相关论文: The Cosmic Timeline Implied by the JWST Reionizati…
Limiting the number of model-dependent assumptions to a minimum, we discuss the detectability of the sources responsible for reionization with existing and planned telescopes. We conclude that if reionization sources are UV-efficient,…
Recently, the James Webb Space Telescope (JWST) has found early galaxies producing photons from more efficient ionization than previously assumed. This may suggest a reionization process with a larger reionization optical depth, $\tau_{\rm…
The overabundance of the red and massive candidate galaxies observed by the James Webb Space Telescope (JWST) implies efficient structure formation or large star formation efficiency at high redshift $z\sim 10$. In the scenario of a low or…
Early observations with JWST indicate an over-abundance of bright galaxies at redshifts $z \gtrsim 10$ relative to Hubble-calibrated model predictions. More puzzling still is the apparent lack of evolution in the abundance of such objects…
JWST is revealing a new remarkable population of high-redshift ($z\gtrsim4$), low-luminosity Active Galactic Nuclei (AGNs) in deep surveys and detecting the host galaxy stellar light in the most luminous and massive quasars at $z\sim 6$ for…
Early JWST observations reveal an unexpectedly abundant population of high-redshift candidate massive galaxies at $z \gtrsim 7$, and recent DESI measurements show a preference for dynamical dark energy, which together present a significant…
Early JWST spectroscopic campaigns have confirmed the presence of strong [O III] line-emitting galaxies in the redshift interval $7<z<9$. Although deduced earlier from Spitzer photometry as indicative of young stellar populations, some…
Recent cosmological observations show hints for possible deviations from the standard $\Lambda$CDM paradigm at late times. To study such deviation, we introduce a minimal phenomenological framework in which the total equation of state of…
We show that by jointly fitting cosmic microwave background (CMB) and astrophysical data - a compilation of UV luminosity data from the Hubble Frontier Field and neutral hydrogen data from distant sources-, we can infer on the shape of the…
Using CANUCS imaging we found an apparent major merger of two $z\sim5$ ultra-low-mass galaxies ($M_\star\sim10^{7}M_\odot$ each) that are doubly imaged and magnified $\sim$12-15$\times$ by the lensing cluster MACS 0417. Both galaxies are…
We show that the star formation history, the reionization history and the present luminosity function of galaxies are reproduced in a simple gravitational collapse model within the $\Lambda$CDM regime to almost a quantitative accuracy, when…
The James Webb Space Telescope (JWST) is discovering an increasing number of galaxies well into the early stages of the Epoch of Reionization (EoR). Many of these galaxies are clustered with strong Lyman alpha (Ly$\alpha$) emission,…
21cm emission from residual neutral hydrogen after the epoch of reionization can be used to trace the cosmological power spectrum of density fluctuations. Using a Fisher matrix formulation, we provide a detailed forecast of the constraints…
Star-forming galaxies can exhibit strong morphological differences between the rest-frame far-UV and optical, reflecting inhomogeneities in star-formation and dust attenuation. We exploit deep, high resolution NIRCAM 7-band observations to…
Recent observations from the James Webb Space Telescope (JWST) have uncovered an unexpectedly large abundance of massive, UV-bright galaxies at high redshifts, presenting a significant challenge to established galaxy formation models within…
The high-redshift progenitors of present-day galaxy clusters are believed to substantially contribute to the global star-formation rate density and drive the large-scale reionization of the Universe. Here we present a blind and unbiased…
JWST is providing constraints on the history of reionization owing to its ability to detect faint galaxies at $z\gg6$. Modeling this history requires understanding both the ionizing photon production rate ($\xi_{\rm ion}$) and the fraction…
Recently, models of the quasar luminosity function (QLF) rooted on large observational compilations have been produced that, unlike their predecessors, feature a smooth evolution with time. This bypasses the need to assume an ionizing…
Observations with the {\it James Webb Space Telescope} have revealed a high abundance of bright galaxies at redshift, $z\gtrsim 12$, which has been widely interpreted as conflicting with the $\Lambda$CDM model. In Cowley et al. (2018)…
The Cosmic Defect theory has been confronted with four observational constraints: primordial nuclear species abundances emerging from the big bang nucleosynthesis; large scale structure formation in the universe; cosmic microwave background…