Universidad Complutense de Madrid
E-Prints Complutense

Global velocity field and bubbles in the blue compact dwarf galaxy Mrk 86

Impacto

Downloads

Downloads per month over past year

Gil de Paz, Armando and Zamorano Calvo, Jaime and Gallego Maestro, Jesús (1999) Global velocity field and bubbles in the blue compact dwarf galaxy Mrk 86. Monthly notices of the Royal Astronomical Society, 306 (4). pp. 975-987. ISSN 0035-8711

[img]
Preview
PDF
1MB

Official URL: http://dx.doi.org/10.1046/j.1365-8711.1999.02595.x




Abstract

We have studied the velocity field of the blue compact dwarf galaxy Mrk 86 (NGC 2537) using data provided by 14 long-slit optical spectra obtained in 10 different orientations and positions. This kinematical information is complemented with narrow-band ([O III]5007 Å and Hα) and broad-band (B, V, Gunn r and K) imaging. The analysis of the galaxy global velocity field suggests that the ionized gas could be distributed in a rotating inclined disc, with projected central angular velocity of Ω=34 km s^−1 kpc^−1. The comparison between the stellar, H I and modelled dark matter density profile indicates that the total mass within its optical radius is dominated by the stellar component. Peculiarities observed in its velocity field can be explained by irregularities in the ionized gas distribution or local motions induced by star formation.
Kinematical evidences for two expanding bubbles, Mrk 86-B and Mrk 86-C, are given. They show expanding velocities of 34 and 17 km s^−1, Hα luminosities of 3×10^38 and 1.7×10^39 erg s^−1, and physical radii of 374 and 120 pc, respectively. The change in the [S II]/Hα, [N II]/Hα, [O II]/[O III] and [O III]/Hβ line ratios with the distance to the bubble precursor suggests a diminution in the ionization parameter and, in the case of Mrk 86-B, an enhancement of the shock-excited gas emission. The optical-near-infrared colours of the bubble precursors are characteristic of low-metallicity star-forming regions (∼0.2 Z_⊙) with burst strengths of about 1 per cent in mass.


Item Type:Article
Additional Information:

© 1998 RAS.
Based on observations made with the Jacobus Kapteyn and Isaac Newton telescopes operated on the island of La Palma by the Royal Greenwich Observatory in the Spanish Observatorio del Roque de los Muchachos of the Instituto Astrofísico de Canarias. Based also in observations collected at the German-Spanish Astronomical Centre, Calar Alto, Spain, operated jointly by the Max-Plank-Institut für Astronomie (MPIA), Heidelberg, and the Spanish National Commission for Astronomy. The United Kingdom Infrared Telescope is operated by the Joint Astronomy Centre on behalf of the U.K. Particle Physics and Astronomy Council. We would like to thank C. Sánchez Contreras and L. F. Miranda for obtaining the high resolution Hα spectra, C. Jordi and D. Galadí for obtaining the V image, and A. Aragón Salamanca who provided the K image. We also thank J. Cenarro and C. E. García Dabó for stimulating conversations. We are indebted to the referee, Dr. A. Burkert, for many helpful comments and corrections. A. Gil de Paz acknowledges the receipt of a Formación del Profesorado Universitario fellowship from the Spanish MEC. This research was supported by the Spanish Programa Sectorial de Promoción General del Conocimiento under grant PB96-0610.

Uncontrolled Keywords:Radio-continuum observations; Enhanced galactic winds; Dark-matter halos; H-II regions; Star-formation; Stellar populations; Interstellar-medium; Optical structure; Spiral galaxies; Co observations
Subjects:Sciences > Physics > Astrophysics
Sciences > Physics > Astronomy
ID Code:34342
Deposited On:18 Nov 2015 15:42
Last Modified:10 Dec 2018 15:05

Origin of downloads

Repository Staff Only: item control page