TITLE:   GCN CIRCULAR
NUMBER:  29480
SUBJECT: Swift-XRT observations of IceCube-210210A
DATE:    21/02/11 16:37:49 GMT
FROM:    Timothee Gregoire at Penn State  <tmg5746@psu.edu>

A. Keivani (Columbia U.), J.P. Osborne (U. Leicester), F. Krauss (PSU),
T. Gregoire (PSU), P.A. Evans (U. Leicester), J.A. Kennea (PSU),
H. A. Ayala Solares (PSU), D.F. Cowen (PSU), J. DeLaunay (PSU) and D. B. Fox (PSU) report:

Swift observed the field of IceCube 210210A (GCN Circ. 29454) between 14:14:46 on February 10, 2021
and 00:03:08 on February 11, 2021. Due to a technical problem only two pointings were done with a
radius of 0.2 degrees each, one centered on the event position and one centered on 4FGL J1342.7+0505.
A total of 7.5 ks of cleaned photon counting (PC) mode data was collected.

We found 6 X-ray sources, as detailed below. These sources are either known or unknown but with
count rate consistent with the previous non-detections. We therefore do not
claim any of them as the likely counterpart to IceCube 210210A.

Source 5 is coincident with the best position of the assumed optical counterpart to 4FGL J1342.7+0505 reported by SIMBAD. Its count-rate in our follow up data is 2.6 (+/-0.3) x 10^-2 ct s^-1. This source has previously been observed by Swift on 2009 August 29 and is in the 2SXPS catalogue (2SXPS J134243.1+050425) with a count-rate of 2.5 (+/-1.1) x 10^-2 ct s^-1. This is consitent with our new measurement.

The 3-sigma upper limit in the field was in the range 2-3 x 10^-3 ct/sec.

The detected sources were:

Source no:   1
RA (J2000):  206.11779 [degrees] = 13h 44m 28.27s
Dec (J2000): +4.8410 [degrees] = +04d 50' 27.7"
Error:       +2.8 [arcsec, 90% conf. radius]
Count rate (0.3-10 keV): 1.4 (+0.3, -0.3) x 10^-2 ct s-1
Flux (0.3-10 keV):       5.8 (+1.2, -1.1) x 10^-13 erg cm-2 s-1
Note: This is 6" from the SIMBAD object 1RXS J134428.3+045027

Source no:   2
RA (J2000):  206.07773 [degrees] = 13h 44m 18.65s
Dec (J2000): +4.7588 [degrees] = +04d 45' 31.5"
Error:       +4.7 [arcsec, 90% conf. radius]
Count rate (0.3-10 keV): 3.6 (+1.3, -1.1) x 10^-3 ct s-1
Flux (0.3-10 keV):       1.5 (+0.6, -0.5) x 10^-13 erg cm-2 s-1

Source no:   3
RA (J2000):  205.52674 [degrees] = 13h 42m 06.42s
Dec (J2000): +5.0902 [degrees] = +05d 05' 24.6"
Error:       +3.7 [arcsec, 90% conf. radius]
Count rate (0.3-10 keV): 2.3 (+/-0.3) x 10^-2 ct s-1
Flux (0.3-10 keV):       9.7 (+1.4, -1.3) x 10^-13 erg cm-2 s-1
Note: This is 2.4" from the SIMBAD object 2E 3124

Source no:   4
RA (J2000):  205.55271 [degrees] = 13h 42m 12.65s
Dec (J2000): +5.1739 [degrees] = +05d 10' 26.1"
Error:       +6.1 [arcsec, 90% conf. radius]
Count rate (0.3-10 keV): 2.3 (+1.3, -1.0) x 10^-3 ct s-1
Flux (0.3-10 keV):       1.0 (+0.5, -0.4) x 10^-13 erg cm-2 s-1

Source no:   5
RA (J2000):  205.68170 [degrees] = 13h 42m 43.61s
Dec (J2000): +5.0754 [degrees] = +05d 04' 31.3"
Error:       +2.5 [arcsec, 90% conf. radius]
Count rate (0.3-10 keV): 2.6 (+/-0.3) x 10^-2 ct s-1
Flux (0.3-10 keV):       1.11 (+0.15, -0.14) x 10^-12 erg cm-2 s-1

Source no:   6
RA (J2000):  205.74168 [degrees] = 13h 42m 58.00s
Dec (J2000): +5.0609 [degrees] = +05d 03' 39.4"
Error:       +7.6 [arcsec, 90% conf. radius]
Count rate (0.3-10 keV): 2.8 (+1.3, -1.0) x 10^-3 ct s-1
Flux (0.3-10 keV):       1.2 (+0.5, -0.4) x 10^-13 erg cm-2 s-1
Note: This is 2.9" from the SIMBAD object BD+05 2790.