A Test of Galaxy Evolutionary Models Via Angular Sizes M. Im S. Casertano, R. E. Griffiths, & K. U. Ratnatunga (The Johns Hopkins University) The relationship between angular size, magnitude, and redshift of faint galaxies is explored as a potential tool to distinguish between different galaxy evolutionary models. ... The mild lumi­ nosity evolution model predicts more luminous galaxies of large angular size at high redshift, as does a standard no evolution model. ... 25) with redshift higher than z ? ...

... Our resulting sample of ELGs presented in Tables 2 and 3 is not artificially biased to any specific type of galaxies. ... Since we are looking for selection of a sample of Case BCGs, it is interesting to examine how the detected BCGs are connected with Case emission-line codes. ... Altogether BCGs comprise about 60 % of all Case ELGs which display emission lines in our spectra, or about 44 % of all Case galaxies with some emission-line code. ... Among those with the code ``w'' about 40 % are BCGs. ...

The project of the informational system creation on the problem of evolution of radio galaxies, as a part of the "Big Trio" project aimed on studing of distant radio galaxies, is designed. This system allows a user to operate with simulated curves of spectral energy distributions (SED) to estimate ages and redshifts by photometry data. Authors use SEDs of several models for different types of galaxies. ... The HTTP and e-mail access is organized to this system. ...

... Posted by hlee . ... Click for what was appeared in arXiv this week. Continue reading ?[ ... Category: arXiv , MCMC , Uncertainty | ... Since I began to subscribe arxiv/astro-ph abstracts, from an astrostatistical point of view, one of the most frequent topics has been photometric redshifts . ... Just searching by photometric redshifts in google scholar and arxiv.org provides more than 2000 articles since 2000. ... Category: Algorithms , arXiv , Data Processing , Galaxies , Stat | ...

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. ...

... 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. ...

... ATNF Home . ... About ATNF overview . News | ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . ... Mopra radio telescope . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... Now, new Australia Telescope observations of the polar ring galaxy NGC 4650a suggest that the dark matter in this galaxy lies in a flattened distribution aligned with the polar ring. ...

... 1 Figure 1: The density distribution in R­Z plane Figure 2: The luminosity distribution in R­Z plane for Maxwellian kick velocity (75 km/s) 2 Figure 3: The luminosity distribution in R­Z plane for Maxwellian kick velocity (150 km/s) n(R; Z) = nHI + 2 \Delta nH2 nH2 = n 0 \Delta exp џ \GammaZ 2 2 \Delta (70pc) 2 – If 2kpc џ R џ 3:4kpc, then nHI = n 0 \Delta exp џ \GammaZ 2 2 \Delta (140pc \Delta R=2kpc) 2 – ; For R џ 2kpc n(R; Z) was assumed to be constant: n(R ! ...

... Colours of stars and galaxies hold information on intrinsic and extrinsic parameters, such as stellar temperatures and galaxy populations, selective absorption and colour changes due different dust contents and inclination angles of galaxies, as well as galaxy redshifts and evolution. ... The colour magnitude diagram of 65000 galaxies to which all above-mentioned quantities and others contribute can only be explained by comparison with simulations. ... Colours are also of technical help. ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2001 September 4 . 2dF Sees Waves of Galaxies . Credit: Matthew Colless ( ANU ) et al. , 2dF Galaxy Redshift Survey . ... The 2dF system measures galaxy redshifts , allowing astronomers to estimate distances to some of the millions of galaxies visible, and hence to make a three-dimensional map of the local universe. ... About APOD | ...

... This represents the first HI selected sample covering the core and the outskirts of a local cluster of galaxies. ... Optically selected samples miss a considerable number of low luminosity,