GCN Circular 23935

A. D'Ai (INAF-IASFPA), A. Melandri (INAF-OAB), J.A. Kennea (PSU), B.
Sbarufatti (INAF-OAB/PSU), D.N. Burrows (PSU), A.P. Beardmore (U.
Leicester), J.P. Osborne (U. Leicester), P. D'Avanzo (INAF-OAB) and
P.A. Evans (U. Leicester) report on behalf of the Swift-XRT team:

Swift-XRT has performed follow-up observations of the AGILE and MAXI
detected burst GRB 190305A (Ursi et al. GCN Circ. 23930
Not found
 
 
, Nakahira et
al. GCN Circ.23933
Not found
 
 
) in a series of observations tiled on the sky. The
total exposure time is 4.4 ks, distributed over 7 tiles; the maximum
exposure at a single sky location was 1.4 ks. The data were collected
between T0+31.9 ks and T0+43.5 ks, and are entirely in Photon Counting
(PC) mode. 

Six uncatalogued X-ray sources have been detected.  Source 1 is
significantly brighter than the other candidates and  it is marginally
above the RASS limit, although,  at the moment, we cannot assess if it
is fading.

Details of these sources are given below:

Source 1:
  RA (J2000.0):  11.62657  =  00:46:30.38
  Dec (J2000.0): -50.34865  =  -50:20:55.1
  Error: 2.5 arcsec (radius, 90% conf. [Enhanced position])
  Count-rate: 0.100 +/- 0.014 ct s^-1	
  Distance: 1069 arcsec from MAXI position.
  Flux: (4.79 +/- 0.67)e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 2:
  RA (J2000.0):  10.5180  =  00:42:4.32
  Dec (J2000.0): -50.1058  =  -50:06:20.9
  Error: 6.9 arcsec (radius, 90% conf.)
  Count-rate: 0.0109 [+0.0066, -0.0047] ct s^-1   
  Distance: 1875 arcsec from MAXI position.

Source 3:
  RA (J2000.0):  11.5149  =  00:46:3.57
  Dec (J2000.0): -49.9843  =  -49:59:03.4
  Error: 6.5 arcsec (radius, 90% conf.)
  Count-rate: 0.0172 [+0.0055, -0.0045] ct s^-1   
  Distance: 649 arcsec from MAXI position.
  Flux: (1.07 [+0.34, -0.28])e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV)


Source 4:
  RA (J2000.0):  10.8580  =  00:43:25.92
  Dec (J2000.0): -50.1848  =  -50:11:05.2
  Error: 7.7 arcsec (radius, 90% conf.)
  Count-rate: 0.0208 [+0.0085, -0.0067] ct s^-1   
  Distance: 1113 arcsec from MAXI position.
  Flux: (7.6 [+3.1, -2.5])e-12 erg cm^-2 s^-1 (observed, 0.3-10 keV)

Source 5:
  RA (J2000.0):  11.1918  =  00:44:46.04
  Dec (J2000.0): -49.9995  =  -49:59:58.1
  Error: 9.8 arcsec (radius, 90% conf.)
  Count-rate: (5.5 [+4.0, -2.7])e-3 ct s^-1   
  Distance: 538 arcsec from MAXI position.

Source 6:
  RA (J2000.0):  10.7329  =  00:42:55.89
  Dec (J2000.0): -49.9464  =  -49:56:47.0
  Error: 12.4 arcsec (radius, 90% conf.)
  Count-rate: (9.5 [+5.8, -4.2])e-3 ct s^-1   
  Distance: 1515 arcsec from MAXI position.

The results of the XRT-team automatic analysis of the tiled XRT
observations, including a position-specific upper limit calculator, are
available at http://www.swift.ac.uk/xrt_products/TILED_GRB00077.

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