The outflow structure of NGC 6537.

Cuesta, L.; Phillips, J. P.; Mampaso, A.
Bibliographical reference

Astronomy and Astrophysics, v.304, p.475

Advertised on:
12
1995
Number of authors
3
IAC number of authors
2
Citations
22
Refereed citations
22
Description
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.