Over half of GeV gamma-ray sources observed by the EGRET experiment have not yet been identified as known astronomical objects. There is an isotropic component of such unidentified sources, whose number is about 60 in the whole sky. Here we calculate the expected number of dynamically forming clusters of galaxies emitting gamma-rays by high energy electrons accelerated in the shock wave when th...

In conjunction with the Australian Government’s Spectrum Management Agency, experimental tests have been carried out to determine the susceptibility of the Molonglo Observatory Synthesis Telescope (MOST) to interference from terrestrial transmitters. The motivation for the tests was to reconcile the conflicting requirements of the MOST, which is committed to an extensive survey of the southern ...

We present, using a novel technique, a study of the angular distribution of satellite galaxies around a sample of isolated, blue host galaxies selected from the sixth data release of the Sloan Digital Sky Survey. As a complement to previous studies we subdivide the sample of galaxies into bins of differing inclination and use the systematic differences that would exist between the different bin...

We study the spatial distribution of satellite galaxies by assuming that they follow the dark matter distribution. This assumption is supported by semi-analytical studies based on high-resolution numerical simulations. We find that for a Milky-Way type halo, if only a dozen satellite galaxies are observed, then they can lie on a “great” disk with an rms height of about 40 kpc. The normal to the...

We discuss interpretation of the cosmic infrared background (CIB) anisotropies detected by us recently in the Spitzer IRAC based measurements. The fluctuations are approximately isotropic on the sky consistent with their cosmological origin. They remain after removal of fairly faint intervening sources and must arise from a population which has a strong CIB clustering component with only a smal...

We present results of random simulations for the expected isotropic distributions of the polar and azimuthal angles of galaxy rotation axes. It is found that selection effects concerning position and inclination of galaxies can remarkably change the shape of these distributions. Selection effects of this kind may play an important role when galaxies are taken from an incomplete dataset (e.g. fr...

A search for water masers in 47 Sloan Digital Sky Survey Type 2 quasars using the Green Bank Telescope has yielded a detection at a redshift of z = 0.660. This maser is more than an order of magnitude higher in redshift than any previously known and, with a total isotropic luminosity of 23,000 L⊙, also the most powerful. The presence and detectability of water masers in quasars at z ∼ 0.3− 0.8 ...

A search for water masers in 47 Sloan Digital Sky Survey Type 2 quasars using the Green Bank Telescope has yielded a detection at a redshift of z = 0.660. This maser is more than an order of magnitude higher in redshift than any previously known and, with a total isotropic luminosity of 23,000 L⊙, also the most powerful. The presence and detectability of water masers in quasars at z ∼ 0.3− 0.8 ...

We propose a detection technique in 2D images based on an isotropic wavelet family. This family is naturally constructed as an extension of the GaussianMexican Hat Wavelet pair and for that reason we call it the Mexican Hat Wavelet Family (MHWF). We show the performance of these wavelets for dealing with the detection of point extragalactic sources in cosmic microwave background (CMB) maps: a v...

This article is concerned primarily with the intrinsic anisotropy in the angular distribution of 2281 gamma-ray bursts (GRBs) collected in Current BATSE Gamma-Ray Burst Catalog until the end of year 1998, and, second, with intrinsic anisotropies of three subclasses (”short”, ”intermediate”, ”long”) of GRBs. Testing based on spherical harmonics of each class, in equatorial coordinates, is presen...