S. Curiel et al., HIGH-VELOCITY AMMONIA EMISSION ASSOCIATED WITH THE YOUNG STELLAR OBJECT SERPENS FIRS-1, The Astrophysical journal, 456(2), 1996, pp. 677-685
We have performed VLA, Haystack, and Effelsberg 100 m ammonia observat
ions of the molecular core associated with the highly collimated radio
continuum jet of the very young stellar object (YSO) Serpens FIRS 1.
An analysis of the overall morphology, kinematics, and excitation of t
he ambient cloud core is presented. In particular, the mean rotational
temperature derived over a region of 2' x 2' around FIRS 1 is found t
o be 12 K, whereas it increases to 30 K at distances within 6 '' from
FIRS 1, indicating that FIRS 1 is the dominant energy source in the cl
oud core. By averaging the blueshifted (V-LSR = -6.1 --> +5.7 km s(-1)
) and redshifted (V-LSR = +10.7 --> +22.5 km s(-1)) spectral channels
of the VLA data with respect to the ambient cloud velocity (V-LSR = 7.
0-9.4 km s(-1)), we have detected an excess of emission (above the exp
ected continuum) that we identify as high-velocity ammonia emission as
sociated with the YSO FIRS 1. The blue- and redshifted emissions seem
to have a bipolar morphology, suggesting that they trace a bipolar amm
onia outflow of similar to 20 '' in size and aligned with the radio co
ntinuum jet. We identify this high-velocity ammonia emission, with an
estimated mass M(H-2) similar or equal to 0.2 [XNH(3)/10(-8))](-1) M.,
as associated with the molecular gas entrained by the radio jet. In a
ddition, NH3 (1,1), (2,2), and (3,3) spectra of this region taken with
the Haystack and the Effelsberg 100 m telescopes show ammonia emissio
n at even higher velocities (up to similar to 30-40 km s(-1) from the
line center) than those observed with the VLA (less than or similar to
20 km s(-1)), suggesting that the VLA observations cover only a fract
ion of the velocity range of the ammonia outflow. New VLA ammonia obse
rvations covering a higher velocity range are needed to fully map this
high-velocity molecular emission and to confirm its bipolar distribut
ion.