Related papers: The challenge of measuring and mapping the missing…
The discovery of Fast Radio Bursts (FRBs) at cosmological distances has opened a powerful window on otherwise unseen matter in the Universe. In the 2020s, observations of $>10^{4}$ FRBs will assess the baryon contents and physical…
Most of the baryons in the present-day universe are thought to reside in intergalactic space at temperatures of 10^5-10^7 K. X-ray emission from these baryons contributes a modest (~10%) fraction of the ~ 1 keV background whose prominence…
The general arguments for baryonic and galactic dark matter are presented. Limits coming from a variety of theoretical considerations and observations are discussed. The surviving candidates for galactic baryonic dark matter seem most…
After briefly reviewing the good agreement between large-scale observations and the predictions of the now-standard CDM theory and problems with the MOND alternative, I summarize several of the main areas of possible disagreement between…
The ratios between different baryonic species masses are studied. The result is used to tentatively predict some missing baryonic masses, still not experimentally observed.
The search for faint emission or absorption lines in astronomical spectra has received considerable attention in recent years, especially in the X-ray wavelength range. These features usually appear as a deficit or excess of counts in a…
Approximately 30 to 50 percent of the total baryons in the present universe is supposed to take a form of warm/hot intergalactic medium (WHIM) whose X-ray continuum emission is very weak. In order to carry out a direct and homogeneous…
The number of detected baryons in the low-redshift Universe (z < 1) is far small er than the corresponding number of baryons observed at higher redshift. According to hydrodynamical simulations for the formation of structure in the…
Metals are found in all baryonic phases and environments, and our knowledge of their distribution `in and around galaxies' has significantly improved over the past few years. Theoretical work has shown that the fraction of metals in…
Mapping the expansion of the universe gives clues to the underlying physics causing the recently discovered acceleration of the expansion, and enables discrimination among cosmological models. We examine the utility of measuring the rate of…
I briefly describe some results about luminous distant dusty galaxies obtained in the 5 years since sensitive two-dimensional bolometer array cameras became available. The key requirements for making additional progress in understanding the…
The hot, diffuse gas that fills the largest overdense structures in the Universe -- clusters of galaxies and a web of giant filaments connecting them -- provides us with tools to address a wide array of fundamental astrophysical and…
Variability in gravitationally lensed quasars can be due to intrinsic fluctuations of the quasar or due to ``microlensing'' by compact objects along the line of sight. If disentangled from each other, microlens-induced variability can be…
The growth factor of linear fluctuations is probably one of the least known quantity in observational cosmology. Here we discuss the constraints that baryon oscillations in galaxy power spectra from future surveys can put on a conveniently…
Weak lensing surveys that can potentially place strong constraints on dark energy parameters can only do so if the source redshift means and error distributions are very well known. We investigate prospects for controlling errors in these…
Cosmological nucleosynthesis calculations imply that many of the baryons in the Universe must be dark. We discuss the likelihood that some of these dark baryons may reside in galaxies as Massive Compact Halo Objects (MACHOs), the remnants…
Recent multifrequency observations contribute to derive a comprehensive picture of the origin and evolution of relativistic particles in galaxy clusters. In this review I briefly discuss theoretical aspects and open problems of this…
The ubiquitous presence of dark matter in the universe is today a central tenet in modern cosmology and astrophysics. Ranging from the smallest galaxies to the observable universe, the evidence for dark matter is compelling in dwarfs,…
Thanks to high-resolution and non-dispersive spectrometers onboard future X-ray missions such as XRISM and Athena, we are finally poised to answer important questions about the formation and evolution of galaxies and large-scale structure.…
The cosmic baryon density fraction ($\Omega_{\rm b}$) is intrinsically correlated with the Hubble constant ($H_0$) through the critical density of the Universe. In the context of the decade-long $H_0$ tension, the significant discrepancy…