相关论文: The prospects of finding the first quasars in the …
The generation and evolution of dust in galaxies are important tracers for star formation, and can characterize the rest-frame ultraviolet to infrared emission from the galaxies. In particular understanding dust in high-redshift galaxies…
The James Webb Space Telescope (JWST) has recently uncovered a new record-breaking quasar, UHZ1, at a redshift of $z\sim10$. This discovery continues JWST's trend of confronting the expectations from the standard $\Lambda$CDM model of…
Distant quasars are unique tracers to study the formation of the earliest supermassive black holes (SMBHs) and the history of cosmic reionization. Despite extensive efforts, only two quasars have been found at $z\ge7.5$, due to a…
The detection of resonance absorption lines against known objects such as individual galaxies and clusters of galaxies is a powerful approach for studying the gas content of these systems. We describe an efficient method of identifying…
Quasars accreting at very high rates are believed to be prime movers of galactic evolution because of their high radiative and mechanical output. The study presented in this paper investigates a sample of six highly accreting quasars at…
The detection of gravitationally redshifted optical emission lines has been reported just for a few active galaxies. In this paper we give a short overview of studies that analyzed or exploited the detection of the gravitational redshift in…
Thanks to deep optical to near-IR imaging and spectroscopy, significant progress is made in characterizing the rest-frame UV to optical properties of galaxies in the early universe (z > 4). Surveys with Hubble, Spitzer, and ground-based…
Direct-collapse black holes (DCBHs) may be the seeds of the first quasars, over 200 of which have now been detected at $z > 6$ . The James Webb Space Telescope (JWST) could detect DCBHs in the near infrared (NIR) at $z \lesssim 20$ and…
Quasars are galaxies hosting accreting supermassive black holes; due to their brightness, they are unique probes of the early universe. To date, only few quasars have been reported at $z > 6.5$ ($<$800 Myr after the Big Bang). In this work,…
Studies of the formation and early history of galaxies have been hampered by the difficulties inherent in detecting faint galaxy populations at high redshift. As a consequence, observations at the highest redshifts (3.5 < z < 5) have been…
We report the results of a pilot study of CO$(4-3)$ emission line of three {\it WISE}-selected hyper-luminous, dust-obscured quasars (QSOs) with sensitive ALMA Band 3 observations. These obscured QSOs with $L_{\rm bol}>10^{14}L_\odot$ are…
In less than two years of operation, the James Webb Space Telescope (JWST) has already accelerated significantly our quest to identify active massive black holes (BHs) in the first billion years of the Universe's history. At the time of…
Recent discoveries by the Sloan Digital Sky Survey (SDSS) of four bright redshift z=6 quasars could constrain the mechanism by which the supermassive black holes powering these sources are assembled. Here we compute the probability that the…
We present spectroscopic measurements for 71 galaxies associated with 62 of the brightest high-redshift submillimeter sources from the Southern fields of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS), while targeting 85…
Quasars are among the most luminous objects in the universe, and they can be studied in detail up to the highest known redshift. Assuming that the gas associated with quasars is closely related to the interstellar medium of the host galaxy,…
The James Webb Space Telescope (JWST) will enable observations of galaxies at redshifts z > 10 and hence allow to test our current understanding of structure formation at very early times. Previous work has shown that the very first…
The James Webb Space Telescope (JWST), scheduled for launch in 2014, is expected to revolutionize our understanding of the high-redshift Universe. Even so, many of the most interesting sources that may be hiding at redshifts z~10…
We search for high-redshift (z>4.5) X-ray AGNs in the deep central (off-axis angle <5.7') region of the 7 Ms Chandra Deep Field-South X-ray image. We compile an initial candidate sample from direct X-ray detections. We then probe more…
We use 62,185 quasars from the Sloan Digital Sky Survey DR5 sample and standard virial mass scaling laws based on the widths of H beta, Mg II, and C IV lines and adjacent continuum luminosities to explore the maximum mass of quasars as a…
Exceptionally bright quasars with redshifts up to z=6.28 have recently been discovered. Quasars are thought to be powered by the accretion of gas onto supermassive black holes at the centres of galaxies. Their maximum (Eddington) luminosity…