X-ray follow-up of 3C120 activity
ATel #6606; Anne Lohfink (IoA, Cambridge), Ashley L. King (IoA, Cambridge), Chris Reynolds (UMCP), Andy Fabian (IoA, Cambridge)
on 22 Oct 2014; 14:19 UT
Credential Certification: Anne Lohfink (alohfink@ast.cam.ac.uk)
Subjects: Radio, Optical, Ultra-Violet, X-ray, Gamma Ray, AGN, Black Hole, Quasar
Referred to by ATel #: 6613
We report on the Swift follow-up observations to the observed gamma-ray flaring of the broad-line radio galaxy 3C120 as presented in ATEL #6529 and ATEL #6542. Three observations were taken on 10/4/2014, 10/7/2014 and 10/8/2014. During these observations the source was found to be rather bright with an observed X-ray flux of about 6E-11 ergs/s/cm^2 in the 0.5-6 keV band. The V-band fluxes in a 5 arcsec aperture were found to be (6.35+/-0.25)x10^-15 ergs/s/cm^2/A, (6.24+/-0.18)x10^-15 ergs/s/cm^2/A, and (6.12+/-0.20)x10^-15 ergs/s/cm^2/A. The W2 band fluxes do not show a similar decrease to the V-band fluxes but are (7.99+/-0.15)x10^-15 ergs/s/cm^2/A, (8.67+/-0.21)x10^-15 ergs/s/cm^2/A and (8.09+/-0.22)x10^-15 ergs/s/cm^2/A. Above 1 keV, the X-ray spectra of the three epochs are all consistent with a power-law of 1.83+/-0.05, which is typical of radio galaxies like 3C 120. Below 1 keV however the spectrum breaks into a very steep power law-like component with a photon index of 3.08+/-0.29. This very soft component could be associated with jet-related emission leaking into the X-ray spectrum. Further observations at longer wavelengths are encouraged to track the propagation of the flare.
