Discrete Source Survey of 6 GHz OH emission from PNe & pPNe and first 6 GHz images of K 3-35

Abstract

The aim of this study is to investigate the physical properties of molecular envelopes of planetary nebulae in their earliest stages of evolution. Using the 100m telescope at Effelsberg, we have undertaken a high sensitivity discrete source survey for the first excited state of OH maser emission (J=5/2, 2PI3/2 at 6GHz) in the direction of planetary and proto-planetary nebulae exhibiting 18cm OH emission (main and/or satellite lines), and we further validate our detections using the Nançay radio telescope at 1.6-1.7GHz and MERLIN interferometer at 1.6-1.7 and 6GHz. Two sources have been detected at 6035MHz (5cm), both of them are young (or very young) planetary nebulae. The first one is a confirmation of the detection of a weak 6035MHz line in Vy 2-2. The second one is a new detection, in K 3-35, which was already known to be an exceptional late type star because it exhibits 1720MHz OH emission. The detection of 6035MHz OH maser emission is confirmed by subsequent observations made with the MERLIN interferometer. These lines are very rarely found in evolved stars. The 1612MHz masers surround but are offset from the 1720 and 6035MHz masers which in turn lie close to a compact 22GHz continuum source embedded in the optical nebula.

9 pages, 7 figures, published in A&A

References in corpus (9)

• A Survey of OH Masers Towards High Mass Protostellar Objects
• Kinematics of the H2O masers at the centre of the PN K3-35
• Radio interferometric observations of candidate water-maser-emitting planetary nebulae
• The magnetic field toward the young planetary nebula K~3-35
• Evolution of 1612 MHz Maser Emission in Expanding Circumstellar Shells
• A MERLIN Study of 6 GHz Excited-state OH & 6.7 GHz Methanol Masers in ON1
• A precessing jet model for the PN K 3-35: simulated radio-continuum emission
• Search for radiative pumping lines of OH masers: I. The 34.6um absorption line towards 1612 MHz OH maser sources
• Excited-state OH Mainline Masers in AU Geminorum and NML Cygni

Cited by in corpus (6)

• Confirmation of the exclusive association between 6.7-GHz methanol masers and high-mass star formation regions
• Excited-state hydroxyl maser catalogue from the methanol multibeam survey -- I. Positions and Variability
• An updated catalog of OH-maser-emitting planetary nebulae
• Unusual shock-excited OH maser emission in a young Planetary Nebula
• Polarization properties of OH emission in planetary nebulae
• Detection of 4765 MHz OH Emission in a Pre-Planetary Nebula -- CRL 618