Related papers: Structure in the Lyman-Alpha Forest
The spatial distribution of Ly-alpha forest absorption systems towards ten QSOs has been analysed to search for large-scale structure over the redshift range 2.2 < z < 3.4. The QSOs form a closely spaced group on the sky and are…
We present results from a survey of the Lyman alpha forest at 2.15<z<3.26 toward ten QSOs concentrated within a 1 degree field. We find correlations of the Lyman alpha absorption line wavelengths between different lines-of-sight over the…
We present a new technique for detecting structure on Mpc scales in the Lyman-alpha forest. The technique is easy to apply in practice since it does not involve absorption line fitting but is rather based on the statistics of the…
We present a search for spatial and redshift correlations in a 2 A resolution spectroscopic survey of the Lyman alpha forest at 2.15 < z < 3.37 toward ten QSOs concentrated within a 1-degree diameter field. We find a signal at 2.7 sigma…
We present an analysis of the non-Gaussianity in the distribution of Ly$\alpha$ forest lines in the QSO absorption spectra. Statistical tests performed on this data indicate that there may be large scale structure even though the power…
We study the clustering of matter in the intergalactic medium from the Lyman-alpha forests seen in the spectra of pairs or groups of z ~ 2 quasars observed with FORS2 and UVES at the VLT-UT2 Kueyen ESO telescope. The sample consists of five…
The spatial distribution of the Ly$\alpha$ forest is studied using new HST data for the quasar pair Q~1026--0045 A and B at $z_{em}$ = 1.438 and 1.520 respectively. The angular separation is 36 arcsec and corresponds to transverse linear…
Observations of redshifted Lyman alpha forest absorption in the spectra of quasistellar objects (QSOs) provide a highly sensitive probe of the distribution of gaseous matter in the universe. Over the past two decades optical spectroscopy…
We present the first observations of foreground Lyman-$\alpha$ forest absorption from high-redshift galaxies, targeting 24 star-forming galaxies (SFGs) with $z\sim 2.3-2.8$ within a $5' \times 15'$ region of the COSMOS field. The transverse…
Probing the size and shape of the absorbers that lie in front of the QSOs, in particular the Ly alpha forest, we analyze 785 absorption lines in spectra of five QSOs in close groupings: a pair and a triplet. Both QSO groups have been…
A wavelet space-scale decomposition (SSD) analysis of large scale structures in the universe has been developed. The SSD method of identifying and measuring structures in the spatial distribution of objects has been demonstrated. The…
The low-redshift Ly-alpha forest of absorption lines provides a probe of large-scale baryonic structures in the intergalactic medium, some of which may be remnants of physical conditions set up during the epoch of galaxy formation. We…
We present results on the evolution and clustering of Ly-alpha lines at low z. The sample contains 1298 Ly-alpha lines from 165 quasar spectra mined from the archives of the HST/FOS. Our sample extends to z=1.7, slightly higher than the…
We have conducted pointed redshift surveys for galaxies in the direction of bright AGN whose HST far-UV spectra contain nearby (cz <~ 30,000 kms), low column density (12.5 <= log N_{HI} (cm s^{-2}) <= 14.5) Ly-alpha forest absorption…
Cosmological simulations with gas provide a detailed description of the intergalactic medium, making possible predictions of neutral hydrogen absorption in the spectra of background QSOs. We present results from a high-resolution…
Spectra of the QSO pair Q0307-195A,B have been obtained in the Ly-alpha Forest (3660 - 3930 A) and C IV (4720 - 4850 A) regions with a FWHM resolution between 0.7 and 0.5 A. 46 lines have been detected in the spectrum of object A while 36…
We describe a robust Bayesian statistical method for determining Lyman alpha forest cloud sizes in spherical and in thin disk geometries, using absorption in adjacent sightlines toward closely separated QSO pairs and groups, apply this…
Combining a new, increased dataset of 8 QSOs covering the Ly-alpha forest at redshifts 1.5 < z < 3.6 from VLT/UVES observations with previously published results, we have investigated the properties of the Ly-alpha forest at 1.5 < z < 4. We…
Straightforward physical arguments are used to derive the properties of Lyman-alpha forest absorbers. It is shown that many aspects of the current physical picture of the forest, in particular the fact that the absorption arises in extended…
Higher order clustering statistics of Ly$\alpha$ forest provide a unique probe to study non-gaussianity in Intergalactic matter distribution up to high redshifts and from large to small scales. The author presents a brief review of his work…