Present and Future Galaxy Redshift Surveys: ORS, DOGS and 2dF

TL;DR

This paper reviews three galaxy redshift surveys—ORS, DOGS, and 2dF—highlighting their methodologies, findings on large-scale structures like the Supergalactic Plane, and future prospects for mapping the universe's large-scale structure.

Contribution

It provides a comprehensive overview of recent and upcoming galaxy redshift surveys, including new analyses and techniques like neural networks for spectral classification.

Findings

Supergalactic Plane is at least as large as the survey (16000 km/sec).

Dwingeloo survey will systematically explore regions behind the Milky Way.

2dF survey aims to map large-scale structure with 250,000 redshifts.

Abstract

Three galaxy redshifts surveys and their analyses are discussed. (i) The recently completed Optical Redshift Survey (ORS) includes galaxies larger than 1.9 arcmin and/or brighter than $14.5^m$. It provides redshifts for $\sim 8300 $ galaxies at Galactic latitude $|b|>20^o$. A new analysis of the survey explores the existence and extent of the Supergalactic Plane (SGP). Its orientation is found to be in good agreement with the standard SGP coordinates, and suggests that the SGP is at least as large as the survey (16000 km/sec in diameter). (ii) The Dwingeloo Obscured Galaxy Survey is aimed at finding galaxies hidden behind the Milky-Way using a blind search in 21 cm. The discovery of Dwingeloo1 illustrates that the survey will allow us to systematically survey the region $30^o < l < 200^o$ out to 4000 km/sec. (iii) The Anglo-Australian 2-degree-Field (2dF) survey will yield 250,000 redshifts for APM-selected galaxies brighter than $19.5^m$ to map the large scale structure on scales larger than $\sim 30 \Mpc$. To study morphological segregation and biasing the spectra will be classified using Artificial Neural Networks.