A systematic observational study of radio properties of H2O megamaser Seyfert-2 galaxies

• Main Authors: Liu, Z. W, Zhang, J. S, Henkel, C, Liu, J, Müller, P, Guo, J. Z. Wang Q, Wang, J, Li, J
• Format: Journal Article
• Language: English
• Published: 16-12-2016
• Subjects: Physics - Astrophysics of Galaxies
• DOI: 10.48550/arxiv.1612.05315

A systematic study is performed on radio properties of H$_{2}$O megamaser
host Seyfert 2 galaxies, through multi-band radio continuum observations (at
11cm, 6.0 cm, 3.6 cm, 2.0 cm and 1.3 cm) with the Effelsberg 100-m radio
telescope within a total time duration of four days. For comparison, a control
Seyfert 2 galaxy sample without detected maser emission was also observed.
Spectral indices were determined for those sources for which measurements exist
at two adjacent bands assuming a power-law dependence S$_\nu \propto
\nu^{-\alpha}$, where S is the flux density and $\nu$ is the frequency.
Comparisons of the radio continuum properties between megamaser and non-masing
Seyfert 2s show no difference in spectral indices. However, a difference in
radio luminosity is statistically significant, i.e. the maser galaxies tend to
have higher radio luminosities by a factor of 2 to 3 than the non-masing ones,
commonly reaching values above a critical threshold of 10$^{29}$
ergs$^{-1}$Hz$^{-1}$. This result confirms an earlier conclusion by Zhang et
al. (2012), but is based on superior data with respect to the time interval
within which the data were obtained, with respect to the observational facility
(only one telescope used), the number of frequency bands.