IceCube 201114A: Swift followup of Fermi J0703.5+0505
Abstract
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.
- Publication:
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GRB Coordinates Network
- Pub Date:
- November 2020
- Bibcode:
- 2020GCN.28924....1D