The Eye of the Tornado – an isolated, high mass young stellar object near the Galactic centre

Astrophysics, abstract
astro-ph/0308262

From: Michael Burton <m.burton@unsw.edu.au>

Date: Fri, 15 Aug 2003 08:24:55 GMT   (91kb)

Authors:
M.G. Burton,
J.S. Lazendic,
F. Yusef-Zadeh,
M. Wardle

Comments: 25 pages, including 5 figures. Submitted to Monthly Notices of the
Royal Astronomical Society on 15/08/03

We present infrared (AAT, UKIRT) and radio (VLA, SEST) observations of the
Eye of the Tornado, a compact source apparently near the head of the Tornado
Nebula. The near-infrared Br-gamma and He I lines are broad (FWHM 40 and 30
km/s, respectively) and have a line centre at Vlsr = -205 km/s. This
corresponds to a feature at the same velocity in the 12CO J=1-0 line profile.
The kinematic velocity derived from Galactic rotation places the Eye at the
distance of the Galactic Centre (i.e. 8.5 kpc) and separated (probably
foreground) from the Tornado Nebula. Four knots of emission are seen in the
Br-gamma line and at 6 and 20 cm. Together with the flat radio spectral index,
we confirm that the Eye contains ionized gas, but that this is embedded within
a dense molecular core. The spectral energy distribution can be modelled as a
two-component blackbody + greybody, peaking at far-IR wavelengths. The knots
are UC HII regions, and the core contains a luminous (2 x 10^4 Lsun), embedded,
massive young stellar source. We also propose a geometrical model for the Eye
to account for both its spectral energy distribution and its morphology.

References and citations for this submission:

SLAC-SPIRES HEP (refers to ,
cited by, arXiv reformatted)