Radio interferometric observations of candidate water-maser-emitting planetary nebulae

Abstract

We present Very Large Array (VLA) observations of H2O and OH masers, as well as radio continuum emission at 1.3 and 18 cm toward three sources previously cataloged as planetary nebulae (PNe) and in which single-dish detections of H2O masers have been reported: IRAS 17443-2949, IRAS 17580-3111, and IRAS 18061-2505. Our goal was to unambiguously confirm their nature as water-maser-emitting PNe, a class of objects of which only two bona-fide members were previously known. We detected and mapped H2O maser emission toward all three sources, while OH maser emission is detected in IRAS 17443-2949 and IRAS 17580-3111 as well as in other two objects within the observed fields: IRAS 17442-2942 (unknown nature) and IRAS 17579-3121 (also cataloged as a possible PN). We found radio continuum emission associated only with IRAS 18061-2505. Our results confirm IRAS 18061-2505 as the third known case of a PN associated with H2O maser emission. The three known water-maser-emitting PNe have clear bipolar morphologies, which suggests that water maser emission in these objects is related to non-spherical mass-loss episodes. We speculate that these bipolar PNe would have ``water-fountain'' Asymptotic Giant Branch (AGB) and post-AGB stars as their precursors. A note of caution is given for other objects that have been classified as OHPNe (objects with both OH maser and radio continuum emission, that could be extremely young PNe) based on single-dish observations, since interferometric data of both OH masers and continuum are necessary for a proper identification as members of this class.

arXiv comment33 pages, 10 figures. Accepted by The Astronomical Journal

References in corpus (12)

• A spectroscopic atlas of post-AGB stars and planetary nebulae selected from the IRAS Point Source Catalogue
• H2O Maser Observations of Candidate Post-AGB Stars and Discovery of Three High-velocity Water Sources
• OH-selected AGB and post-AGB objects I.Infrared and maser properties
• The spatio-kinematical structure and distance of the pre-planetary nebula IRAS 19134+2131
• A survey for water maser emission towards planetary nebulae. New detection in IRAS 17347-3139
• OH Maser Observations of Planetary Nebulae Precursors
• New detections of H2O masers in planetary nebulae and post-AGB stars using the Robledo-70m antenna
• Spitzer/IRS spectroscopy of high mass precursors to planetary nebulae
• Water Maser Kinematics in the Jet of OH 12.8-0.9
• A precessing jet model for the PN K 3-35: simulated radio-continuum emission
• Detection of HCO+ Emission toward the Planetary Nebula K 3-35
• Spectral index of the H2O-maser emitting planetary nebula IRAS 17347-3139

Cited by in corpus (15)

• ALMA imaging of the nascent planetary nebula IRAS 15103-5754
• The magnetic field toward the young planetary nebula K~3-35
• An updated catalog of OH-maser-emitting planetary nebulae
• Water maser detections in southern candidates to post-AGB stars and Planetary Nebulae
• Measurement of the Distance and Proper Motions of the H2O Masers in the Young Planetary Nebula K 3-35
• The first "water fountain" collimated outflow in a planetary nebula
• A collimated, ionized bipolar structure and a high density torus in the young planetary nebula IRAS 17347-3139
• Accurate OH maser positions II. the Galactic Center region
• H${}_2$O maser emission associated with the planetary nebula IRAS 16333$-$4807
• Interferometric confirmation of "water fountain" candidates
• A search for water maser emission toward obscured post-AGB star and planetary nebula candidates
• Discrete Source Survey of 6 GHz OH emission from PNe & pPNe and first 6 GHz images of K 3-35
• Searching for nascent planetary nebulae: OHPNe candidates in the SPLASH survey
• Fallback in bipolar Planetary Nebulae ?
• Is the nitrogen-rich source PN K4-47 a true planetary nebula?