ﻻ يوجد ملخص باللغة العربية
Metal absorption systems are products of star formation. They are believed to be associated with massive star forming galaxies, which have significantly enriched their surroundings. To test this idea with high column density CIV absorption systems at z~5.7, we study the projected distribution of galaxies and characterise the environment of CIV systems in two independent quasar lines-of-sight: J103027.01+052455.0 and J113717.73+354956.9. Using wide field photometry (~80x60h$^{-1}$ comoving Mpc), we select bright (Muv(1350AA)<-21.0 mag.) Lyman break galaxies (LBGs) at z~5.7 in a redshift slice Delta z~0.2 and we compare their projected distribution with z~5.7 narrow-band selected Lyman alpha emitters (LAEs, Delta z~0.08). We find that the CIV systems are located more than 10h$^{-1}$ projected comoving Mpc from the main concentrations of LBGs and no candidate is closer than ~5h$^{-1}$ projected comoving Mpc. In contrast, an excess of LAEs -lower mass galaxies- is found on scales of ~10h$^{-1}$ comoving Mpc, suggesting that LAEs are the primary candidates for the source of the CIV systems. Furthermore, the closest object to the system in the field J1030+0524 is a faint LAE at a projected distance of 212h$^{-1}$ physical kpc. However, this work cannot rule out undiscovered lower mass galaxies as the origin of these absorption systems. We conclude that, in contrast with lower redshift examples (z<3.5), strong CIV absorption systems at z~5.7 trace low-to-intermediate density environments dominated by low-mass galaxies. Moreover, the excess of LAEs associated with high levels of ionizing flux agrees with the idea that faint galaxies dominate the ionizing photon budget at this redshift.
We present a theoretical model to predict the properties of an observed $z =$ 5.72 Lyman $alpha$ emitter galaxy - CIV absorption pair separated by 1384 comoving kpc/h. We use the separation of the pair and an outflow velocity/time travelling argument
We explore the properties of the large-scale environment of FR0 radio galaxies belonging to the FR0CAT sample which includes 104 compact radio sources associated with nearby (z<0.05) early-type galaxies. By using various estimators we find that FR0s
We present spectroscopic identification of 32 new quasars and luminous galaxies discovered at 5.7 < z < 6.8. This is the second in a series of papers presenting the results of the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project,
The alignment between satellites and central galaxies has been studied in detail both in observational and theoretical works. The widely accepted fact is that the satellites preferentially reside along the major axis of their central galaxy. However,
We study the spatial distribution of faint satellites of intermediate redshift (0.1<z<0.8), early-type galaxies, selected from the GOODS fields. We combine high resolution HST images and state-of-the-art host subtraction techniques to detect satellit