The Arecibo Galaxy Environments survey IV: the NGC7448 region and the HI mass function

Details The Arecibo Galaxy Environments survey IV: the NGC7448 region and the HI mass function The Arecibo Galaxy Environments survey IV: the NGC7448 region and the HI mass function

2011-04-04

arxiv.org/abs/1104.0507v1

Astronomy and Astrophysics

Astrophysics

Cosmology and Extragalactic Astrophysics

Scientific paper

In this paper we describe results from the Arecibo Galaxy Environments Survey (AGES). The survey reaches column densities of ~3x10^18 cm^-2 and masses of ~10^7 M_O, over individual regions of order 10 sq deg in size, out to a maximum velocity of 18,000 km s^-1. Each surveyed region is centred on a nearby galaxy, group or cluster, in this instance the NGC7448 group. Galaxy interactions in the NGC7448 group reveal themselves through the identification of tidal tails and bridges. We find ~2.5 times more atomic gas in the inter-galactic medium than in the group galaxies. We identify five new dwarf galaxies, two of which appear to be members of the NGC7448 group. This is too few, by roughly an order of magnitude, dwarf galaxies to reconcile observation with theoretical predictions of galaxy formation models. If they had observed this region of sky previous wide area blind HI surveys, HIPASS and ALFALFA, would have detected only 5% and 43% respectively of the galaxies we detect, missing a large fraction of the atomic gas in this volume. We combine the data from this paper with that from our other AGES papers (370 galaxies) to derive a HI mass function with the following Schechter function parameters alpha=-1.52+/-0.05, M^*=5.1+/-0.3x10^9 h_72^-2 M_O, phi=8.6+/-1.1x10-3 h_72^3 Mpc^-3 dex-1. Integrating the mass function leads to a cosmic mass density of atomic hydrogen of Omega_HI=5.3+/-0.8x10^-4 h_72^-1. Our mass function is steeper than that found by both HIPASS and ALFALFA (alpha=1.37 and 1.33 respectively), while our cosmic mass density is consistent with ALFALFA, but 1.7 times larger than found by HIPASS.

Affiliated with

Also associated with

No associations

Rating

The Arecibo Galaxy Environments survey IV: the NGC7448 region and the HI mass function does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with The Arecibo Galaxy Environments survey IV: the NGC7448 region and the HI mass function, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Arecibo Galaxy Environments survey IV: the NGC7448 region and the HI mass function will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-317591