Astronomy and Astrophysics – Astronomy
Scientific paper
Aug 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008mnras.388.1889w&link_type=abstract
Monthly Notices of the Royal Astronomical Society, Volume 388, Issue 4, pp. 1889-1898.
Astronomy and Astrophysics
Astronomy
6
Galaxies: High-Redshift, Intergalactic Medium, Cosmology: Theory, Diffuse Radiation, Large-Scale Structure Of Universe
Scientific paper
Observations of damped Lyα absorbers (DLAs) indicate that the fraction of hydrogen in its neutral form (HI) is significant by mass at all redshifts. This gas represents the reservoir of material that is available for star formation at late times. As a result, observational identification of the systems in which this neutral hydrogen resides is an important missing ingredient in models of galaxy formation. Precise identification of DLA host mass via traditional clustering studies is not practical owing to the small numbers of known systems being spread across sparsely distributed sightlines. However, following the completion of re-ionization, 21-cm surface brightness fluctuations will be dominated by neutral hydrogen in DLAs. No individual DLAs could be detected in 21-cm emission. Rather, observations of these fluctuations will measure the combined clustering signal from all DLAs within a large volume. We show that measurement of the spherically averaged power spectrum of 21-cm intensity fluctuations due to DLAs could be used to measure the galaxy bias for DLA host galaxies when combined with an independent measurement of the cosmological HI mass density from quasar absorption studies. Utilizing this technique, the low-frequency arrays now under construction could measure the characteristic DLA host mass with a statistical precision as low as 0.3dex at z >~ 4. In addition, high signal-to-noise ratio observations of the peculiar-motion-induced anisotropy of the power spectrum would facilitate measurement of both the DLA host mass and the cosmic HI density directly from 21-cm fluctuations. By exploiting this anisotropy, a second generation of low-frequency arrays with an order of magnitude increase in collecting area could measure the values of cosmic HI density and DLA host mass, with uncertainties of a few per cent and a few tens of per cent, respectively.
No associations
LandOfFree
A method to measure the mass of damped Lyα absorber host galaxies using fluctuations in 21-cm emission 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 A method to measure the mass of damped Lyα absorber host galaxies using fluctuations in 21-cm emission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A method to measure the mass of damped Lyα absorber host galaxies using fluctuations in 21-cm emission will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1798116