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We report on OH maser emission toward G336.644−0.695 (IRAS 16333−4807), which is a H₂O maser-emitting Planetary Nebula (PN). We have detected 1612, 1667, and 1720 MHz OH masers at two epochs using the Australia Telescope Compact Array, hereby confirming it as the seventh known case of an OH-maser-emitting PN. This is only the second known PN showing 1720 MHz OH masers after K 3−35 and the only evolved stellar object with 1720 MHz OH masers as the strongest transition. This PN is one of a group of very young PNe. The 1612 MHz and 1667 MHz masers are at a similar velocity to the 22 GHz H₂O masers, whereas the 1720 MHz masers show a variable spectrum, with several components spread over a higher velocity range (up to 36 km s⁻¹). We also detect Zeeman splitting in the 1720 MHz transition at two epochs (with field strengths of ~2 to ~10 mG), which suggests the OH emission at 1720 MHz is formed in a magnetized environment. These 1720 MHz OH masers may trace short-lived equatorial ejections during the formation of the PN.

Item Type:	Refereed Article
Keywords:	masers, planetary nebulae: general, planetary nebulae: individual (IRAS 16333–4807)
Research Division:	Physical Sciences
Research Group:	Astronomical and Space Sciences
Research Field:	Galactic Astronomy
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Physical Sciences
Author:	Ellingsen, SP (Professor Simon Ellingsen)
ID Code:	107757
Year Published:	2016
Deposited By:	Mathematics and Physics
Deposited On:	2016-03-23
Last Modified:	2017-11-03
Downloads:	133 View Download Statistics