INVESTIGADORES
HÄGELE Guillermo Federico
artículos
Título:
Kinematics of gas and stars in the circumnuclear star-forming ring of NGC3351
Autor/es:
HÄGELE, GUILLERMO F.; DÍAZ, ÁNGELES I.; CARDACI, MÓNICA V.; TERLEVICH, ELENA; TERLEVICH, ROBERTO
Revista:
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2007 vol. 378 p. 163 - 178
ISSN:
0035-8711
Resumen:
We have measured gas and stellar velocity dispersions in five
circumnuclear star-forming regions (CNSFRs) and the nucleus of the
barred spiral galaxy NGC3351. The stellar dispersions have been obtained
from high-resolution spectra of the CaII triplet (CaT) lines at
λλ8494, 8542, 8662Å, while the gas velocity
dispersions have been measured by Gaussian fits to the Hβ
λ4861Å line on high-dispersion spectra.
The CNSFRs, with sizes of about 100 to 150pc in diameter, are seen to be
composed of several individual star clusters with sizes between 1.7 and
4.9pc on a Hubble Space Telescope (HST) image. Using the stellar
velocity dispersions, we have derived dynamical masses for the entire
star-forming complexes and for the individual star clusters. Values of
the stellar velocity dispersions are between 39 and 67kms-1.
Dynamical masses for the whole CNSFRs are between 4.9 ×
106 and 4.3 × 107Msolar and
between 1.8 and 8.7 × 106Msolar for the
individual star clusters.
Stellar and gas velocity dispersions are found to differ by about
20kms-1 with the Hβ lines being narrower than both the
stellar lines and the [OIII]λ5007Å lines. We have found
indications for the presence of two different kinematical components in
the ionized gas of the regions. The radial velocity curve shows
deviation from circular motions for the ionized hydrogen consistent with
its infall towards the central regions of the galaxy at a velocity of
about 25kms-1. To disentangle the origin of these two
components it will be necessary to map these regions with high spectral
and spatial resolution and much better signal-to-noise ratio in
particular for the O2+ lines.