Margarita Valdez-Gutierrez

Unveiling the Kinematics and Dynamics of Ionized Gas in the Nearby Irregular Galaxy NGC 4449

A detailed kinematic analysis of ionized gas in the nearby irregular galaxy NGC 4449 is presented. Observations are conducted in the spectral lines of Halpha and [SII]. Our scanning Fabry--Perot interferometric observations are presented from both a global as well as a local perspective. We have analysed the global velocity field, the spatially extended diffuse gaseous component (DIG), the HII region populations, and, furthermore, have determined the rotation curve based on the heliocentric radial velocities of the global Halpha spatial distribution. Our results for NGC 4449 show that the optical velocity field has a decreasing value in radial velocity along the optical bar from NE to SW. The DIG component that permeates the entire galaxy was analysed (up to a limiting surface brightness of ~ 3.165x10^-5 ergs cm

Kinematics of the Ionized Gas in Dwarf Irregular Galaxies

^-2 s^-1 steradian^-1). We find that the diffuse gas component presents peculiar kinematical features such as abrupt velocity gradients and highly supersonic velocity dispersions (sigma~4 times the values of the nearest HII regions) but that its kinematical and dynamical influence is important on both global and local scales. The optical rotation curve of this nearby irregular shows that the NE sector rotates like a solid body (V_rot~40 km s^-1 at R=2 kpc). For the SW side, our results are not conclusive; the behavior of the gas at those locations is chaotic. We conclude that the origin of such complex kinematics and dynamics is undoubtedly related to the aftermath of an interaction experienced by this galaxy in the past (abridged).

A Fourier Analysis of the Interacting Pair of Galaxies KPG 404 (NGC 5394/95)

Some preliminary results focused on the kinematics and dynamics of the ionized gas in the Local Group dwarf irregular galaxy IC10 are presented.

3D Studies of Recycling Signatures within Irregular Galaxies

We present a bi-dimensional Fourier analysis of near-infrared images of KPG 404 (NGC 5394/95). The 2D Fourier analysis shows that NGC 5394 is a H2β galaxy in the DP classification (Block & Puerari 1999). In contrast, NGC 5395 displays a very complex structure which needs a number of Fourier coefficients to be explained. A tightly wound m = 1 (DP class H1α) is the main structure, but other m = 1 and m = 2 coefficients (suggesting spiral arm modulation) are also present in the Fourier spectra. The complex structure of NGC 5395 also suggests a strong interaction in the pair. The m = 1 coefficients can represent a pseudo ring-type structure, resulting of a collision rather than a grazing passage. We conclude that the most probable scenario of the interaction in this pair should take into account a crossing of NGC 5394 through the disk of NGC 5395.

Uncovering Morphology from Dust: A NIR View of the Interacting Galaxy Pair NGC 5394/95

We present a 3D analysis based on Fabry-Perot data of some astronomical objects directly related to recycling processes within the irregular galaxies NGC4449 and IC1613.

On the Behavior of the Ionized Gas in NGC 4449

We present a near infrared 2D Fourier analysis of the interacting pair of galaxies NGC 5394/95 to get insight on its morphology. Our analysis shows that NGC 5394 is a H2s galaxy in the DP classification (Block and Puerari 1999). NGC 5395, in contrast, displays a very complex structure which needs a number of Fourier coefficients to be explained. A tightly wound m = 1 (DP class H1α) is the main structure, but other m = 1 and m = 2 coefficients (suggesting modulation) are also present in the Fourier spectra. The complex structure of NGC 5395 also suggest a strong interaction in the pair. The m = 1 coefficients can represent a pseudo ring-type structure, resulting of a collision rather than a passage.

The influence of massive stars in the interstellar medium of IC 1613: the supernova remnant S8 and the nebula S3 associated with a WO star.

In this contribution we report some preliminary results derived from the global content of ionized gas in the nearby irregular galaxy NGC 4449.