e-02 +/- 1.4e-02 ct/sec
Cat Flux: 1.7e-12 +/- 4.0e-13 erg cm^-2 s^-1 (0.3-10 keV)
A SIMBAD object `2MASS J05103912+0554261' is 6.7" away.
Source 4:
=============
RA: 77.1391 ( = 05h 08m 33.38s) J2000
Dec: +5.5188 ( = +05d 31' 07.7") J2000
Error: +5.5 (arcsec, radius, 90% confidence).
Peak Rate: 1.7e-01 +/- 1.3e-01 ct/sec (0.3-10 keV)
Peak Flux: 7.0e-12 +/- 5.3e-12 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: XMMSL2 J050833.1+053121 in the XMM-NEWTON/XMMSLEWCLN catalogue
Separation: 13.5" from the XRT source
Cat Rate: 6.9e-01 +/- 2.9e-01 ct/sec
Cat Flux: 6.1e-12 +/- 2.6e-12 erg cm^-2 s^-1 (0.3-10 keV)
Source 5:
=============
RA: 77.4264 ( = 05h 09m 42.34s) J2000
Dec: +5.7826 ( = +05d 46' 57.4") J2000
Error: +5.3 (arcsec, radius, 90% confidence).
Peak Rate: 1.7e-02 +/- 6.4e-03 ct/sec (0.3-10 keV)
Peak Flux: 7.0e-13 +/- 2.6e-13 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1SXPS J050942.4+054655 in the 1SXPS catalogue
Separation: 2.0" from the XRT source
Cat Rate: 7.2e-03 +/- 1.2e-03 ct/sec
Cat Flux: 3.1e-13 +/- 5.2e-14 erg cm^-2 s^-1 (0.3-10 keV)
A SIMBAD object `HD 33326' is 2.1" away.
Source 7:
=============
RA: 77.1531 ( = 05h 08m 36.74s) J2000
Dec: +5.2053 ( = +05d 12' 19.1") J2000
Error: +6.0 (arcsec, radius, 90% confidence).
Peak Rate: 2.5e-02 +/- 7.0e-03 ct/sec (0.3-10 keV)
Peak Flux: 1.0e-12 +/- 2.9e-13 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: XMMSL2 J050836.8+051224 in the XMM-NEWTON/XMMSLEWCLN catalogue
Separation: 4.7" from the XRT source
Cat Rate: 9.5e-01 +/- 4.1e-01 ct/sec
Cat Flux: 9.5e-12 +/- 4.1e-12 erg cm^-2 s^-1 (0.3-10 keV)
A SIMBAD object `V* V1848 Ori' is 5.8" away.
Source 8:
=============
RA: 77.2410 ( = 05h 08m 57.84s) J2000
Dec: +6.4408 ( = +06d 26' 26.9") J2000
Error: +5.9 (arcsec, radius, 90% confidence).
Peak Rate: 3.0e-02 +/- 8.1e-03 ct/sec (0.3-10 keV)
Peak Flux: 1.2e-12 +/- 3.3e-13 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1RXS J050857.4+062633 in the ROSAT/RASSBSC catalogue
Separation: 9.3" from the XRT source
Cat Rate: 1.2e-01 +/- 1.8e-02 ct/sec
Cat Flux: 2.5e-12 +/- 3.9e-13 erg cm^-2 s^-1 (0.3-10 keV)
A SIMBAD object `1RXS J050857.4+062633' is 7.9" away.
Source 9:
=============
RA: 77.4368 ( = 05h 09m 44.83s) J2000
Dec: +5.3639 ( = +05d 21' 50.0") J2000
Error: +5.7 (arcsec, radius, 90% confidence).
Peak Rate: 1.4e-02 +/- 5.0e-03 ct/sec (0.3-10 keV)
Peak Flux: 5.7e-13 +/- 2.0e-13 erg cm^-2 s^-1 (0.3-10 keV)
Cat Source: 1RXS J050944.9+052219 in the ROSAT/RASSFSC catalogue
Separation: 28.9" from the XRT source
Cat Rate: 2.1e-02 +/- 9.5e-03 ct/sec
Cat Flux: 2.3e-13 +/- 1.1e-13 erg cm^-2 s^-1 (0.3-10 keV)