Conveners
First stars and their remnants as dark matter probes: Monday block 1
- cosmin ilie
First stars and their remnants as dark matter probes: Monday block 2
- cosmin ilie
Description
JWST observations of the earliest luminous structures in the Universe are beginning to challenge the standard models of the formation and evolution of the first stars and galaxies. Namely, they imply that a large fraction of the first galaxies ever assembled converted gas to stars at an incredible, almost 100% efficiency. Moreover, the most distant quasars observed are powered by black holes that are unlikely to have been seeded by Population III stars, and, instead, imply the existence of very massive Black Hole seeds at high redshifts. A possible solution to both of those puzzles are stars formed out of zero metallicity gas clouds at the center of high redshift Dark Matter halos and powered by Dark Matter, i.e. Dark Stars. The main over-arching question addressed by talks in this parallel session is: what can we learn about the nature of Dark Matter from observations of the first stars, their BH remnants, and the first galaxies in the Universe.
"Dark stars" are a theoretical class of celestial objects powered by dark matter annihilation rather than nuclear fusion. I will review the conditions in the early universe conducive to the formation of dark stars, covering the theoretical basis of dark matter annihilation as an energy source. I will discuss the expected properties of dark stars, including their size, luminosity, lifespan, and...
The James Webb Space Telescope (JWST) is unveiling astounding results on the composition and evolution of the cosmo at very high redshifts. In this talk, I develop a UV luminosity function model for high-redshift galaxies, considering parameters such as the stellar formation rate, dust extinction, and halo mass function, calibrated at $z = 4\textrm{-}7$. Testing the model against higher...
Early James Webb Space Telescope (JWST) observations defied expectations from the standard 𝚲CDM model of cosmology. There is an overabundance of very massive, high-redshift galaxies and quasars when the universe was only a few hundred million years old. Supermassive Dark Stars (SMDS) offer a potential solution to this paradox. They are candidates for the first stars in the universe, alongside...
JWST’s discoveries of black holes with masses ∼ 108M⊙ when the Universe was less than 5% of its current age challenge our understanding of star and black hole formation. The leading hypothesis to explain these observations is the inflowing of a large amount of gas directly onto the SMBH from galaxy-wide scales while maintaining gas stability against star formation. However, alternatives in...
The origin of supermassive black holes (SMBHs) is a key open question for contemporary astrophysics and cosmology. Here we discuss the predictions of a model of SMBH formation from Pop III.1 protostars, i.e., metal-free stars forming in locally isolated dark matter minihalos, where dark matter annihilation has a chance to alter the structure of the star allowing growth to supermassive scales...
Supermassive dark stars (SMDS) are luminous stellar objects formed in the early Universe at redshift $z \sim 10-20$, made primarily of hydrogen and helium, yet powered by dark matter.
We examine the capabilities of the Roman Space Telescope (RST), and find it able to identify $ \sim 10^6M_{\odot}$ SMDSs at redshifts up to $z\sim 14$. With a gravitational lensing factor of $\mu\sim 100$, RST...
