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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 significance for correlations of the Lyman alpha absorption line wavelengths between different lines of sight over the whole redshift range. The significance rises to 3.2 sigma if we restrict the redshift range to 2.60 < z < 3.37, and to 4.0 sigma if we further restrict the sample to lines with rest equivalent width 0.1 <= W0/(A) < 0.9. We conclude that a significant fraction of the Lyman alpha forest arises in structures whose correlation length extends at least over 30 arcmin (~26/h comoving Mpc at z=2.6 for H0 = 100h km/s/Mpc, Omega=1.0, Lambda=0). We have also calculated the three dimensional two point correlation function for Lyman alpha absorbers; we do not detect any significant signal in the data. However, we note that line blending prevents us from detecting the signal produced by a 100% overdensity of Lyman alpha absorbers in simulated data. We find that the Lyman alpha forest redshift distribution provides a more sensitive test for such clustering than the three dimensional two point correlation function.
We present the first observations of foreground Lyman-$alpha$ forest absorption from high-redshift galaxies, targeting 24 star-forming galaxies (SFGs) with $zsim 2.3-2.8$ within a $5 times 15$ region of the COSMOS field. The transverse sightline sepa
The amplitude of fluctuations in the Ly-a forest on small spatial scales is sensitive to the temperature of the IGM and its spatial fluctuations. The temperature of the IGM and its spatial variations contain important information about hydrogen and h
This work presents a new physically-motivated supervised machine learning method, Hydro-BAM, to reproduce the three-dimensional Lyman-$alpha$ forest field in real and in redshift space learning from a reference hydrodynamic simulation, thereby saving
We present the analysis of a sample of the Ly-$alpha$ forest spectra of 152 quasars taken with the HST FOS. The Ly-$alpha$ lines show little evolution at $0<z<1.7$. We see a difference between the evolution indices for weak and strong lines.
We present the results of a high-spatial-resolution study of the line emission in a sample of z=3.1 Lyman-Alpha-Emitting Galaxies (LAEs) in the Extended Chandra Deep Field-South. Of the eight objects with coverage in our HST/WFPC2 narrow-band imaging