Letter to the Editor

A general relativistic estimation of the black hole mass-to-distance ratio at the core of TXS 2226–184

¹ Instituto de Física Luis Rivera Terrazas, Benemérita Universidad Autónoma de Puebla, CP 72570 Puebla, Mexico
e-mail: aherrera@ifuap.buap.mx
² Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C–3, Ciudad Universitaria, CP 58040 Morelia, Michoacán, Mexico

Received: 28 March 2022
Accepted: 7 June 2022

Abstract

In this work we make use of a general relativistic method to estimate the mass-to-distance ratio M/D = 3.54_−0.18^+0.20 × 10⁴ M_⊙ Mpc⁻¹ of the black hole hosted at the core of the active galactic nucleus of TXS 2226–184, along with its right ascension offset and the recession redshift (velocity) of the galaxy. Our statistical fit is based on the frequency shift of photons emitted by water masers and their orbital positions when circularly revolving around the black hole center within the accretion disk of the active galactic nucleus. By taking a previously reported distance to the galaxy into account, we compare the result of the black hole mass fit to an estimate based on a mass-luminosity correlation. We find that the black hole mass at the core of TXS 2226–184 obtained with the aid of the statistical fit using the general relativistic method, M = 3.67_−0.18^+0.20 × 10⁶ M_⊙, is approximately 0.6 times the black hole mass, M_BH = 6.24_−2.27^+3.63 × 10⁶ M_⊙, which was computed with the mass–luminosity correlation.