相关论文: Cosmic anisotropies from quasars: from polarizatio…

The non-Euclidean geometry of spacetime induces an anisotropy in the apparent correlation function of high-redshift quasars. This effect can constrain the cosmological constant \Lambda independent of any assumptions about evolution of…

Recently, it was shown, that the absence of circular polarization of visible light from quasars, severely constrains the interpretation of axion like particles (ALPs) as a solution for the generation of the linear polarization. Furthermore,…

A growing number of Milky Way globular clusters have been identified to possess a noticeable degree of solid-body rotation. For several clusters, the combination of stellar proper motions and radial velocities allows for 3-dimensional spin…

Multiple previous studies using several different probes have shown considerable evidence for the existence of cosmological-scale anisotropy and a Hubble-scale axis. One of the probes that show such evidence is the distribution of the…

Measuring the alignment of polarized radio sources requires comparing vectors at different locations on the sky, i.e. on a sphere. A test of alignment is derived herein. While both large scale and coordinate independent, the test avoids the…

The orientation-based unification model proposes that radio-loud quasars and radio galaxies are the same objects observed at different angles. A key prediction of this model is that the quasars are seen at smaller angles to the line of…

Hot big bang cosmology says nothing about the topology of the Universe. A topology-independent algorithm is presented which is complementary to that of Lehoucq et al. 1996 and which searches for evidence of multi-connectedness using…

In the currently popular orientation-based unified scheme, a radio galaxy appears as a quasar when its principal radio-axis happens to be oriented within a certain cone opening angle around the observer's line of sight. Due to geometrical…

We investigate the distribution of companion galaxies around quasars using {\em Hubble Space Telescope} ({\em HST}) Advanced Camera for Surveys Wide Field Camera (ACS/WFC) archival images. Our master sample contains 532 quasars which have…

Last year (2013) was more or less the 50th anniversary of the discovery of quasars. It is an interesting time to review what we know (and don't know) about them both empirically and theoretically. These compact sources involving line…

Quasar-galaxy associations, if they result from the effect of gravitational lensing by foreground galaxies, depend sensitively on the shape of the quasar number counts. Two kinds of quasar number-magnitude relations are predicted to produce…

The theory of galaxy formation posits a clear correlation between the spin of galaxies and the orientation of the elements of the large-scale structure of the Universe, particularly cosmic filaments. A substantial number of observational…

We have investigated the spatial distribution of quasars and its relationship with redshift by using the two-point correlation function, the variance of cell counts and the conditional density as a function of redshift. By comparing our…

We investigate the cross-correlation between astrometric and timing-residual observables for distant sources, such as pulsars and galaxies, and equivalent observables for nearby solar system bodies. Using the unified spin-weighted formalism…

We present total-intensity and linear-polarization observations made with the Very Large Array at $\lambda$20 and 6 cm of a representative sample of 42 radio galaxies and quasars selected from the Molonglo Complete Sample. The sources have…

The stochastic gravitational wave background for pulsar timing arrays is often modeled by a Gaussian ensemble which is isotropic and unpolarized. However, the Universe has a discrete set of polarized gravitational wave sources at specific…

Observational studies of galaxy isophotal shapes have shown that galaxy orientations are anisotropic: a galaxy's long axis tends to be oriented toward the center of its host. This radial alignment is seen across a wide range of scales, from…

In recent years, large radio surveys of Active Galactic Nuclei (AGNs), comprising millions of sources, have become available where one could investigate dipole asymmetries, assumedly arising due to a peculiar motion of the Solar system.…

The majority of bright distant quasars $(z {}^{>}_{\sim} 1)$ may form in massive mergers appearing in compact galaxy groups in/and young clusters. The expected tests are (i) large correlation signal for medium-$z$ QSOs $(1 < z < 2)$ and…

If the disappearance of the broad emission lines observed in changing-look quasars originates from the obscuration of the quasar core by dusty clouds moving in the torus, high linear optical polarization would be expected in those objects.…