Reconstructing the Intrinsic Triaxial Shape of the Virgo Cluster

Bomee Lee; Jounghun Lee

Home/Archive/arXiv

arXiv · 0704.1400

Reconstructing the Intrinsic Triaxial Shape of the Virgo Cluster

Bomee Lee·Jounghun Lee

View original source ↗Read source document ↗Export metadata ↓

Abstract

To use galaxy clusters as a cosmological probe, it is important to account for their triaxiality. Assuming that the triaxial shapes of galaxy clusters are induced by the tidal interaction with the surrounding matter, Lee and Kang recently developed a reconstruction algorithm for the measurement of the axial ratio of a triaxial cluster. We examine the validity of this reconstruction algorithm by performing an observational test of it with the Virgo cluster as a target. We first modify the LK06 algorithm by incorporating the two dimensional projection effect. Then, we analyze the 1275 member galaxies from the Virgo Cluster Catalogue and find the projected direction of the Virgo cluster major axis by measuring the anisotropy in the spatial distribution of the member galaxies in the two dimensional projected plane. Applying the modified reconstruction algorithm to the analyzed data, we find that the axial ratio of the triaxial Virgo cluster is (1: 0.54 : 0.73). This result is consistent with the recent observational report from the Virgo Cluster Survey, proving the robustness of the reconstruction algorithm. It is also found that at the inner radii the shape tends to be more like prolate. We discuss the possible effect of the Virgo cluster triaxiality on the mass estimation.

Explore related subjects

astro-ph

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Bomee Lee, Jounghun Lee. 2007-04-11. Reconstructing the Intrinsic Triaxial Shape of the Virgo Cluster. https://arxiv.org/abs/0704.1400

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

The mildly nonlinear imprint of structure on the CMB: the $O(\ell)$ couplings are lensing and aberration

The exact 1+3 covariant multipole hierarchy for the CMB brightness contains kinematic couplings between the shear, acceleration and vorticity of the observers and the temperature multipoles, whose coefficients grow linearly in $\ell$. They are products of first-order quantities, so linearization about FLRW removes them. Here they are kept as sources in a weakly nonlinear extension of the almost-FLRW temperature anisotropies, and evaluated in the aligned-wavevector, weak-coupling limit. In the Newtonian frame the acceleration terms cancel at leading order in $1/\ell$. In the total (CDM) frame the shear terms cancel in the same way, to a residual of about $3/\ell$ of either term. Earlier versions of this paper reported that the total-frame terms do not cancel, and inferred a mildly nonlinear Rees-Sciama imprint near $\ell \sim 100 - 300$. That result came from a sign misprint in the $\ell-2$ shear coupling and is withdrawn; see the Note added. The $O(\ell)$ couplings are the multipole form of gravitational lensing and observer aberration, both already in the standard treatment. The explicit kinematic couplings written here are only part of the full second-order propagation source; the perturbed free-streaming contribution is linearized away in this paper.

astro-ph↗

arXiv2026

Cosmic Conundrums with Quantum Corrections

Darh energy was discovered over 25 years ago and we do not have an explanation of it. Dark matter comprises 95% of matter in the universe and we still don't know what it is. The Webb telescope has been finding fully formed galaxies with massive black holes millions of times the mass of the sun in the early universe and we don't have any explanation. A quantum density limitation will be used to solve these and other outstanding problems.

astro-ph↗

arXiv2026

On binary pulsars and the force of gravity

The energy-momentum budget of the astrophysical systems can be studied by the exact local conservation equation derived by Landau and Lifshitz. We show that a similar equation is valid for the Einstein-Cartan gravity. We reanalyze a binary pulsar system using the Landau-Lifshitz conservation equation and show that the orbital period change rate can be completely understood as a curvature backreaction process. Taking into account the detailed theoretical and observational research of relativistic binary pulsar systems, especially the system of Hulse and Taylor, we conclude that general relativity and astrophysical observations rule out the existence of gravitational radiation. We comment upon the LIGO GW events and their alternative explanation, as well as the recent pulsar timing arrays data.

astro-ph↗