A possible discovery of AGN during a NuSTAR calibration observation
ATel #15171; Aysegul Tumer (The University of Utah), Daniel R. Wik (The University of Utah), Kristin K. Madsen (NASA Goddard Space Flight Center, University of Maryland), Francesco Tombesi (University of Rome Tor Vergata), E. Nihal Ercan (Bogazici University)
on 20 Jan 2022; 02:02 UT
Credential Certification: Aysegul Tumer (aysegultumer@gmail.com)
During the analysis of a calibration observation (ObsID:10610035001) of The Nuclear Spectroscopic Telescope Array (NuSTAR; Harrison et al. 2013, ApJ, 770, 103) that took place on 25 April 2020 (JDM 58964), we discovered an AGN candidate. The NuSTAR J2000 coordinates of this source are (RA,Dec) = (05:34:49.20, +21:26:02.9), which will be referred to as NuSTAR J053449+2126.0 or Tumer 1.
The redshift of Tumer 1 is unknown to the best of our knowledge. We extracted a 1 arcmin NuSTAR spectrum centered on the object and fitted a power-law in the 3.0-20.0 keV energy band. The resulting photon index and norm with 1 sigma errors are: Gamma = 2.46 (-0.16,+0.17) and norm = 4.31E-04 (-1.12E-04,+1.53E-04) with cstat/dof = 140.87/149. The flux in the 3.0-10.0 keV energy band is 4.2451E-13 ergs/cm^2/s.
Assuming the source is at z=0.1, the 0.5-2.5 luminosity is L_X = 4.69E+42 erg/s. Assuming a Galactic origin, with a distance of 1 kpc that corresponds to z=2.36900E-07, we found 0.5-2.5 luminosity, L_X = 2.82E+31 erg/s. The redshift of the object is needed to obtain the true luminosity.
We thank the NuSTAR Operations, Software and Calibration teams for scheduling and the execution of these observations. Optical follow up observations are encouraged to find the redshift of the object for luminosity calculations.
