Related papers: Baryonically Closed Galaxy Groups
We use multi-fiber spectroscopy of 12 nearby, poor groups of galaxies to address whether the groups are bound systems or chance projections of galaxies along the line-of-sight, why the members of each group have not already merged to form a…
The standard self-similar model of galaxy cluster formation predicts that the X-ray luminosity-temperature ($L_X$-$T_X$) relation of galaxy clusters should have been $L_X\propto T_X^2$ in absence of the baryonic physics, such as radiative…
We show that the high local baryonic fraction, M(bar) ~ 1/3 M(tot), found in groups and clusters of galaxies does not reconcile the observed cosmological baryon density with the standard Big-Bang prediction. Taking into account recent…
We present a combined optical and X-ray analysis of three optically selected X-ray bright groups with giant elliptical galaxies in the center. These massive ellipticals were targeted for XMM-Newton X-ray observations based on their large…
The Milky Way's million degree gaseous halo contains a considerable amount of mass that, depending on its structural properties, can be a significant mass component. In order to analyze the structure of the Galactic halo, we use XMM-Newton…
Self-gravitating systems such as elliptical galaxies appear to have a constant specific entropy and obey a scaling law relating their potential energy to their mass. These properties can be interpreted as due to the physical processes…
It is well established that brightest cluster galaxies (BCGs), residing in the center of galaxy clusters, are typically massive and quenched galaxies with cD or elliptical morphology. An optical survey suggested that an exotic galaxy…
We describe the evolution of hot interstellar gas in a family of low luminosity elliptical galaxies all having $M_B = -20$ but with different degrees of flattening (E0, E2, and E6) caused by rotation. The interstellar gas is furnished by…
We report the discovery of 12 new fossil groups of galaxies, systems dominated by a single giant elliptical galaxy and cluster-scale gravitational potential, but lacking the population of bright galaxies typically seen in galaxy clusters.…
The relationship between gas-rich galaxies and Ly-alpha absorbers is addressed in this paper in the context of the baryonic content of galaxy halos. Deep Arecibo HI observations are presented of two gas-rich spiral galaxies within 125 kpc…
Several popular cosmological models predict that most of the baryonic mass in the local universe is located in filamentary and sheet-like structures associated with galaxy overdensities. This gas is expected to be gravitationally heated to…
We make an inventory of the baryonic and gravitating mass in structures ranging from the smallest galaxies to rich clusters of galaxies. We find that the fraction of baryons converted to stars reaches a maximum between M500 = 1E12 and 1E13…
X-ray emission from hot (T = 10^7 K) interstellar gas in massive elliptical galaxies indicates that 10^{10} M_sun has cooled over a Hubble time, but optical and radio evidence for this cold gas is lacking. We provide detailed theoretical…
The number density and clustering properties of Lyman-break galaxies (LBGs) observed at redshift $z\sim 3$ are best explained by assuming that they are associated with the most massive haloes at $z\sim 3$ predicted in hierarchical models of…
We present the analysis of baryonic and non-baryonic matter distributions in a sample of eleven nearby clusters (0.03<z<0.09) with temperatures between 4.4 and 9.4 keV. These galaxy clusters have been studied in detail using X-ray data and…
We review X-ray constraints on dark matter in giant elliptical galaxies (10^{12} M_sun <~ M_vir <~ 10^{13} M_sun) obtained using the current generation of X-ray satellites, beginning with an overview of the physics of the hot interstellar…
We compare the empirical relationships between the mass of a galaxy's globular system M_GCS, the gas mass in the hot X-ray atmosphere M_X within a fiducial radius of 5 r_e, the total gravitational mass M_grav within 5 r_e, and lastly the…
Observations of local X-ray absorbers, high-velocity clouds, and distant quasar absorption line systems suggest that a significant fraction of baryons may reside in multi-phase, low-density, extended, ~100 kpc, gaseous halos around normal…
The enormous range of X-ray luminosities among elliptical galaxies with similar optical luminosities can be attributed to large scatter and systematic variations in the dark halo mass determined from X-ray observations. The mean halo mass…
The Circumgalactic Medium (CGM) of late-type galaxies is characterized using UV spectroscopy of 11 targeted QSO/galaxy pairs at z < 0.02 with the Hubble Space Telescope Cosmic Origins Spectrograph and ~60 serendipitous absorber/galaxy pairs…