Observation of narrow polar jets in the nascent wind of oxygen-rich AGB star EP Aqr

Using ALMA observations of (CO)-C-12(2-1), (SiO)-Si-28(5-4), and (SO2)-S-32(16(6,10)-17(5,13)) emissions of the circumstellar envelope of AGB star EP Aqr, we describe the morpho-kinematics governing the nascent wind. Main results are as follows: (1) Two narrow polar structures, referred to as jets, launched from less than 25 au away from the star, build up between similar to 20 and similar to 100 au to a velocity of similar to 20 km s(-1). They fade away at larger distances and are barely visible in CO data. (2) SO2, SiO, and CO emissions explore radial ranges reaching, respectively, similar to 30, 250, and 1000 au from the star, preventing the jets to be detected in SO2 data. (3) Close to the star photosphere, rotation (undetected in SiO and CO data) and isotropic radial expansion combine with probable turbulence to produce a broad SO2 line profile (similar to 7.5 km s(-1) full width at half-maximum). (4) A same axis serves as axis of rotation close to the star, as jet axis and as axi-symmetry axis at large distances. (5) A radial wind builds up at distances up to similar to 300 au from the star, with larger velocity near polar than equatorial latitudes. (6) Lambda sharp depletion of SiO and CO emissions, starting near the star, rapidly broadens to cover the whole blue-western quadrant, introducing important asymmetry in the CO and particularly SiO observations. (7) The C-12/C-13 abundance ratio is measured as 9 +/- 2. (8) Plausible interpretations are discussed, in particular assuming the presence of a companion.