[vsnet-grb-info 26821] IceCube 201114A: Swift followup of Fermi J0703.5+0505

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  28924
SUBJECT: IceCube 201114A: Swift followup of Fermi J0703.5+0505
DATE:    20/11/19 14:28:48 GMT
FROM:    Timothee Gregoire at Penn State  <tmg5746 at psu.edu>

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

Swift has observed the region of Fermi J0703.5+0505 (Garrappa et al., GCN Circ. 28918), a possible counterpart to
IceCube 201114A, gathering 3.6 ks of cleaned PC mode data between 05:32 UT and 21:20 UT on 2020 November 18.

We find 2 sources in this image; the first is coincident with the 7th magnitude K0 star HD 53113 (according to
SIMBAD) and is not an X-ray source at all, but the result of optical loading from this bright object
(see https://www.swift.ac.uk/analysis/xrt/optical_loading.php).

The second source is at RA, Dec = 105.7125, +5.0311 (degrees) which corresponds to:

RA (J2000):  07h 02m 51.00s
Dec (J2000): +05d 01’ 51.8”

With an uncertainty of 4.4 arcsec (radius, 90% confidence). This position is 11.2 arcmin from the LAT position,
within the 99% contour. This source corresponds to the position of 2MASS J07024956+0500399, which SIMBAD
classifies as an RGB star. There is no known X-ray source at this position, however the RASS 3-sigma upper limit is
the equivalent of 0.017 XRT count/s (0.3-10 keV), whereas the observed count rate is significantly below this, at
(5.9 +/- 1.9, -1.6) x10^-3  ct/sec. The source shows no signs of variability, thus we cannot identify it as a new,
outbursting or fading source.

Given this, we do not believe we have found an X-ray counterpart to Fermi J0703.5+0505 or IceCube 201114A.

The 3-sigma upper limit inside the 68% confidence LAT error circle is ~3.2 x 10^-3 ct/sec (0.3-10 keV). Assuming a
power-law spectrum with nH=3 x 10^20 cm^-2 and Gamma=1.7, this corresponds to a 0.3-10 keV flux upper limit of
1.4 x 10^-13 erg cm^-2 s^-1.