The power spectrum of the flux distribution in the Lyman α forest of a large sample of UVES QSO absorption spectra (LUQAS)
Abstract
The flux power spectra of the Lyman α forest from a sample of 27 quasi-stellar objects (QSOs) taken with the high-resolution Ultraviolet Echelle Spectrograph (UVES) on the Very Large Telescope (VLT) are presented. We find a similar fluctuation amplitude at the peak of the `3D' flux power spectrum at k~ 0.03 s km-1 as the study by Croft et al. (2002), in the same redshift range. The amplitude of the flux power spectrum increases with decreasing redshift if corrected for the increase in the mean flux level as expected if the evolution of the flux power spectrum is sensitive to the gravitational growth of matter density fluctuations. This is in agreement with the findings of McDonald et al. (2000) at larger redshift. The logarithmic slope of the `3D' flux power spectrum, PF(k), at large scales k < 0.03 s km-1, is 1.4 +/- 0.3, i.e. 0.3 shallower than that found by Croft et al. but consistent within the errors.
Based on data taken from the ESO archive obtained with UVES at VLT, Paranal, Chile.- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 2004
- DOI:
- 10.1111/j.1365-2966.2004.07221.x
- arXiv:
- arXiv:astro-ph/0308103
- Bibcode:
- 2004MNRAS.347..355K
- Keywords:
-
- intergalactic medium;
- quasars: absorption lines;
- large-scale structure of Universe;
- Astrophysics
- E-Print:
- 18 pages, 9 PS figures, 6 tables. Note that the k-values of the 1D flux power spectrum had been erroneously shifted by half a bin size (in log k) in the previous version. All the other results are unaffected. New tables can be found at http://www.ast.cam.ac.uk/~rtnigm/luqas.htm