Contents
Images
Upload your image
DSS Images Other Images
Related articles
Metallicity Indices for Multi-Population Models.II.Bulges of Galaxies
We report metallicity indices in the Lick system (Hβ, Fe52, Fe53,NaD, Mg_2_) for a sample of 45 spiral bulges in the southern hemisphere.The velocity dispersion σ was also derived for each object. Spiralbulges and elliptical galaxies show a continuity in diagrams like theplane Mg_2_- or σ-Mg_2_. Using calibrations derived fromchemical evolutionary models, we estimated metallicities and abundanceratios for those bulges. The sample mean metallicity is [Fe/H]= -0.19+/- 0.27(rmsd), and the mean abundance ratios are [Mg/Fe] = 0.46 +/-0.11 (rmsd) and [Na/Fe] = 0.45 +/- 0.19(rmsd). These abundances suggestthat spiral bulges (like E's) were chemically enriched by type IIsupernovae, and that the main star formation era occurred in a timescale of the order of 1-2 Gyr.
| The Catalog of Southern Ringed Galaxies
The Catalog of Southern Ringed Galaxies (CSRG) is a comprehensivecompilation of diameters, axis ratios, relative bar position angles, andmorphologies of inner and outer rings, pseudorings, and lenses in 3692galaxies south of declination -17 deg. The purpose of the catalog is toevaluate the idea that these ring phenomena are related to orbitalresonances with a bar or oval in galaxy potentials. The catalog is basedon visual inspection of most of the 606 fields of the Science ResearchCouncil (SRC) IIIa-J southern sky survey, with the ESO-B, ESO-R, andPalomar Sky surveys used as auxiliaries when needed for overexposed coreregions. The catalog is most complete for SRC fields 1-303 (mostly southof declination -42 deg). In addition to ringed galaxies, a list of 859mostly nonringed galaxies intended for comparison with other catalogs isprovided. Other findings from the CSRG that are not based on statisticsare the identification of intrinsic bar/ring misalignment; bars whichunderfill inner rings; dimpling of R'1pseudorings; pointy, rectangular, or hexagonal inner or outer ringshapes; a peculiar polar-ring-related system; and other extreme examplesof spiral structure and ring morphology.
| A redshift map of the Triangulum Australe-Ara region - Further indication that Centaurus and Pavo are one and the same supercluster
Existing redshifts for the region RA 15 h 30 m to 18 h 40 m, Dec. -50deg to -70 deg, have been supplemented by new observations. Aconspicuous excess of galaxies with velocity of about 4700 km/s forms anapparent link between Centaurus and Pavo. A number of possible nearbyvoids are identified.
| Southern Galaxy Catalogue.
Not Available
|
Submit a new article
Related links
Submit a new link
Member of following groups:
|
Observation and Astrometry data
Catalogs and designations:
|
