Bibcode
Cuesta, L.; Phillips, J. P.; Mampaso, A.
Referencia bibliográfica
Astronomy and Astrophysics, v.304, p.475
Fecha de publicación:
12
1995
Revista
Número de citas
22
Número de citas referidas
22
Descripción
We present high and low resolution spectroscopy and narrow-band imaging
of the unusual bipolar outflow source NGC 6537. As a consequence, we are
able for the first time to construct large scale velocity maps of this
source; note the presence of strongly variable core outflow densities,
rising to a peak value n_e_~1.7x10^4^cm^-3^; find evidence for
substantial core ionization stratification; and demonstrate the presence
of a spatially extended, intermediate velocity wind extending over a
range {DELTA}v_I_=~700km/s, together with a more tightly constrained
component having {DELTA}v=~4400km/s. This latter wind appears co-spatial
with the slower, higher intensity core emission, and may be responsible
for driving denser clumps of material to a typical velocity
v_exp_~18km/s. Temperatures appear to vary significantly over the core,
from a peak value T_e_=~1.0x10^4^K close to the nucleus, to =~0.9x10^4^K
for projected radial offsets of 5", whilst extinction is more or less
constant, yielding a mean estimate A_v_=~3.4+/-0.2mag. Application of a
shock outflow model suggests that most of these features are readily
explained providing wind mass-loss rates are of order
˙(M)_*_~6x10^-8^-6x10^-7^Msun_/yr, and the flow is
strongly collimated by an interior disk. In particular, we are able to
provide excellent simulations for both the complex kinematics, and
unusual bipolar configuration.