Mixed early and late-type properties in the bar of NGC 6221: Evidence for evolution along the Hubble sequence?

Autor(en)
Juan Carlos Vega Beltran, Werner Zeilinger, P Amico, Mathias Schultheis, Enrico Maria Corsini, Jose Gabriel Funes, John E. Beckman, Francesco Bertola
Abstrakt

Rotation curves and velocity dispersion profiles are presented for both the stellar and gaseous components along five different position angles (PA = 5°, 50°, 95°, 125°, and 155°) of the nearby barred spiral NGC 6221. The observed kinematics extends out to about 80? from the nucleus. Narrow and broad-band imaging is also presented. The radial profiles of the fluxes ratio [N II] (? 6583.4 A°)/Ha reveal the presence of a ring-like structure of ionized gas, with a radius of about 9? and a deprojected circular velocity of about 280 km s-1. The analysis of the dynamics of the bar indicates this ring is related to the presence of an inner Lindblad resonance (ILR) at 1.3 kpc. NGC 6221 is found to exhibit intermediate properties between those of the early-type barred galaxies: the presence of a gaseous ring at an ILR, the bar edge located between the ILR's and the corotation radius beyond the steep rising portion of the rotation curve, the dust-lane pattern, and those of the late-type galaxies: an almost exponential surface brightness profile, the presence of Ha regions along all the bar, the spiral-arm pattern. It is consistent with scenarios of bar-induced evolution from later to earlier-type galaxies.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
Instituto de Astrofísica de Canarias (IAC), European Southern Observatory (Germany), Università degli Studi di Padova, Vatican Observatory
Journal
Astronomy & Astrophysics Supplement Series
Band
131
Seiten
105-114
Anzahl der Seiten
10
ISSN
0365-0138
Publikationsdatum
1998
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/mixed-early-and-latetype-properties-in-the-bar-of-ngc-6221-evidence-for-evolution-along-the-hubble-sequence(7cbcf520-c826-4f2e-b24a-333ee82a5950).html