Abstract
We study the 0.5-10 keV emission of a sample of five of the broadest double-peaked Balmer line emitters with Chandra. The Balmer lines of these objects originate close (within a few hundred gravitational radii) to the central black holes of the active galactic nuclei (AGNs), and their double-peaked profiles suggest an origin in the AGN accretion disk. We find that four of the five targets can be modeled by simple power-law continua with photon indices (1.6 ⩽ Γ ⩽ 1.8) typical of similar luminosity AGNs. One object, SDSS J0132–0952, shows evidence of ionized intrinsic absorption. The most luminous SDSS double-peaked emitter, SDSS J2125–0813, has either an unusual flat spectrum (Γ ∼ 1) or is also highly absorbed. It is the only double-peaked emitter for which no external illumination is necessary to account for the Balmer line emission. The strength of the Balmer line emission in the remaining four objects suggests that the total line flux likely exceeds the viscous energy that can be extracted locally from the accretion disk and external illumination is necessary. All five double-peaked emitters have unusually strong X-ray emission relative to their UV/optical emission, which is the likely source of the external illumination necessary for the production of the observed strong broad lines. On average about 30% of their bolometric luminosities are emitted between 0.5 and 10 keV. The spectral energy distributions of the five double-peaked emitters show the big blue bumps characteristic of radiatively efficient accretion flows. The Balmer line profiles, as well as the optical and X-ray fluxes of the double-peaked emitters, are highly variable on timescales of months to years in the AGN rest frame.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.