相关论文: The analytic radial acceleration relation for gala…
The discovery that the cosmic expansion is accelerating has been followed by an intense theoretical and experimental response in physics and astronomy. The discovery implies that our most basic notions about how gravity work are violated on…
The interaction of magnetic turbulence and relativistic particles is a important process for understanding particles propagation and acceleration in many astrophysical environments. Large-scale turbulence can be generated in the…
It appears that the dynamical status of clusters and groups of galaxies is related to the large-scale structure of the Universe. A few interesting trends have been established: (1) The Cluster Substructure - Alignment Connection, by which…
The dark matter (DM) haloes around spiral galaxies appear to conspire with their baryonic content: empirically, significant amounts of DM are inferred only below a universal characteristic acceleration scale. Moreover, the discrepancy…
We study the radial acceleration relation (RAR) for early-type galaxies (ETGs) in the SDSS MaNGA MPL5 dataset. The complete ETG sample show a slightly offset RAR from the relation reported by McGaugh et al. (2016) at the low-acceleration…
Radio observations prove the existence of relativistic particles and magnetic field associated with the intra-cluster-medium (ICM) through the presence of extended synchrotron emission in the form of radio halos and peripheral relics. This…
Based on thermodynamics, we discuss the galactic clustering of expanding Universe by assuming the gravitational interaction through the modified Newton's potential given by $f(R)$ gravity. We compute the corrected $N$-particle partition…
We derive a formula for the velocity distribution of an axially symmetric galaxy where the mass density is corrected using the mass formula from special relativity. We take some reasonable test mass densities and numerically compute the…
A brief review of various methods to calculate radiative accelerations for stellar evolution and an analysis of their limitations are followed by applications to Pop I and Pop II stars. Recent applications to Horizontal Branch (HB) star…
The dark matter halo surface density, given by the product of the dark matter core radius ($r_c$) and core density ($\rho_c$) has been shown to be a constant for a wide range of isolated galaxy systems. Here, we carry out a test of this…
We investigate the interplay of cosmic ray (CR) propagation and advection in galaxy clusters. Propagation in form of CR diffusion and streaming tends to drive the CR radial profiles towards being flat, with equal CR number density…
A geometric theory for spacetimes whose world lines associated with physical particles have an upper bound for the proper acceleration is developed. After some fundamental remarks on the requirements that the classical dynamics for point…
We estimate the number of individual, fast-moving stars observable in globular clusters under the assumption that the clusters contain massive central black holes which follow the galactic black-hole mass vs. sigma relationship. We find…
We show that an expected number ratio of radial arcs (gravitationally lensed images whose major axes lie in the radial direction of a cluster-lens potential) to tangential arcs (gravitationally lensed images whose major axes lie in the…
The acceleration of electrons at shock fronts is thought to be responsible for radio relics, extended radio features in the vicinity of merging galaxy clusters. By combining high resolution Adaptive Mesh Refinement Hydro/N-body cosmological…
The dependence of the cosmic ray intensity on Galactocentric distance is known to be much less rapid than that to be thought-to-be sources: supernova remnants. This is an old problem ('the radial gradient problem') which has led to a number…
In a disc galaxy the distribution of azimuthal components of velocity is very skew. In the past this skewness has been modelled by superposed Gaussians. We use dynamical arguments to derive an analytic formula that can be fitted to observed…
The observed rotation curves of disc galaxies, ranging from late-type dwarf galaxies to early-type spirals, can be fit remarkably well simply by scaling up the contributions of the stellar and HI discs. This `baryonic scaling model' can…
Milgrom's modified Newtonian dynamics (MOND) can explain well the mass discrepancy problem in galaxy without invoking dark matter. The MOND theory predicts a universal constant acceleration scale in galaxy, below which the Newtonian…
Dynamical evolution of stellar mass distribution in star clusters is analysed by considering simultaneously the effects of dynamical friction, stochastic heating and the gravitational potential due to mass distribution in the clusters. A…