Related papers: Resolving the Lyman-alpha Forest
We measure the amount of absorption in the Lyman-alpha forest at 0 < z < 1.6 in HST FOS spectra of 74 QSOs. At 0 < z < 1.6 we find that 79% of the absorption is from the low density intergalactic medium, 12% from metals and 9% from the…
We have analyzed the properties of low column density Lyman alpha forest clouds (12.8 < log N_HI < 16.0) toward 5 QSOs at different redshifts, using high signal-to-noise data from the HIRES spectrograph on the Keck I 10-m telescope. The…
During September 2023 the Alice ultraviolet spectrograph on the New Horizons (NH) spacecraft was used to map diffuse Lyman alpha (Lya) emission over most of the sky, at a range of 56.9 AU from the Sun. At that distance, models predict that…
We study the effect of galactic outflows on the Lya forest. The winds are modelled as fully ionised spherical bubbles centered around galactic haloes. The observed flux probability distribution and flux power spectrum limit the volume…
The angular positions of quasars are deflected by the gravitational lensing effect of foreground matter. The Lyman-alpha forest seen in the spectra of these quasars is therefore also lensed. We propose that the signature of weak…
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…
Using high resolution (R ~ 45000), high S/N (20-50) VLT/UVES observations covering the Lyman-alpha forest at 1.5 < z < 2.4 combined with similar observations at z > 2.4 from the literature, we have presented the redshift evolution of the…
The evolution of the temperature in the intergalactic medium is related to the reionization of hydrogen and helium, and has important consequences for our understanding of the Lya forest and of galaxy formation in gravitational models of…
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…
The Lyman-$\alpha$ absorption spectrum associated with photons traversing the intergalactic medium allows us to probe the linear matter power spectrum down to relatively small distance scales. Finding ways of accurately evaluating…
Using our 3D Lya radiation transfer code, we compute the radiation transfer of Lya and UV continuum photons including dust. Observational constraints on the neutral gas (column density, kinematics, etc.) are taken from other analysis of…
Estimates of the metagalactic hydrogen ionization rate from the Lyman-alpha forest opacity in QSO absorption spectra depend on the complex density distribution of neutral hydrogen along the line-of-sight. We use a large suite of high…
We consider possible observational consequences of dust and metals in \lya forest clouds. We relate the dust content, $\Omega_d^{Lya}$, to the metal evolution of the absorbers and assume that dust is heated by the ultraviolet background…
We study of the properties of a new class of circumgalactic medium absorbers identified in the Lyman-$\alpha$ forest: "Strong, Blended Lyman-$\alpha$" (or SBLA) absorption systems. We study SBLAs at $2.4<z<3.1$ in SDSS-IV/eBOSS spectra by…
We propose a simple model for the origin and evolution of \lya clouds based on cosmological conductive/cooling fronts. In this model the \lya arises in the interfaces between the IGM and cold clouds that could be tentatively identified with…
We present LyMAS2, an improved version of the "Lyman-{\alpha} Mass Association Scheme" aiming at predicting the large-scale 3d clustering statistics of the Lyman-{\alpha} forest (Ly-{\alpha}) from moderate resolution simulations of the dark…
We present the first measurement of the large-scale cross-correlation of Lyman alpha forest absorption and Damped Lyman alpha systems (DLA), using the 9th Data Release of the Baryon Oscillation Spectroscopic Survey (BOSS). The…
We present some statistical features of the large number of \lya absorption lines detected in high redshift quasar spectra, obtained by using the multifractal approach. In the analysed sample of 12 QSO sight--lines, 11 show scaling…
The Lyman-alpha forest is a unique probe of large-scale matter density fluctuations at high redshift (z > 2). It is possible to obtain 3D maps of the matter distribution from Lyman-alpha data, using tomographic reconstruction methods. Here,…
We use a cosmological hydrodynamic simulation of a cold dark matter universe to investigate theoretically the relationship between high redshift galaxies and the Lyman=alpha forest at redshift z=3. Galaxies in the simulation are surrounded…