Positions of hydroxyl masers at 1665 and 1667 MHz

Robert Hooke's Micrographia of 1665 and 1667.

A Very High Spectral Resolution Study of Ground-state Oh Masers in W3(oh)

We present VLBA observations of the ground-state hydroxyl masers in W3(OH) at 0.02 km s−1 spectral resolution. Over 250 masers are detected, including 56 Zeeman pairs. Lineshapes are predominantly Gaussian or combinations of several Gaussians, with normalized deviations typically of the same magnitude as in masers in other species. Typical FWHM maser linewidths are 0.15 to 0.38 km s−1 and are l...

The Magnetic Field toward the Young Planetary Nebula K 3 - 35

K 3-35 is a planetary nebula (PN) where H2O maser emission has been detected, suggesting that it departed from the proto-PNe phase only some decades ago. Interferometric VLA observations of the OH 18 cm transitions in K 3-35 are presented. OH maser emission is detected in all four ground state lines (1612, 1665, 1667, and 1720 MHz). All the masers appear blueshifted with respect to the systemic...

Phase-Referenced VLBA Observations of OH Masers at 4765 MHz

We report VLBA observations of maser emission from the rotationally excited Π1/2, J = 1/2 state of OH at 4765 MHz. We made phase-referenced observations of W3(OH) at both 4765 MHz and 1720 MHz and found emission in three fields within a ∼2000 AU diameter region and verified that in two of the three fields, 4765 MHz and 1720 MHz emission arise from the same position to within ∼4 mas (∼8 AU). We ...

Ground - state OH observations towards NGC 6334

We have made observations of the four hyperfine transitions of the 2Π3/2, J=3/2 ground state of OH at 1612, 1665, 1667 and 1720 MHz and the related 1.6-GHz continuum emission, towards NGC 6334 using the Australia Telescope Compact Array. The observations covered all the major radio continuum concentrations aligned along the axis of NGC 6334 (V, A to F). We have detected seven OH masers plus a p...