H[sub 0] from reverberations in an irradiated accretion disc

Abstract

We show how wavelength-dependent time delays observed in AGN variability studies can be used to test the accretion disc model by mapping the disc temperature profile T(R) and determine Hubble’s constant, H0. X-ray reprocessing in a steady-state blackbody accretion disc model with T4∝MṀR−3 incurs a wavelength-dependent light travel time delay τ∝(MṀ)1/3λ4/3. Optical continuum variations in NGC 7469 lag those at 1315 Å by about 1 day at 4800 Å to about 2 days at 7500 Å. The time delays are consistent with a T∝R−3/4 structure. The spectral energy distribution fν∝cos i(H0/z)2(MṀ)2/3λ−1/3 agrees with the dereddened variable component of the UV/optical continuum fluxes if H0(cos i/cos 60°)1/2=60±5 km s−1 Mpc−1.

Related Papers

• → Research on Large-Area Blackbody Radiation Source for Infrared Remote Sensor Calibration(2022)6 cited
• → Exact research on the theory of the blackbody thermal radiation(2016)14 cited
• THE RESEARCH OF UNIFORM TEMPERATURE STRUCTURE FOR LOW TEMPERATURE EXTENDED AREA BLACKBODY(2012)
• → Study on the accuracy of an IR standard radiation source(1994)
• CALIBRATION FOR RADIATION CHARACTERISTIC OF EXTEND BLACKBODY(2002)