A new jet/outflow maser in the nucleus of the Compton-thick AGN IRAS 15480-0344

• Published in: Proceedings of the International Astronomical Union 2017-09, Vol.13 (S336), p.129-132
• Main Authors: Castangia, Paola, Tarchi, Andrea, Caccianiga, Alessandro, Severgnini, Paola, Surcis, Gabriele, Ceca, Roberto Della
• Format: Article
• Language: English
• Subjects: Contributed Papers
• ISSN: 1743-9213; 1743-9221
• DOI: 10.1017/S1743921317010596

Investigations of H2O maser galaxies at X-ray energies reveal that most harbor highly absorbed AGN. Possible correlations between the intrinsic X-ray luminosity and the properties of water maser emission have been suggested. With the aim of looking into these correlations on a more solid statistical basis, we have search for maser emission in a well-defined sample of Compton-thick AGN. Here we report the results of the survey, which yielded a surprisingly high maser detection rate, with a particular focus on the newly discovered luminous water maser in the lenticular (field) S0 galaxy IRAS 15480-0344. Recently, VLBI observations have been obtained to image the line and continuum emission in the nucleus of this galaxy. The radio continuum emission at VLBI scales is resolved into two compact components that are interpreted as jet knots. Based on the single-dish profile, the variability of the maser emission, and the position of the maser spots with respect to these continuum sources, we favor of a jet/outflow origin for the maser emission, consistent with similar cases found in other radio-quiet AGN. This scenario is consistent with the hypothesis of the presence of strong nuclear winds recently invoked to explain the main characteristics of field S0 galaxies.