GeminiFocus July 2018 - Page 7

Hekatelyne Carpes and Rogemar A. Riffel Understanding the Emission of OH Megamaser Galaxies We used multifacility observations of the OH megamaser galaxy IRAS F23199+0123 and found evidence for an active galactic nucleus still immersed in dense layers of dust and gas, as well as gas outflows associated with the maser emission. Studying this class of object is important for understanding the star forming process, black hole growth, and nature of the gas involved in this kind of galaxy environment and investigating possible factors related to OH megamaser formation. In the past, we understood galaxies as isolated and non-interacting systems. However, nowadays, we know that these objects are subject to the environmental effects of other galaxies immediately distributed around them. The increase in the number of galaxy cata- logs has brought with it the realization that galaxies are rarely found alone, and that gal- axy groups are the most common environment in which galaxies are found. The catalogs also provide numerous examples of galaxy interactions with peculiar morphologies. These systems arouse interest in understanding their properties as galaxy interactions play an important role in galaxy formation and evolution. One example of the interaction phenomena that interests us is found among the ultralu- minous infrared galaxies (ULIRGs) — a relatively new class of objects consisting typically of a mixture of galaxy pairs, galaxy interactions, and/or galaxy mergers. The now defunct Infrared Astronomy Satellite (IRAS) — the first ever spacecraft to survey the sky at infrared wavelengths — mapped in 1983 about 96% of the sky and detected about 350,000 infra- red sources; among them were the enigmatic ULIRGs. July 2018 GeminiFocus 5