... Teuben, P. J. 2003, in ASP Conf. ... The observed light distribution gives many clues about the different components disk galaxies seem to be made up of (bulge, disk, bars etc.), though it was not until the velocity field of tracer material such as HI in the outer parts of disk galaxies was studied (see Sofue & Rubin, 2001, for an excellent recent review), that an unseen component was postulated to exist. ... Velocity fields are commonly derived from a datacube by fitting gaussians or taking moments...

... According to the most popular cosmological paradigm, the greater part of the galaxy mass is accumulated in the dark matter halo. ... The polar ring galaxies (PRGs) reveal external rings or disks of gas, dust and stars rotating in a plane roughly perpendicular to the disk of the central galaxy. ... The shape of the dark halo in the model was chosen so as to achieve the best fit to the observed rotation of both galaxies themselves and their polar rings. ... The SPRC-7 galaxy. ...

Next: Simulations Up: Maximum Likelihood Estimation of Previous: Introduction . The properties of an ensemble of faint galaxies can be defined by the distribution of the parameters of the models that best fit each individual object. ... The model also includes instrumental parameters, such as the sky background (estimated locally) and amplitude of the noise. ... The probability of the observed value is then computed for each pixel using the adopted error distribution. ...

Next: Star Formation Rate and Up: No Title Previous: Calculation of Evolutionary Tracks . To start calculations, we choose the distributions of the initial binary parameters: the mass of the primary ZAMS component, , binary mass ratio, , orbital separation a . ... whereas the mass ratio distribution is not. ... The zero assumption often made is that the mass ratio distribution has a flat shape, that is binaries with a high mass ratio occur as frequently as those with equal masses. ...

In this gallery are many images of Low Surface Brightness Galaxies which have recently been discovered and analyzed. ... The central surface brightness of this galaxy is 24.28 . Malin 2 This galaxy is another huge disk galaxy with a scale length of 15 kpc and a redshift of 15000 km/a. The high surface brightness knot in one of its spiral arms actually has the same color, luminosity and H-alpha equivalent width as the entire Large Magellanic Cloud . ... Truly it is a Low Surface Brightness Galaxy. ...

... Research . ... The major problem in HVC research is the unknown distance towards most of the HVCs. ... Thilker et al. (2004) used the Green Bank Telescope (GBT) to map an area of $7^{\circ} \times 7^{\circ}$ around M31 in H i . They discovered a population of HVCs located within a projected distance of about $50~\mathrm{kpc}$ from M31. ... 2004). ... The remaining HVCs around M31 are isolated in position and velocity and may represent primordial, dark-matter-dominated clouds. ...

... We have made observations of the Perseus cluster with the Westerbork Telescope at 610 MHz. ... Several newly detected sources are identified with cluster galaxies. ... No evidence is found for the existence of the previously reported ~ 65'x25' cluster halo, 3C 84B. Key words: radio galaxies - clusters - tailed radio sources buoyancy The Perseus Cluster of galaxies is one of the most fascinating systems accessible to extragalactic astronomers. ...

The radial distribution of metallicity of star-forming galaxies in a galaxy cluster can inform us about the mass assembly and enrichment history of the galaxy cluster. ... Both galaxy clusters are cool-core clusters at redshift z т?? ... The gas-phase metallicity of star- forming galaxies in MACS1115+01 exhibit anti-correlation with projected distance т??0.15 ТБ 0.08 dex/Mpc, whereas the radial metallicity distribution of RXJ1532+30 is statistically flat (т??0.09 ТБ 0.12 dex/Mpc). ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

... The search for distant objects which can be both galaxies and quasars is one of the most important problems of observational astrphysics, because it allows one to determine cosmological parameters connected with the time of appearence and evolution of stellar systems, large scale structure of the Universe. ... Radio galaxies are important objects to be studied because they are sources of infrared-optical-ultraviolet continuum, emission lines and continual radio emission. ...

... Nonparametric density estimation drops these restrictions 8 Nonparametric Density Estimation 12 density 0 0.0 2 4 6 8 10 0.1 0.2 0.3 redshift 0.4 0.5 Histogram of 1,425 galaxy redshifts. 9 Nonparametric Density Estimation 12 density 0 0.0 2 4 6 8 10 0.1 0.2 0.3 redshift 0.4 0.5 Compared with best fitting gamma distribution. ... 13 Nonparametric Density Estimation 12 density 0 0.0 2 4 6 8 10 0.1 0.2 0.3 redshift 0.4 0.5 Parametric versus nonparametric estimate (kernel density estimate). ...

... 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Nuclear activity and environment Effect of environment on AGN is not completely clear yet. ... 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Effect of the mass Mass slices ­ optical and radio AGN overall interaction one-on-one interaction relative location 05/09/2013 Galaxy Evolution over Five Decades - Cambridge 2013 Stratified study Stratifed study that considers several strata of mass. ...

. Distribution of Supernovae according to their parent galaxies' recession velocity. This graph shows the distribution of SNe according to the recession velocity of their parent galaxies. This graph is kept up to date till SN 2000ek . Along X-axis there are all velocity bands so that you have to read in this way: for example, the band on the graph marked as 2000 takes in all parent galaxies' recession velocities faster than 1000 until 2000 Km/sec.

polimodel -- Produce model linear polarization and position angle images . ... Whether to apply random errors to output polarization and position angle values. seed = "" [integer] . ... This task produces a model linear polarization image and corresponding position angle image from an input image assumed to represent intensity (Stokes I parameter). ... A threshold for the input image can be defined such that polarization and position angle are not computed for input values less than this threshold. ...

polimodel -- Produce model linear polarization and position angle images . ... Whether to apply random errors to output polarization and position angle values. seed = "" [integer] . ... This task produces a model linear polarization image and corresponding position angle image from an input image assumed to represent intensity (Stokes I parameter). ... A threshold for the input image can be defined such that polarization and position angle are not computed for input values less than this threshold. ...

The Extragalactic ALFA Zone of Avoidance team is mapping the distribution of low-Galactic-latitude galaxies and large scale structures through detection of galaxies' 21-cm emission with ALFA. This Zone of Avoidance (ZOA) survey finds new HI galaxies which lie hidden behind the Milky Way, and also provides redshifts and other HI parameters for partially-obscured galaxies known at other wavelengths. ... Discovery and Follow-up of a Nearby Galaxy from the Arecibo Zone of Avoidance Survey. ...

... Impact on source motion in Galactic coordinate system is given by Kovalevsky (2003), Malkin (2011) l cos b = -A sin l, b = -A cos l sin b, where A = R0 02 /c is the galactocentric acceleration called hereafter the GA constant. ... We just have to return to the traditional many-centuries-old astrometric practice of modelling the position of a celestial object as a linear trend with two parameters: the position at the initial (conventional) epoch and the apparent (proper) motion. ... 2011). ...

... arXiv.org . ... Although great progress has been made in modelling the disk with radiative transfer models able to reproduce the spectral energy distribution (SED) of Herbig Ae stars, the constraints brought by images have not been yet fully exploited. Here, we are interested in checking if these new observational imaging constraints can be accounted for by predictions based on existing models of passive centrally irradiated hydrostatic disks made to fit the SEDs of the Herbig Ae stars. ...

Scale-heights of the Galactic disk subsytems with different ages and metallicities . V.Marsakov & Yu. ... It is based on the fact, that all stars cross the disk plane several times during their Galactic orbital period. ... We have used our representative sample of nearby disk F2-G2 stars Marsakov & Shevelev (1995) in which fundamental stellar parameters was determined on the basis of published date on uvby-photometry, proper motion and radial velocities. ... Marsakov V.A., Shevelev Yu.G. Bull. ...

... A list of spectrum files from a set of observations, referring to one RGS instrument and one spectral order. These spectra files must be produced using the attstyle=user and associated parameters from a call to rgsproc . ... A list of accompanying event list files, in the same order as the spectra files. ... If this parameter is set to yes, the spectra files of the input lists will be combined to produced a combined spectrum file each for both spectra and background spectra files. filermf . ...