Introduction Gigahertz peaked spectrum (GPS) sources have a sharply peaked radio spectrum and possess one or more compact components that are physically small (!100pc), highly luminous (P ? ... The incidence of extended structure in GPS sources is small, at around 20% of all the objects examined (O'dea et al, 1991, ApJ, 380, 66). ... Absorption Processes It has long been thought that the low frequency spectral turnover characteristic of GPS sources is because of synchrotron self­absorption (SSA). ...

... 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 ...