We report the results of a search for 22GHz water maser emission in IRAS-bright galaxies, using the 100-m Effelsberg telescope. In particular, we present the details of four new maser detections (IC 342, NGC 2146, NGC 3556, and Arp 299) and follow-up interferometric studies. A comparison between water maser detection rates derived in the present study and those in previous similar surveys is al...

A sample of J–type carbon stars was searched for OH maser emission. The new detection of three OH lines towards two silicate carbon stars is reported. In V778Cyg, previously known as the main–lines (1665 and 1667MHz) maser source, the satellite 1612MHz emission was discovered while in NSV2814 the main OH lines were detected. The presence of OH maser lines confirms the former suggestion that oxy...

Content. Electron-cyclotron maser emission (ECME) is the favored mechanism for solar radio spikes and has been investigated extensively since 1980s. Most studies relevant to employ a loss-cone-type distribution of energetic electrons, generating waves mainly in fundamental X/O mode (X1/O1), with ratio plasma oscillation frequency electron gyrofrequency (${\omega}_ {pe}/{\Omega}_{ce}$) lower tha...

High-resolution VLA observations of 1720 MHz OH maser emission from Sgr A East and the circumnuclear disk with spatial and spectral resolutions of ≈ 2. ′′ 5 × 1. ′′ 3 and 0.27 kms −1 are reported. This follow-up observational study focuses on the recent discovery of a number of such OH maser features and their intense circularly polarized maser lines detected toward these Galactic center source...

W75N is a star-forming region containing various ultracompact HII regions and OH, H 2 O, and CH 3 OH maser emission. Our VLBA map shows that the OH masers are located in a thin disk rotating around an O-star which is the exciting star of the ultracompact HII region VLA1. A separate set of maser spots is connected with the ultracompact HII region VLA2. The radial velocity of OH maser spots varie...

We report the operation of a Rb maser in the self-oscillating mode, using a laser diode as the optical pumping source. The maser uses a TE021 cavity surrounding a cell containing the atoms and 11 Torr of N2 as the buffer gas. The optical pumping is accomplished by using a commercial laser diode frequency-locked on the linear absorption line of an external rubidium cell. The maser output power ∗...

MERLIN images of Mrk 348 at 22 GHz show H 2 O maser emission at 0.02 – 0.11 Jy, within ∼ 0.8 pc of the nucleus. This is the first direct confirmation that molecular material exists close to the Seyfert 2 nucleus. Mrk 348 was observed in 2000 May one month after Falcke et al. (2000) first identified the maser in single-dish spectra. The peak maser flux density has increased about threefold. The ...

Context. The high intensities and narrow bandwidths exhibited by some astronomical masers make them ideal tools for studying star-forming giant molecular clouds. The water maser transition JK−1K1 = 532−441 at 620.701 GHz can only be observed from above Earth’s strongly absorbing atmosphere; its emission has recently been detected from space. Aims. We sought to further characterize the star-form...