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Progress in the Study of Galaxies: Structures, Collective Phenomena and Methods
The review contains the important achievements in dynamics of thegalactic disks. Among them there are I. New structures discoveredrecently: • giant vortices (including giant anticyclone in theSolar vicinity); • slow bar; • inner oscillating structurewithin spiral arms similar that of enveloped soliton; • chaoticstreamlines in the velocity field of the gaseous disk of a real galaxy.II. New collective phenomina discovered recently: • newoverreflection instability initiating ‘mini-spiral’ in theinnermost central parsec of Galaxy; • large-scale convection causedby nonlinear interaction of density wave with disk gas; •non-kolmogorovian spectrum of weak turbulence corresponding to theobserved one in the • Solar vicinity. III. New methods worked outrecently: • reconstruction of full three-dimensional vector fieldof gas velocity from the observed line-of- • sight velocity field;• observational test for verification of the wave-nature of thespiral arms; • observational test to distinguish two types ofvertical motions: warp and z-motions in the • density wave; •derivation of correct system of two-dimensional dynamical equations fromthe initial three- • dimensional one.
| An image database. II. Catalogue between δ=-30deg and δ=70deg.
A preliminary list of 68.040 galaxies was built from extraction of35.841 digitized images of the Palomar Sky Survey (Paper I). For eachgalaxy, the basic parameters are obtained: coordinates, diameter, axisratio, total magnitude, position angle. On this preliminary list, weapply severe selection rules to get a catalog of 28.000 galaxies, wellidentified and well documented. For each parameter, a comparison is madewith standard measurements. The accuracy of the raw photometricparameters is quite good despite of the simplicity of the method.Without any local correction, the standard error on the total magnitudeis about 0.5 magnitude up to a total magnitude of B_T_=17. Significantsecondary effects are detected concerning the magnitudes: distance toplate center effect and air-mass effect.
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