... A typical spectrum (such as Figure 1) shows the classic triple-peaked spectrum, which is associated with masers located in a circumnuclear disk (e.g. NGC 4258, Nakai et al., ... The Circinus galaxy megamasers are known to be variable on timescales of weeks and months with individual maser features having a lifetime of around one year. ... Most of the masers observed showed some degree of variability over an hour while one feature displayed a doubling of its flux density over about 10 minutes. ...

... Twenty-Six Year Monitoring of Water Masers IAU Symposium 242, Alice Springs 1 Contents of the work A sample of H2O maser emission sources has been observed since 1980. ... Rudnitskij et al. ... Twenty-Six Year Monitoring of Water Masers IAU Symposium 242, Alice Springs 4 Maser in a protoplanetary disc (S255) Flux density, Jy S255: H2O line profile 5 February 2002 Radial velocity, LSR, km/s Rudnitskij et al. ... Twenty-Six Year Monitoring of Water Masers IAU Symposium 242, Alice Springs 12 ...