The radiative properties of interstellar dust are affected not only by the grain size distribution but also porosity. We develop a model for evolution size-dependent porosity and over entire history galaxy evolution. include stellar production, supernova destruction, shattering, coagulation, accretion. Coagulation is {assumed to be} source use one-zone with constant dense gas fraction ($\eta_\m...

Galaxy sizes correlate closely with the of their parent dark matter haloes, suggesting a link between halo formation and galaxy growth. However, precise nature this relation its scatter remains to be understood fully, especially for low-mass galaxies. We analyse galaxy-halo size ($M_\star \sim 10^{7-9} {\rm M_\odot}$) central galaxies over past 12.5 billion years help cosmological volume simula...

Lyman-break galaxies (LBGs) contain a non-negligible amount of dust. Takeuchi et al. (2003a) (T03) constructed a model of the infrared spectral energy distribution (SED) for very young galaxies by taking into account the dust size distribution in the early stage of galaxy evolution, which can be different from that of present-day evolved galaxies. We applied T03 model to LBGs and constructed th...

We use the Hubble Ultra Deep Field (UDF) to study the galaxy luminosity-size (M-R e) distribution. With a careful analysis of selection effects due to both detection completeness and measurement reliability we identify bias-free regions in the M-R e plane for a series of volume-limited samples. We also investigate the colour-log(n) distribution of these galaxies and further subdivide our data b...

From a classical point of view, there are no arguments capable of completely explaining the stability and the size of galaxies: the only assumption is that they are considered to be relaxed (and virialized) systems where gravity is the overall interaction [1]. Such a force is considered as a “Newtonian” interaction and the confining potentials, due to the mutual attractions of stars (and the ot...

We present WSRT observations of the neutral hydrogen in the nearby radio galaxy B2 0648+27. In emission, we detect a very large amount of H I (MHI = 1.1 · 10 10 M⊙) that is distributed in a very extended disk, or ring-like structure, of about 160 kpc in size. We also detect H I absorption against the central radio continuum component. The detection of the H I, its structure and kinematics, give...

We have modelled 38 barred galaxies by using near-IR and optical data from the Ohio State University Bright Spiral Galaxy Survey. We constructed the gravitational potentials of the galaxies from H-band photometry, assuming constant mass-to-light ratio. The halo component we chose corresponds to the so called universal rotation curve. In each case, we used the response of gaseous and stellar par...

Number counts of galaxies are re-analyzed using a semi-analytic model (SAM) of galaxy formation based on the hierarchical clustering scenario. Faint galaxies in the Subaru Deep Field (SDF, near-infrared J and K) and the Hubble Deep Field (HDF, ultraviolet/optical U , B, V , and I) are compared with our model galaxies. We have determined the astrophysical parameters in the SAM that reproduce obs...

It is difficult to detect X-ray emission associated with galaxies in rich clusters because the X-ray images of the clusters are dominated by the emission from their hot intracluster media (ICM). Only the nearby Virgo cluster provides us with information about the X-ray properties of galaxies in clusters. Here we report on the analysis of a deep ROSAT HRI image of the moderately-rich cluster, Ab...