The Distribution of ALFALFA Galaxies

TL;DR

The ALFALFA survey aims to map the distribution of gas-rich galaxies in the local universe, providing new insights into galaxy populations, the HI mass function, and cosmological structures.

Contribution

This paper presents the first results from the ALFALFA survey, highlighting its improved sensitivity and scope for studying gas-rich galaxy distribution.

Findings

Preliminary distribution of local gas-rich galaxies.

Enhanced measurement of the HI mass function.

Potential for detailed cosmological analysis.

Abstract

The ALFALFA blind HI survey will enable a census of the distribution of gas-rich galaxies in the local Universe. Sensitive to an HI mass of 10**7 solar masses at the distance of the Virgo cluster, ALFALFA will probe the smallest objects locally and provide a new consideration of near-field cosmology. Additionally, with a larger, cosmologically significant sample volume and wider bandwidth than previous blind surveys, a much larger number of detections in each mass bin is possible, with adequate angular resolution to eliminate the need for extensive follow-up observations. This increased sensitivity will greatly enhance the utility of cosmological probles in HI. ALFALFA will eventually measure the correlation function of HI selected galaxies in a large local volume. The larger sample and volume size of the ALFALFA dataset will also robustly measure the HI mass function (HIMF). Here, we present the preliminary results on the distribution of local gas-rich galaxies from a first ALFALFA catalog covering 540 deg**2.