Spectroscopically Confirmed Large-Scale Structures Associated to a z=0.83 Cluster

Abstract

(Abridged) We present a discovery of definitive large-scale structures around RXJ0152.7--1352 at z=0.83 based on spectroscopic redshifts. In our previous papers, we reported a photometric identification of the large-scale structures at z~0.8. A spectroscopic follow-up observation was carried out on 8 selected regions covering the most prominent structures to confirm their association to the main cluster. In six out of the eight fields, a well isolated peak is identified in the distribution of spectroscopic redshifts at or near the cluster redshift. This is strong evidence for the presence of large-scale structures associated to the main cluster at z=0.83. We then investigate stellar populations of galaxies in the structures. The composite spectra are constructed from a number of red member galaxies on the colour-magnitude sequence. We consider three representative environments -- cluster, group, and field. The ``cluster'' red galaxies do not show any sign of on-going or recent star formation activities and the passive evolution can naturally link them to the present-day red sequence galaxies in the Sloan Digital Sky Survey. In contrast, the red galaxies in ``groups'' and in the ``field'' tend to show signs of remaining and/or recent star formation activities characterized by weak [OII] emissions and/or strong H delta absorptions. Our current data seem to favour a scenario that star formation is truncated in a short time scale (<1Gyr). This would imply that galaxy-galaxy interactions are responsible for the truncation of star formation.

14 pages, 9 figures, accepted for publication in MNRAS

References in corpus (14)

• On the Fate of Gas Accreting at a Low Rate onto a Black Hole
• Grand Unification of Solutions of Accretion and Winds around Black Holes and Neutron Stars
• Two Different Long-term Behaviors in Black-Hole Candidates: Evidence for Two Accretion Flows?
• Zero Energy Rotating Accretion Flows near a Black Hole
• Simulation of Thick Accretion Disks with Standing Shocks by Smoothed Particle Hydrodynamics
• Smoothed Particle Hydrodynamics Confronts Theory: Formation of Standing Shocks in Accretion Disks and Winds Around Black Holes
• The Dynamics of the M87 Globular Cluster System
• The effect of cooling on time dependent behaviour of accretion flows around black holes
• On the Dynamics of Suddenly Heated Accretion Disks around Neutron Stars
• On the Azimuthal Stability of Shock Waves around Black Holes
• Radiatively driven electron-positron jets from two component accretion flows
• Detection of two-armed spiral shocks on the accretion disk of the eclipsing fast nova V1494 Aquilae
• Why Canonical Disks Cannot Produce Advection Dominated Flows
• Bending Instability of an Accretion Disc Around a Black Hole

Cited by in corpus (7)

• The Dependence of Star Formation Rates on Stellar Mass and Environment at z~0.8
• The Observations of Redshift Evolution in Large Scale Environments (ORELSE) Survey : I. The Survey Design and First Results on Cl 0023+0423 at z = 0.84 and RX J1821.6+6827 at z = 0.82
• Periodic massloss from viscous accretion flows around black holes
• Shock oscillation model for QPOs in stellar-mass and supermassive black holes
• A Wide-Field Study of the z~0.8 Cluster RX J0152.7-1357: the Role of Environment in the Formation of the Red-Sequence
• Satellite quenching was not important for z$\sim$1 clusters: most quenching occurred during infall
• The submillimetre view of massive clusters at z~0.8-1.6