Extragalactic H_2O Megamaser Sources:Central Black Holes,Nuclear X-ray and Maser Emissions

摘要

Extragalactic H2O megamasers are typically found within the innermost few parsecs of active galaxy nuclei(AGN) and the maser emission is considered to be excited most likely by the X-ray irradiation of the AGN.We investigate a comprehensive sample of extragalactic H2O masers in a sample of 38 maser host AGN to check potential correlations of the megamaser emission with parameters of the AGN,such as X-ray luminosity and black hole(BH) masses.We find a relation between the maser luminosities and BH masses,LH2O ∝ M B3.H6± 0.4,which supports basically the theoretical prediction.The relation between the maser emission and X-ray emission is also confirmed.