The enrichment of the intergalactic medium with heavy elements is a process that lies at the nexus of poorly-understood aspects of physical cosmology. We review current understanding of the processes that may remove metals from galaxies, the basic predictions of these models, the key observational constraints on enrichment, and how intergalactic enrichment may be used to test cosmological simul...

The determination of the densities of intergalactic photons from the FIR to the UV produced by stellar emission and dust reradiation at various redshifts can provide an independent measure of the star formation history of the universe. Using recent Spitzer and GALEX data in conjunction with other observational inputs, Stecker, Malkan and Scully have calculated the intergalactic photon density a...

Star formation in interacting systems may take place in various locations, from the dust–enshrouded core of Ultraluminous Infrared Galaxies to more unusual places such as the debris of colliding galaxies expelled into the intergalactic medium. Determining whether star-formation proceeds in the latter environment, far from the parent galaxies, in a similar way as in spiral disks has motivated th...

Abstract We analyze the dynamics and observational signatures of axion clouds formed via superradiant instability around primordial black holes, focusing on mass range 10 14 - 18 kg where latter may account for all dark matter. take into leading effects self-interactions, showing that, even though these limit number axions produced within each cloud, a large become free hole's gravitational pot...

We study the upper projected bounds on dark matter fraction in form of primordial black holes (PBHs) with a non-zero spin by using absorption feature global 21-cm signal at redshift z ~ 17. The mass and are fundamental properties hole, they can substantially affect evaporation rate hole. evaporating hole inject energy into intergalactic medium heat gas. Subsequently, it modify amplitude signal....

We use published measurements of the transmission power spectrum of the Lyman α forest to constrain several parameters that describe cosmology and thermal properties of the intergalactic medium (IGM). A 6 parameter grid is constructed using Particle-Mesh dark matter simulations together with scaling relations to make predictions for the gas properties. We fit for all parameters simultaneously a...

In this paper we investigate how the Reionization process is affected by early galaxy formation in different cosmological scenarios. We use a semi-analytic model with suppressed initial power spectra to obtain UV Luminosity Function thermal Warm Dark Matter and sterile neutrino cosmologies. retrace ionization history of intergalactic medium hot stellar emission only, exploiting fixed variable p...