相关论文: The JWST and standard cosmology
Combining the public JWST/NIRCam imaging programs CEERS, PRIMER and JADES, spanning a total area of $\sim500\,{\rm arcmin}^2$, we obtain a sample of $>$30,000 galaxies at $z_{\rm phot}\sim4-9$ that allows us to perform a complete,…
Numerical simulations have established that star clusters with densities comparable to the high redshift ($z>6$-$10$) James Webb Space Telescope (JWST) proto globular clusters may build up extremely massive (EMSs; $m_\mathrm{\star}>1000…
Massive black holes are nowadays believed to reside in most local galaxies. Studies have also established a number of relations between the MBH mass and properties of the host galaxy such as bulge mass and velocity dispersion. These results…
Approximately two hundred supermassive black holes (SMBHs) have been discovered within the first $\sim$Gyr after the Big Bang. One pathway for the formation of SMBHs is through the collapse of supermassive stars (SMSs). A possible obstacle…
Recent observations of quasars powered by supermassive black holes (SMBHs) out to z > 7 constrain both the initial seed masses and the growth of the most massive black holes (BHs) in the early universe. Here we elucidate the implications of…
The most massive black holes, lurking at the centers of large galaxies, must have formed less than a billion years after the big bang, as they are visible today in the form of bright quasars at redshift larger than six. Their early…
We report two secure ($z=3.775, 4.012$) and one tentative ($z\approx3.767$) spectroscopic confirmations of massive and quiescent galaxies through $K$-band observations with Keck/MOSFIRE and VLT/X-Shooter. The stellar continuum emission, the…
We compute the number density of nonlinear seed fluctuations which have the right number density to be able to explain the presence of one supermassive black hole per galaxy, as a function of redshift. We find that there is an interesting…
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 observations confirm the existence of galaxies as early as 300Myr and at a higher number density than expected based on galaxy formation models and HST observations. Yet, sources confirmed spectroscopically in the first 500Myr have…
JWST has revealed a population of super-luminous early galaxies with a volume density in excess of most expectations. The spectra reveal diverse properties: while some reveal strong emission lines characteristic of galaxies in the midst of…
We investigate the possibility that present-day galactic haloes contain a population of massive black holes (MBHs) that form by hierarchical merging of the black hole remnants of the first stars. Some of the MBHs may be large enough or…
We discuss some of the key open questions regarding the formation and evolution of globular clusters (GCs) during galaxy formation and assembly within a cosmological framework. The current state-of-the-art for both observations and…
JWST is revolutionizing our understanding of the high-$z$ Universe by expanding the black hole horizon, looking farther and to smaller masses, and revealing the stellar light of their hosts. By examining JWST galaxies at $z=4-7$ that host…
The star-forming main sequence of galaxies has now been observed out to redshifts of $z\sim6$ and beyond. However, it remains unclear how long typical galaxies remain on or near it as they evolve, and how frequently they return after…
Stellar halos around galaxies retain fundamental evidence of the processes which lead to their build up. Sophisticated models of galaxy formation in a cosmological context yield quantitative predictions about various observable…
JWST observations of high redshift galaxies are used to measure their star formation histories - the buildup of stellar mass in the earliest galaxies. Here we use a novel analysis program, SEDz*, to compare near-IR spectral energy…
The recent observations by the James Webb Space Telescope (JWST) have revealed a larger number of bright galaxies at $z\gtrsim10$ than was expected. The origin of this excess is still under debate, although several possibilities have been…
JWST has detected many overmassive galactic systems at $z > 4$, where the mass of the black hole, $M_\bullet$, is $10-100$ times larger than expected from local relations, given the host's stellar mass, $M_\star$. This Letter presents a…
The James Webb Space Telescope has found an unexpected population of high-mass galaxies ($\log (M^\star / {\rm M} _\odot) \gtrsim 10$) with extremely small effective radii ($\sim 100\,\rm pc$) at $z \gtrsim 6$. Also, the existence of an…