Search results for "Velocity"
showing 10 items of 881 documents
The X-ray Luminosity - Velocity Dispersion relation in the REFLEX Cluster Survey
2003
We present an estimate of the bolometric X-ray luminosity - velocity dispersion L_x - sigma_v relation measured from a new, large and homogeneous sample of 171 low redshift, X-ray selected galaxy clusters. The linear fitting of log(L_x) - log(sigma_v) gives L_x = 10^{32.72 \pm 0.08} sigma^{4.1 \pm 0.3}_v erg s^{-1} h^{-2}_{50}. Furthermore, a study of 54 clusters, for which the X-ray temperature of the intracluster medium T is available, allows us to explore two other scaling relations, L_x -T and sigma_v -T. From this sample we obtain L_x \propto T^{3.1 \pm 0.2} and sigma_v \propto T^{1.00 \pm 0.16}, which are fully consistent with the above result for the L_x-sigma_v. The slopes of L_x -T…
Redshifts of southern clusters. II
1991
New redshifts are given for 21 clusters of galaxies from the Abell, Corwin, and Olowin Rich Cluster Catalogue. The redshift of the brightest cluster galaxy - where the brightest member is brighter than 15.5 - is employed as an indicator of the mean cluster redshift. The redshifts of first-, second-, and third-ranked galaxies are shown to agree, confirming the value of the survey procedure, although some clusters require more information than simply the redshift of the brightest cluster. 7 refs.
Inelastic scattering and interactions of three-wave parametric solitons.
2006
We study the interactions of velocity-locked three-wave parametric solitons in a medium with quadratic nonlinearity and dispersion. We reveal that the inelastic scattering between three-wave solitons and linear waves may be described in terms of analytical solutions with dynamically varying group velocity, or boomerons. Moreover, we demonstrate the elastic nature of three-wave soliton-soliton collisions and interactions.
Dark-and-bright rogue waves in long wave-short wave resonance
2014
Nonlinear Photonics, Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, in Proceedings Advanced Photonics, Part of Advanced Photonics, Barcelona, Spain, 28-31 July 2014
Phenomenological description of counterflow superfluid turbulence in rotating containers
2004
In this paper a simple equation for the vortex line density describing some of the most relevant observed effects in counterflow superfluid turbulence in ${}^{4}\mathrm{He}$ in the presence of rotation is proposed. This model is based on a generalization of Vinen's equation which incorporates as additional quantity the angular velocity \ensuremath{\Omega}.
Nonlinear interaction of light with Bose-Einstein condensate: new methods to generate subpoissonian light
2004
We consider $\Lambda$-type model of the Bose-Einstein condensate of sodium atoms interacting with the light. Coefficients of the Kerr-nonlinearity in the condensate can achieve large and negative values providing the possibility for effective control of group velocity and dispersion of the probe pulse. We find a regime when the observation of the "slow" and "fast" light propagating without absorption becomes achievable due to strong nonlinearity. An effective two-level quantum model of the system is derived and studied based on the su(2) polynomial deformation approach. We propose an efficient way for generation of subpoissonian fields in the Bose-Einstein condensate at time-scales much sho…
Relaxation of the field-induced structural anisotropy in a rotating magnetic fluid
2009
The relaxation of field-induced anisotropy in a magnetic fluid with dominant repulsion is theoretically modeled and experimentally measured by small angle neutron scattering on a sample rotating at angular velocity ω. The scattered pattern distortion scales as the Mason number Mn=ω·τq, τq being the q-dependent diffusion time of nanoparticles. The model accounts for the magnetophoretical drift in the non-homogeneous self-magnetic field of the assembly, continuously created by the thermal noise. The Mn-dependence of the pattern distortion is well described without any adjustable parameter.
Monte Carlo Simulation of Electron Dynamics in Doped Semiconductors Driven by Electric Fields: Harmonic Generation, Hot-Carrier Noise and Spin Relaxa…
2011
In solid state electronics the miniaturization of integrated circuits implies that, even at moderate applied voltages, the components can be exposed to very intense electric fields. Advances in electronics push the devices to operate also under cyclostationary conditions, i.e. under large-signal and time-periodic conditions. A main consequence of this fact is that circuits exhibit a strongly nonlinear behavior. Furthermore, semiconductor based devices are always imbedded into a noisy environment that could strongly affect their performance, setting the lower limit for signal detection in electronic circuits. For this reason, to fully understand the complex scenario of the nonlinear phenomen…
Radiation resonant transmission and reflection by a thin layer of an anisotropic plasma
2005
The possibility of radiation resonant transmission and reflection by a thin layer of a plasma possessing an anisotropic electron velocity distribution strongly elongated in the direction of the incident wave polarization is established.
The imprints of the Great Attractor and the Virgo cluster on the microwave background
1993
A fully non-linear model based on the Tolman-Bondi solution of the Einstein equations is used to describe the Great Attractor and the Virgo cluster. The background is a Friedmann-Robertson-Walker universe, and the inhomogeneity develops from physically motivated initial profiles of the energy density and the peculiar velocity. Accurate numerical integrations of the field equations of the null geodesics are carried out, and thus the angular temperature distribution of the microwave background produced by the chosen overdensities is found. The observer is located in the Local Group. The quadrupole Q produced by each overdensity is computed and divided into two parts: the relativistic Doppler …