GCN Circular 41765

P.A. Evans (U. Leicester), J.A. Kennea (PSU), E. Ambrosi  (INAF-IASFPA) , A.P.
Beardmore (U. Leicester), M.G. Bernardini (INAF-OAB), R. Brivio (INAF-OAB), D.N.
Burrows (PSU), S. Campana (INAF-OAB), M. Capalbi (INAF-OAR), A. D'Ai (INAF-IASFPA),
P. D'Avanzo (INAF-OAB), V. D'Elia (SSDC & INAF-OAR), S. Dichiara (PSU), M. Ferro
(INAF-OAB), A. Melandri (INAF-OAR), J.P. Osborne (U. Leicester), K.L. Page (U.
Leicester), M. Perri (SSDC & INAF-OAR), C. Salvaggio (INAF-OAB), T. Sbarrato
(INAF-OAB), B. Sbarufatti (INAF-OAB), M.A. Williams (PSU) report on behalf of the
Swift-XRT team:

Swift-XRT has performed follow-up observations of the Einstein Probe/WXT-detected
source EP#01709240653, collecting 1.8 ks of Photon Counting (PC) mode data between
T0+859 s and T0+6.8 ks after the trigger. We have detected 2 sources.  These have
been automatically classified as follows:
  * 0 likely counterparts
  * 0 candidate counterparts
  * 2 uncatalogued X-ray sources
  * 0 known X-ray sources

Uncatalogued X-ray sources
--------------------------

  Source 1 (SWIFT J194954.4-572931):
  ==================================
    RA (J2000.0):   297.4769  =  19 49 54.46
    Dec (J2000.0):  -57.4921  =  -57 29 31.6
    Error:	    5.7 (arcsec, radius, 90% confidence).
    Detect flag:    GOOD
    Distance:	    1.6 arcmin from the Einstein Probe/WXT position.
    Mean rate:	    0.0334 [+0.0053, -0.0052] ct s^-1
    Mean flux:	    (8.9 +/- 1.4)e-13 erg cm^-2 s^-1
    Peak rate:	    0.085 +/- 0.025 ct s^-1
    Peak flux:	    (2.25 +/- 0.66)e-12 erg cm^-2 s^-1
    ECF:	    2.65e-11 erg cm^-2 ct^-1
		      assuming NH=4.43e+20 cm^-2, gamma=2.38
		      determined from a spectral fit.
    XMM UL:	    2.1e-12 erg cm^-2 s^-1, (0.3-10 keV)
		      so the source is 0.3-sigma above this 3-sigma upper limit.
    The source may be fading, at the 1.9-sigma level.
    There are 2 2MASS objects within the source's 3-sigma error radius.

  Source 5 (SWIFT J194951.3-573147):
  ==================================
    RA (J2000.0):   297.4638  =  19 49 51.31
    Dec (J2000.0):  -57.5299  =  -57 31 47.6
    Error:	    6.8 (arcsec, radius, 90% confidence).
    Detect flag:    POOR
    Distance:	    1.8 arcmin from the Einstein Probe/WXT position.
    Mean rate:	    (-1.0 +/- -1.0)e0 ct s^-1
    Mean flux:	    (-4.3 +/- -4.3)e-11 erg cm^-2 s^-1
    Peak rate:	    (6.0 [+4.5, -3.2])e-3 ct s^-1
    Peak flux:	    (2.6 [+1.9, -1.4])e-13 erg cm^-2 s^-1
    XMM UL:	    1.9e-12 erg cm^-2 s^-1, (0.3-10 keV)
		      so the source is not above this 3-sigma upper limit.
    There is no evidence for fading.
    There is 1 2MASS object within the source's 3-sigma error radius.

All fluxes are 0.3-10 keV, observed. For all flux conversions and comparisons with
catalogues and upper limits  from other missions, we assumed a power-law spectrum
with NH=3x10^20 cm^-2 and photon index (Gamma)=1.7 unless otherwise stated.

The results of the XRT-team automatic analysis of the XRT observations, including a
position-specific upper limit calculator, are available at
https://www.swift.ac.uk/EP/EP_FIELD00071.

This circular is an official product of the Swift-XRT team.