Related papers: The prospects of finding the first quasars in the …
(abridged) We explore how ALMA observations can probe high-redshift galaxies in unprecedented detail. We discuss the main observables that are excited by the large-scale starburst, and formulate expectations for the chemistry and the fluxes…
The James Webb Space Telescope (JWST) is challenging our understanding of the nature of the very first galaxies in the Universe, having discovered a surprising abundance of very massive galaxies in early cosmic epochs. By applying a model…
We have obtained deep, multi-band imaging observations around three of the most distant known quasars at redshifts z>6. Standard accretion theory predicts that the supermassive black holes present in these quasars were formed at a very…
This work aims at studying the $M_{BH}-M_{dyn}$ relation of a sample of $2<z<7$ quasars by constraining their host galaxy masses through full kinematical modeling of the cold gas kinematics, thus avoiding all possible biases and effects…
Future observations with ALMA will be able to detect star-forming primordial gal axies, and perhaps even their dwarf spheroidal satellites, in CO emission lines at redshifts approaching 10. These observations will compliment other tools…
ALMA will become fully operational in a few years and open a new window on primordial galaxies. The mm and submm domain is privileged, since the peak of dust emission between 60 and 100 microns is redshifted there for z= 5-10, and the…
The James Webb Space Telescope (JWST) has discovered a surprising abundance of bright galaxy candidates in the very early Universe ($< 500$ Myrs after the Big Bang), calling into question current galaxy formation models. Spectroscopy is…
Many present-day galaxies are known to harbor supermassive, >10^6 Mo, black holes. These central black holes must have grown through accretion from less massive seeds in the early universe. The molecules CO and H2 can be used to trace this…
We present measurements of black hole masses and Eddington ratios for a sample of 38 bright (M$_{1450}$ < -24.4 mag) quasars at 5.8 < z < 7.5, derived from VLT/X-shooter near-IR spectroscopy of their broad CIV and MgII emission lines. The…
ALMA is now fully operational, and has been observing in early science mode since 2011. The millimetric (mm) and sub-mm domain is ideal to tackle galaxies at high redshift, since the emission peak of the dust at 100$\mu$m is shifted in the…
We present ALMA observations of cold dust and molecular gas in four high-luminosity, heavily reddened (A$_{\rm{V}} \sim 2.5-6$ mag) Type 1 quasars at $z\sim2.5$ with virial M$_{\rm{BH}} \sim 10^{10}$M$_\odot$, to test whether dusty, massive…
By implementing a model of primordial dust emission, we predict dust-continuum fluxes for massive galaxy sources similar to those recently detected by JWST at $z \gtrsim 7$. Current upper flux limits, obtained with ALMA for some of these…
We discuss observations of the first galaxies, within cosmic reionization, at centimeter and millimeter wavelengths. We present a summary of current observations of the host galaxies of the most distant QSOs ($z \sim 6$). These observations…
We study the observational signatures of a potential population of low-luminosity quasars at high redshifts in a LambdaCDM cosmology. We derive the evolution of the quasar luminosity function at fainter luminosities and higher redshifts…
Groups and clusters of galaxies hosting a quasar can be found through the detection of Lyman-alpha absorption lines beyond the quasar redshift. The effect occurs whenever the distortion to the redshift distribution of Lyman-alpha clouds…
In a multi-wavelength survey of $13$ quasars at $5.8\lesssim z\lesssim6.5$, that were pre-selected to be potentially young, we find five objects with extremely small proximity zone sizes that may imply UV-luminous quasar lifetimes of…
High-redshift quasars ($z\gtrsim6$), powered by black holes (BHs) with large inferred masses, imply rapid BH growth in the early Universe. The most extreme examples have inferred masses of $\sim \! 10^9\,$M$_\odot$ at $z = 7.5$ and $\sim \!…
The first stars in the history of the Universe are likely to form in the dense central regions of 10^5-10^6 Msolar cold dark matter halos at z=10-50. The annihilation of dark matter particles in these environments may lead to the formation…
Empirical studies of the first generation of stars and quasars will likely become feasible within the next decade in several different wavelength bands. Microwave anisotropy experiments, such as MAP or Planck, will set constraints on the…
Quasars at high redshift provide direct information on the mass growth of supermassive black holes and, in turn, yield important clues about how the Universe evolved since the first (Pop III) stars started forming. Yet even basic questions…