Hekatelyne Carpes and Rogemar A. Riffel
Understanding the Emission of OH
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.