The extent of the Mg II absorbing circumgalactic medium of quasars

We investigate the extent and the properties of the Mg II cool, low-density absorbing gas located in the halo and in the circumgalactic environment of quasars, using a sample of 31 projected quasar pairs with impact parameter pd &lt; 200 kpc in the redshift range 0.5 ≲ z ≲ 1.6. In the transverse direction, we detect 18 Mg II absorbers associated with the foreground quasars, while no absorption system originated by the gas surrounding the quasar itself is found along the line of sight. This suggests that the quasar emission induces an anisotropy in the absorbing gas distribution. Our observations indicate that the covering fraction (fC) of Mg II absorption systems with rest-frame equivalent width Wr(&lambda;2796) &gt; 0.3 &Aring; ranges from fC &tilde; 1.0 at pd ≲ 65 kpc to fC &tilde; 0.2 at pd ≳ 150 kpc, and appears to be higher than that for galaxies. Our findings support a scenario where the luminosity/mass of the host galaxies affect the extent and the richness of the absorbing Mg II circumgalactic medium.</p

Bright [C II] 158 μm Emission in a Quasar Host Galaxy at z = 6.54

The [C ii] 158 μm fine-structure line is known to trace regions of active star formation and is the main coolant of the cold, neutral atomic medium. In this Letter, we report a strong detection of the [C ii] line in the host galaxy of the brightest quasar known at z\gt 6.5, the Pan-STARRS1 selected quasar PSO J036.5078+03.0498 (hereafter P036+03), using the IRAM NOEMA millimeter interferometer. Its [C ii] and total far-infrared luminosities are (5.8+/- 0.7)× {{10}9} {{L}☉ } and (7.6+/- 1.5)× {{10}12} {{L}☉ }, respectively. This results in an {{L}[C II]}/{{L}TIR} ratio of ∼ 0.8× {{10}-3}, which is at the high end of those found for active galaxies, though it is lower than the average found in typical main-sequence galaxies at z∼ 0. We also report a tentative additional line that we identify as a blended emission from the {{3}22}-{{3}13} and {{5}23}-{{4}32} H2O transitions. If confirmed, this would be the most distant detection of water emission to date. P036+03 rivals the current prototypical luminous J1148+5251 quasar at z = 6.42, in both rest-frame UV and [C ii] luminosities. Given its brightness and because it is visible from both hemispheres (unlike J1148+5251), P036+03 has the potential of becoming an important laboratory for the study of star formation and of the interstellar medium only ∼800 Myr after the Big Bang. Based on observations carried out under project number E14AG with the IRAM NOEMA Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain)

No Overdensity of Lyman-Alpha Emitting Galaxies around a Quasar at z ̃ 5.7

Bright quasars, observed when the universe was less than one billion years old (z > 5.5), are known to host massive black holes (̃109 M☉) and are thought to reside in the center of massive dark matter overdensities. In this picture, overdensities of galaxies are expected around high-redshift quasars. However, observations based on the detection of Lyman-break galaxies (LBGs) around these quasars do not offer a clear picture: this may be due to the uncertain redshift constraints of LBGs, which are solely selected through broadband filters. To circumvent such uncertainties, we here perform a search for Lyman-alpha emitting galaxies (LAEs) in the field of the quasar PSO J215.1512-16.0417 at z ̃ 5.73, through narrowband deep imaging with FORS2 at the Very Large Telescope. We study an area of 37 arcmin2, I.e., ̃206 comoving Mpc2 at the redshift of the quasar. We find no evidence of an overdensity of LAEs in the quasar field with respect to blank-field studies. Possible explanations for these findings may be that our survey volume is too small, or that the strong ionizing radiation from the quasar hinders galaxy formation in its immediate proximity. Another possibility is that these quasars are not situated in the dense environments predicted by some simulations

Constraining galaxy overdensities around three z ~ 6.5 quasars with ALMA and MUSE

Galaxie

Travelling waves for the Gross-Pitaevskii equation II

The purpose of this paper is to provide a rigorous mathematical proof of the existence of travelling wave solutions to the Gross-Pitaevskii equation in dimensions two and three. Our arguments, based on minimization under constraints, yield a full branch of solutions, and extend earlier results, where only a part of the branch was built. In dimension three, we also show that there are no travelling wave solutions of small energy.Comment: Final version accepted for publication in Communications in Mathematical Physics with a few minor corrections and added remark

APEX at the QSO MUSEUM: molecular gas reservoirs associated with z 3 quasars and their link to the extended Ly alpha emission

Interstellar matter and star formatio

Angular momenta creation in relativistic electron-positron plasma

Creation of angular momentum in a relativistic electron-positron plasma is explored. It is shown that a chain of angular momentum carrying vortices is a robust asymptotic state sustained by the generalized nonlinear Schrodinger equation characteristic to the system. The results may suggest a possible electromagnetic origin of angular momenta when it is applied to the MeV epoch of the early Universe.Comment: 20 pages, 6 figure

ALMA reveals a large overdensity and strong clustering of galaxies in quasar environments at z ~ 4

Galaxie

A comprehensive view of the interstellar medium in a quasar host galaxy at z ≈ 6.4

GalaxiesInterstellar matter and star formatio

A quasar discovered at redshift 6.6 from Pan-STARRS1

Luminous high-redshift quasars can be used to probe of the intergalactic medium in the early universe because their UV light is absorbed by the neutral hydrogen along the line of sight. They help us to measure the neutral hydrogen fraction of the high-z universe, shedding light on the end of reionization epoch. In this paper, we present a discovery of a new quasar (PSO J006.1240+39.2219) at redshift z = 6.61 ± 0.02 from Panoramic Survey Telescope & Rapid Response System 1. Including this quasar, there are nine quasars above z > 6.5 up to date. The estimated continuum brightness is M1450 = -25.96 ± 0.08. PSO J006.1240+39.2219 has a strong Ly α emission compared with typical low-redshift quasars, but the measured near-zone region size is RNZ = 3.2 ± 1.1 proper megaparsecs, which is consistent with other quasars at z ∼ 6