Extragalactic maser surveys
  Since the IAU (maser-)Symposium 287 in Stellenbosch/South Africa (Jan. 2012),
great progress has been achieved in studying extragalactic maser sources.
Sensitivity has reached a level allowing for dedicated maser surveys of
extragalactic objects. These included, during the last years, water vapor
(H2O), methanol (CH3OH), and formaldehyde (H2CO), while surveys related to
hydroxyl (OH), cyanoacetylene (HC3N) and ammonia (NH3) may soon become (again)
relevant. Overall, with the upgraded Very Large Array (VLA), the Atacama Large
Millimeter/submillimeter Array (ALMA), FAST (Five hundred meter Aperture
Synthesis Telescope) and the low frequency arrays APERTIF (APERture Tile in
Focus), ASKAP (Australian Square Kilometer Array Pathfinder) and MeerKAT (Meer
Karoo Array Telescope), extragalactic maser studies are expected to flourish
during the upcoming years. The following article provides a brief sketch of
past achievements, ongoing projects and future perspectives.
