We present observations of continuum ( \lambda = 0.7 , 1.3 , 3.6 and 18 cm ) and OH maser ( \lambda = 18 cm ) emission toward the young planetary nebula IRAS 17347 - 3139 , which is one of the three planetary nebulae that are known to harbor water maser emission .
From the continuum observations we show that the ionized shell of IRAS 17347 - 3139 consists of two main structures : one extended ( size \sim 1 \hbox to 0.0 pt { . } ^ { \prime \prime } 5 ) with bipolar morphology along PA= - 30 ^ { \circ } , elongated in the same direction as the lobes observed in the near-infrared images , and a central compact structure ( size \sim 0 \hbox to 0.0 pt { . } ^ { \prime \prime } 25 ) elongated in the direction perpendicular to the bipolar axis , coinciding with the equatorial dark lane observed in the near-infrared images .
Our image at 1.3 cm suggests the presence of dense walls in the ionized bipolar lobes .
We estimate for the central compact structure a value of the electron density at least \sim 5 times higher than in the lobes .
A high resolution image of this structure at 0.7 cm shows two peaks separated by about 0 \hbox to 0.0 pt { . } ^ { \prime \prime } 13 ( corresponding to 100-780 AU , using a distance range of 0.8 - 6 kpc ) .
This emission is interpreted as originating in an ionized equatorial torus-like structure , from whose edges the water maser emission might be arising .
We have detected weak OH 1612 MHz maser emission at V _ { LSR } \sim - 70 km s ^ { -1 } associated with IRAS 17347 - 3139 .
We derive a 3 \sigma upper limit of < 35 % for the percentage of circularly polarized emission .
Within our primary beam , we detected additional OH 1612 MHz maser emission in the LSR velocity ranges - 5 to -24 and - 90 to - 123 km s ^ { -1 } , associated with the sources 2MASS J17380406 - 3138387 and OH 356.65 - 0.15 , respectively .