G. J. Carranza

Kinematics of the Central Regions of NGC 1672

Resumen en: We present two-dimensional spectroscopy and broad band imaging of the LINER galaxy NGC 1672. The velocity field and morphology of the central 2kpc indica...

CATALOG OF DOUBLE NUCLEUS DISK GALAXIES

We have compiled a catalog of disk galaxies that have a double nucleus, through systematic examination of existing catalogs and publications. The Catalog of Double Nucleus Disk Galaxies includes 107 objects, together with their basic data. The aim of the catalog is to provide a more systematic and homogeneous basis for the study of the relevance of galaxy interactions and minor mergers in the formation of these double nuclei. We have also investigated possible correlations between geometric and photometric parameters of the double nuclei and their host galaxies. The preliminary results indicate the presence of several significant correlations that should be considered in any theoretical scenario describing minor mergers and disk galaxy evolution.

Photometry and Kinematics of Two Minor Merger Candidate Galaxies

We observationally investigate the properties of disk galaxies undergoing minor merger or capture events. In this context, the properties of two double-nucleus candidate galaxies, ESO 381-IG 23 and MCG -3-35-14, are analyzed. Both are disk-dominated Sc-Scd galaxies that show a bright knot superposed on their disk body. The size and surface brightness of these knots are in both cases comparable to those of the galaxy nucleus, which has led previous work to classify these galaxies as double-nucleus galaxies. We present results from observations made with the SOAR 4.1 m, CASLEO 2.15 m, and Bosque Alegre 1.54 m telescopes. We determined the values for the apparent and absolute magnitudes of the nuclei and the bright regions and analyzed the surface brightness profiles and colors. We also study the kinematics of the galaxies via their rotation curves. Analytical mass models were fitted under the constraints of both kinematic and photometric observational data. It is found that ESO 381-IG 23 has an absolute magnitude MB = -19.59 and mass = (3.0 ± 0.2) × 1010 ⊙, and its nuclear spectrum shows strong emission lines typical of starbursts. MCG -3-35-14 has MB = -19.97 and = (9.6 ± 0.5) × 1010 ⊙. Both galaxies are morphologically normal disk galaxies. They have a bulge-to-disk ratio of ~0.1 and show no significant signatures of dynamical perturbation in their rotation curves. The secondary nuclei candidates are found to be giant H II regions, rather than nuclei of captured companions. They have masses of (2.2 ± 0.2) × 106 ⊙ (ESO 381-IG 23) and (4.1 ± 0.2) × 106 ⊙ (MCG -3-35-14), and ages of 6.6 ± 0.1 and 8.0 ± 1.0 Myr, respectively.

Is the (J-Ks) excess in the nuclear region of NGC 1241 due to dust or to C-stars?

NGC 1241 is a Sy 2 galaxy with a 1.4 kpc circumnuclear ring (CNR) of star formation revealed in Paα. A 0.3 kpc long Paα emitting bar centered on the nucleus is present, apparently without associated absorption features. GEMINI (+QUIRC+Hokupa) IR pixel-photometry reveals instead an azimuthally symmetric ( J − K s ) color which is redder at the nucleus than at the CNR. This property may well be due to the increasing importance of dust when going from the ring inward into the nucleus. Nevertheless the ( V − H ) color does not indicate special absorption conditions in the nucleus with respect to the CNR, and no absorption features are evident, as normally expected near emitting bars. Then, we propose as an alternative explanation an excess of C-stars in the nuclear region which decreases outwards until reaching the CNR and its colors. We have compared the pixel color-magnitude diagram with the 2-MASS ( J − K s ) vs. K s diagram for the Large Magellanic Cloud: about 5×10 2 C-stars and 2.5×10 4 AGB Oxygen-rich stars inside r ∼50 pc, are enough to reproduce the observed nuclear tip in the diagram. This stars would release gas that, gravitationally bounded, pollutes the nuclear environment and could amount 10 −2 to 10 −1 M

Circumnuclear Structures in the Interacting Seyfert Galaxy NGC 1241: Kinematics and Optical/Infrared Morphology

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First Spectroscopic Results on NGC 151, NGC 1433, NGC 6221 and Fairall 9 Obtained at Bosque Alegre Station

yr −1 of fuel for the central engine during the lifetime of stars with masses 2 M

Análisis Interferométrico de las Burbujas DEM 164; DEM 165; DEM 202-207; DEM 208; y DEM 221 en la Nube Mayor de Magallanes

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Spectroscopy Study of the Planetary Nebulae H1-3

. This scenario may also explain the observed increased strength of the CN-bands in the stellar populations of Sy 2 nuclei, and the recent claim of a significant contribution of intermediate age stars to the optical continuum of low luminosity AGNs. To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html