Related papers: The Baryon Content of Cosmic Structures
Galaxies are composed of baryonic stars and gas embedded in dark matter halos. Here I briefly review two aspects of the connection between baryons and their halos. (1) The observed baryon content of galaxies falls short of the cosmic baryon…
We quantify two main pathways through which baryonic physics biases cluster count cosmology. We create mock cluster samples that reproduce the baryon content inferred from X-ray observations. We link clusters to their counterparts in a dark…
Traditionally, galaxy clusters have been expected to retain all the material accreted since their formation epoch. For this reason, their matter content should be representative of the Universe as a whole, and thus their baryon fraction…
We present the baryon fractions of 2MASS groups and clusters as a function of cluster richness using total and gas masses measured from stacked ROSAT X-ray data and stellar masses estimated from the infrared galaxy catalogs. We detect X-ray…
The cluster baryon fraction is estimated from the CMB-scattering leptonic component of the intracluster medium (ICM); however, the observed cluster baryon fraction is less than the cosmic one. Understanding the origin of this discrepancy is…
I report the current status on the determinations of the baryon fractions and dynamical/lensing masses of galaxy clusters as well as the $\sigma$ - $T$ relationship, making use of all the published data in literature which include 304…
We analyse the X-ray surface brightness profiles of 19 moderately distant and luminous clusters of galaxies observed with the \EINOBS. Our aim is to determine cluster gas masses out to radii between 1 and $3\Mpc$, and to confirm the…
We show that a global relation between baryonic mass and virial velocity can be constructed from the scale of dwarf galaxies up to that of rich galaxy clusters. The slope of this relation is close to that expected if dark matter halos form…
[Abridged] The analysis of a sample of 52 clusters with precise and hypothesis-parsimonious measurements of mass shows that low mass clusters and groups are not simple scaled-down versions of their massive cousins in terms of stellar…
The large discrepancy between the amount of baryons that were synthesized in Big-Bang and that we detect at $z=0$ locked in stars inside galaxies and in hot/cold gas in galaxies. goup and clusters, is a well known crucial issue for present…
Stars and gas in galaxies, hot intracluster medium, and intergalactic photo-ionized gas make up at most half of the baryons that are expected to be present in the universe. The majority of baryons are still missing and are expected to be…
In the local Universe, the efficiency for converting baryonic gas into stars is very low. In dark matter halos where galaxies form and evolve, the average efficiency varies with galaxy stellar mass and has a maximum of about twenty percent…
We investigate if the discrepancy between estimates of the total baryon mass fraction obtained from observations of the cosmic microwave background (CMB) and of galaxy groups/clusters persists when a large sample of groups is considered. To…
One of the most direct way to constrain the matter density of the universe $\Omega_M$ is to measure the baryon content in X-Rays clusters of galaxies. Typical value of the mean gas mass fraction is $\fg \sim 0.15h^{-3/2}$ which leads to…
More than three quarters of the baryonic content of the Universe resides in a highly diffuse state that is difficult to observe, with only a small fraction directly observed in galaxies and galaxy clusters. Censuses of the nearby Universe…
The large scale structure of the present Universe is determined by the growth of dark matter density fluctuations and by the dynamical action of dark energy and dark matter. While much progress has been made in recent years in constraining…
The fraction of matter that is in the form of baryons or dark matter could have spatial fluctuations in the form of baryon-dark matter isocurvature fluctuations. We use big bang nucleosynthesis calculations compared with observed light…
Recent Cosmological measurements indicate that baryons comprise about four percent of the total mass-energy density of the Universe, which is in accord with the predictions arising from studies of the production of the lightest elements. It…
We exploit deep integral-field spectroscopic observations with KMOS/VLT of 240 star-forming disks at 0.6 < z < 2.6 to dynamically constrain their mass budget. Our sample consists of massive ($\gtrsim 10^{9.8} M_\odot$) galaxies with sizes…
We have analyzed the properties of a sample of 33 groups and clusters of galaxies and examine the baryon content to check for trends over a decade in temperature down to 1 keV. We examine the relative contribution of galaxies and ICM to…