arXiv subjects

V. E. Karachentseva

Publications and source records attributed to V. E. Karachentseva.

58 records · Page 4Linked to original sources

arXiv2000

A Dwarf Galaxy Survey in the Local Volume

We are carrying out a comprehensive multi-wavelength study of dwarf galaxies in the Local Volume (< 5 Mpc). After our all-sky survey more than doubled the dwarf census we are now measuring structural parameters, integrated properties, and velocities. Our 200-orbit HST snapshot program yields stellar content, star formation history, and TRGB distances. We can thus study the morphology-density relation in galaxy groups in three dimensions, the influence of environment on galaxy evolution, and the universality of the metallicity-surface brightness-luminosity relation.

astro-ph↗

arXiv1999

HI observations of nearby galaxies I. The first list of the Karachentsev catalog

We present HI observations of the galaxies in the first list of the Karachentsev catalog of previously unknown nearby dwarf galaxies (Karachentseva & Karachentsev 1998). This survey covers all known nearby galaxy groups within the Local Volume (i.e. within 10 Mpc) and their environment, that is about 25% of the total sky. A total of 257 galaxies have been observed with a detection rate of 60%. We searched a frequency band corresponding to heliocentric radial velocities from -470 km/s to about +4000 km/s. Non-detections are either due to limited coverage in radial velocity, confusion with Local HI (mainly in the velocity range -140 km/s to +20 km/s, or lack of sensitivity for very weak emission. 25% of the detected galaxies are located within the Local Volume. Those galaxies are dwarf galaxies judged by their optical linear diameter (1.4 +/- 0.2 kpc on the average), their mean total HI mass (4.6 E7 solar masses), and their observed linewidths (39 km/s).

astro-ph↗

arXiv1999

The dwarf spheroidal galaxy DDO 44: stellar populations and distance

We present ground-based and HST WFPC2 imaging of the nearby low surface brightness dwarf spheroidal galaxy DDO 44. For the first time DDO 44 was resolved into stars. The resulting color-magnitude diagram for about 1290 stars shows the red giant branch with a tip at I=(23.55+-0.15) mag, which yields a distance of (3.2+-0.2) Mpc consistent with membership of DDO 44 in the NGC 2403 group. The linear separation of DDO 44 from NGC 2403 is 75 kpc on the sky and (30+-450) kpc along the line of sight. The relationship between the dwarf galaxy's absolute R magnitude of -13.1 mag, its central surface brightness of 24.1 mag/square arcsec, and its mean metallicity of -1.7 dex follow the trend for other nearby dwarf spheroidal galaxies. One globular cluster candidate has also been identified in DDO 44.

astro-ph↗

arXiv1999

New Dwarf Galaxies in the IC342/Maffei Group

We report detection of HI-emission from three 'new' dwarf galaxies Perseus A, Perseus B, and Camelopardalis D in the IC342/Maffei group of galaxies and of Draco A. The actual number of (probable) members of this group increases to 19 galaxies. Its velocity dispersion is 87 km/s. With a distance of 2.2+-0.5 Mpc this group is the nearest to the Local Group and might have considerable dynamical influence on the Local Group.

astro-ph↗