It has been proposed that low surface brightness (LSB) galaxies may form in low density regions as a result of certain statistical properties of the density eld (Hooman et al. 1992). This idea is investigated with direct Hydrodynamical simulations, using a combined Smooth Particle Hydrodynamics (SPH) and gravitational tree method. It is found that although more mass is collected around a densit...

We recover the joint and individual space density and surface brightness distribution(s) of galaxies from the Millennium Galaxy Catalogue. The MGC is a local survey spanning 30.9 deg and probing approximately one–two mag arcsec deeper than either the TwoDegree Field Galaxy Redshift Survey (2dFGRS) or the Sloan Digital Sky Survey (SDSS). The MGC contains 10 095 galaxies to BMGC < 20 mag with 96 ...

Anomalously high K-band surface brightness fluctuations (SBF) have been reported in NGC 4489 by Pahre & Mould (1994), Jensen et al. (1996) and Jensen et al. (1998). However, these conclusions were uncertain because of relatively low signal-to-noise data. New high signal-to-noise data for NGC 4489 have been obtained at the NOAO/KPNO 2.1m and the ESO/La Silla 3.5m NTT telescopes. Adopting the I-b...

CCD – photometry is presented for 20 dIrr galaxies situated in the nearby complexes CenA/M83, and CVnI as well as in the general field of the Local Volume. We present integrated magnitudes of the galaxies in B, V, Ibands and also surface brightness profiles to a median isophote μB ∼ 28 mag sq. arcsec . The popular Sersic parameterization of surface brightness profiles generally does a poor job ...

An attempt is made to set constraints on the otherwise ambiguous decomposition of the rotation curves of low surface brightness galaxies into contributions due to the various components of the galaxies. For this purpose galaxies are selected which show clear spiral structure. Arguments of density wave theory of galactic spiral arms are then used to estimate the masses of the galactic disks. The...

[1] Since mineral aerosols absorb significant amounts of infrared radiation, they may contribute to errors in the retrievals of atmospheric and surface parameters from the TIROS Operational Vertical Sounder (TOVS) High-Resolution Infrared Radiation Sounder (HIRS) if the atmosphere is assumed clear. TOVS is an operational sounder on NOAA polar satellites. To see if observed brightness temperatur...

We used V and I CCD photometry to search for low-surface brightness dwarf galaxies in the central (< 0.5 h Mpc) region of the loose groups NGC 6868 (Telescopium) and NGC 5846, the compact group HCG 42 and the poor cluster IC 4765. We used the parameters given by the exponential profile fit (central surface brightness, scale length and limiting diameter) to identify 80 low surfacebrightness dwar...

We discuss the importance of digitised sky-limited Schmidt Band R-band, and H images of extended translucent (A B ' 1 ? 5 mag) and dark (A B > 5 mag) clouds. In translucent clouds (e.g. high-latitude cirrus) photons can penetrate through the whole cloud and control the physical and chemical processes. Comparison of the B images with far-infrared/submillimetre CO, C I], and C II] emission provid...

We compute surface brightness profiles of galactic disks for outwardly propagating waves of star formation with a view to investigate the stellar populations in ring galaxies. We consider two mechanisms which can create outwardly propagating star forming rings in a purely gaseous disk — a self-induced wave and a density wave. We show that the surface brightness profiles produced by both scenari...

We examine the effects on the Fundamental Plane (FP) of structural departures from an R galaxy light profile. We also explore the use of spatial (i.e. volumetric) as well as projected galaxy parameters. We fit the Sersic R law to the V-band light profiles of 26 E/S0 Virgo galaxies, where n is a shape parameter that allows for structural differences amongst the profiles. The galaxy light profile...