相关论文: An ultra-luminous quasar with a twelve-billion-sol…

Luminous quasars at $z > 6$ are key probes of early supermassive black hole (SMBH) growth, massive galaxy evolution, and intergalactic medium properties during cosmic reionization. However, their discovery is very challenging due to their…

To date, most of the luminous quasars known at $z\sim6$ have been found to be in maximal accretion with the Eddington ratios, $\lambda_{\rm{Edd}}\sim1$, suggesting enhanced nuclear activities in the early universe. However, this may not be…

In this letter we report the serendipitous discovery of a genuine type-II quasar at z = 1.65 using integral-field data from VIMOS on the VLT. This is the first discovery of a type-II quasar at z > 1 from optical data alone. J094531-242831,…

We present our first results of the survey for high redshift quasars at $5 \lesssim {\rm z} \lesssim 5.7$. The search for quasars in this redshift range has been known to be challenging due to limitations of filter sets used in previous…

It remains debatable how billion-solar-mass supermassive black holes (SMBHs) form and evolve within the first billion years. We report results from a James Webb Space Telescope (JWST)/NIRSpec integral field unit (IFU) survey of 27 luminous…

We present the discovery of three new quasars at z>6 in 1300 deg^2 of SDSS imaging data, J114816.64+525150.3 (z=6.43), J104845.05+463718.3 (z=6.23) and J163033.90+401209.6 (z=6.05). The first two objects have weak Ly alpha emission lines;…

We report on the discovery of a Type 1 quasar, SDSS 0956+5128, with a surprising combination of extreme velocity offsets. SDSS 0956+5128 is a broad-lined quasar exhibiting emission lines at three substantially different redshifts: a…

Radio sources at the highest redshifts can provide unique information on the first massive galaxies and black holes, the densest primordial environments, and the epoch of reionization. The number of astronomical objects identified at z>6…

We aim at probing the emission mechanism of the accreting super massive black holes in the high redshift Universe. We study the X-ray spectrum of ULAS1120+0641, the highest redshift quasar detected so far at z=7.085, which has been deeply…

Recently, Carnall et al. discovered two bright high redshift quasars using the combination of the VST ATLAS and WISE surveys. The technique involved using the 3-D colour plane i-z:z-W1:W1-W2 with the WISE W1 (3.4 micron) and W2 (4.5 micron)…

We combine near-infrared imaging in two bands from the Hubble Space Telescope (HST) with archival observations of molecular gas to study SDSS J160705.16+533558.6 (J1607), an extremely luminous broad-line quasar at $z = 3.65$ that is also…

We report the discovery of SDSSJ115517.35+634622.0, a previously unknown gravitationally lensed quasar. The lens system exhibits two images of a $z = 2.89$ quasar, with an image separation of $1{\farcs}832 \pm 0.007$ . Near-IR imaging of…

We investigate the relative occurrence of radio--loud and radio-quiet quasars in the first billion years of the Universe, powered by black holes heavier than one billion solar masses. We consider the sample of high-redshfit blazars detected…

We report the discovery of a quasar close to SDSS J0927+2943 (z = 0.713), which is a massive binary / recoiling black hole candidate. The companion quasar is at a projected distance of 125 h_70^{-1} kpc and exhibits a radial velocity…

We present optical and near-infrared imaging of the field of the z=7.0842 quasar ULAS J112001.48+064124.3 taken with the Hubble Space Telescope. We use these data to search for galaxies that may be physically associated with the quasar,…

The recent Chandra-JWST discovery of a quasar in the z = 10.1 galaxy UHZ1 reveals that accreting supermassive black holes (SMBHs) were already in place 470 million years after the Big Bang. The Chandra X-ray source detected in UHZ1 is a…

(abriged)In this paper we study different properties of quasars and their host galaxies at high redshifts up to z~3.4. We compare our results to those of other authors and discuss the correlation between galaxy evolution and quasar…

We present the results of new infrared spectroscopic observations of 37 quasars at z~3, selected based on the optical r'-band magnitude and the availability of nearby bright stars for future imaging follow-up with Adaptive Optics system.…

The recent discovery of a large number of massive black holes within the first two billion years after the Big Bang, as well as their peculiar properties, have been largely unexpected based on the extrapolation of the properties of luminous…

The tight relationship between the masses of black holes and galaxy spheroids in nearby galaxies implies a causal connection between the growth of these two components. Optically luminous quasars host the most prodigious accreting black…