The Density Profiles of Massive, Relaxed Galaxy Clusters - HAL-Insu
... with a unimodal velocity distribution in which the BCG is at rest in the cluster potential, as shown in Figure 2. A2390 shows slightly more complicated X-ray emission that is characterized primarily by a low-level extension to the northwest on ∼ 200 kpc scales, in the same location as an enhancement ...
... with a unimodal velocity distribution in which the BCG is at rest in the cluster potential, as shown in Figure 2. A2390 shows slightly more complicated X-ray emission that is characterized primarily by a low-level extension to the northwest on ∼ 200 kpc scales, in the same location as an enhancement ...
IXO as an observatory in the large telescopes era
... The current deepest surveys with Chandra reach great depths at the central aim point. These have yielded a handful of AGN candidates at z>5 (Luo et al 2010), but none is yet confirmed at z>6. To harvest significant samples of moderate luminosity AGN at z=7-10, however, we need to reach this kind of ...
... The current deepest surveys with Chandra reach great depths at the central aim point. These have yielded a handful of AGN candidates at z>5 (Luo et al 2010), but none is yet confirmed at z>6. To harvest significant samples of moderate luminosity AGN at z=7-10, however, we need to reach this kind of ...
Direct Dark Matter Search with the XENON100 Experiment
... In the observable universe, ordinary matters—matter that we are made of: proton, neutron and electron; and other matter/anti-matter we have observed and are explained in the Standard Model of Particle Physics, account for only 4.6 % of the total mass-energy components. About 23 % of the universe is ...
... In the observable universe, ordinary matters—matter that we are made of: proton, neutron and electron; and other matter/anti-matter we have observed and are explained in the Standard Model of Particle Physics, account for only 4.6 % of the total mass-energy components. About 23 % of the universe is ...
Axion Cosmology
... Andreas Ringwald | Implications of the early LHC for cosmology | 18-20 April 2012 | Page 10 ...
... Andreas Ringwald | Implications of the early LHC for cosmology | 18-20 April 2012 | Page 10 ...
Farthest Neighbor: The Distant Milky Way Satellite Eridanus II
... there is a star cluster whose projected position is very close to the center of EriII, making it the least luminous galaxy known to host a (possibly central) star cluster. The features described above make EriII one of the most interesting of the newly discovered Milky Way satellites for spectrosc ...
... there is a star cluster whose projected position is very close to the center of EriII, making it the least luminous galaxy known to host a (possibly central) star cluster. The features described above make EriII one of the most interesting of the newly discovered Milky Way satellites for spectrosc ...
The dark matter crisis: falsification of the current standard model of
... want: we shall look for, and find, confirmations, and we shall look away from, and not see, whatever might be dangerous to our pet theories. In this way it is only too easy to obtain what appears to be overwhelming evidence in favor of a theory which, if approached critically, would have been refute ...
... want: we shall look for, and find, confirmations, and we shall look away from, and not see, whatever might be dangerous to our pet theories. In this way it is only too easy to obtain what appears to be overwhelming evidence in favor of a theory which, if approached critically, would have been refute ...
Environment and self-regulation in galaxy formation
... very efficient and fast, and can easily be applied to large data sets like SDSS. A further advantage is that it considers a large wavelength range of the spectrum and hence gives a better estimate of the real average population. Finally, the consideration of a larger set of absorption features incre ...
... very efficient and fast, and can easily be applied to large data sets like SDSS. A further advantage is that it considers a large wavelength range of the spectrum and hence gives a better estimate of the real average population. Finally, the consideration of a larger set of absorption features incre ...
Super-solar Metal Abundances in Two Galaxies at ζ ∼ 3.57
... can only infer an upper limit for Al ii, the expected value can be estimated from other ions with similar ionization potential, from which we conclude that NAl II /NAl III > 10. Some heavy elements (e.g., iron or nickel) can be partly locked up in dust grains, and measured column densities (which ar ...
... can only infer an upper limit for Al ii, the expected value can be estimated from other ions with similar ionization potential, from which we conclude that NAl II /NAl III > 10. Some heavy elements (e.g., iron or nickel) can be partly locked up in dust grains, and measured column densities (which ar ...
Cold versus Warm Dark Matter Simulations of a Galaxy Group
... We begin with a cosmographic description of the two simulated groups. Our simulations produce three dominant objects which we name galaxy A, B, and C in decreasing mass. In the CDM case, these closely resemble the MW, Andromeda (M31), and Triangulum (M33). An image of the two groups can be seen in F ...
... We begin with a cosmographic description of the two simulated groups. Our simulations produce three dominant objects which we name galaxy A, B, and C in decreasing mass. In the CDM case, these closely resemble the MW, Andromeda (M31), and Triangulum (M33). An image of the two groups can be seen in F ...
Elliptical Galaxies
... Dark haloes: mass at large radius Spiral galaxy rotation curves have been used to show that they are embedded in dark haloes that contain three to ten times as much mass as is visible in stars, gas and dust. Can dark haloes be detected in elliptical galaxies? The velocity dispersion in many galaxies ...
... Dark haloes: mass at large radius Spiral galaxy rotation curves have been used to show that they are embedded in dark haloes that contain three to ten times as much mass as is visible in stars, gas and dust. Can dark haloes be detected in elliptical galaxies? The velocity dispersion in many galaxies ...
Where stars are born: Javier Blasco-Herrera
... The morphology and kinematics of galaxies can solve some of those questions. Many starbursts, for example, show double nuclei, tidal tails and/or companions, which together with very perturbed rotation points towards mergers and interactions being the cause of the trigger. After the starburst fades, ...
... The morphology and kinematics of galaxies can solve some of those questions. Many starbursts, for example, show double nuclei, tidal tails and/or companions, which together with very perturbed rotation points towards mergers and interactions being the cause of the trigger. After the starburst fades, ...
nainan k. varghese
... Time is a functional entity of duration compared with the interval required for a matter body, which is assumed to move at constant (linear) speed, to move through a definite distance in space. Work is the magnitude of (additional) distortions in universal medium. Work, being displacements of quanta ...
... Time is a functional entity of duration compared with the interval required for a matter body, which is assumed to move at constant (linear) speed, to move through a definite distance in space. Work is the magnitude of (additional) distortions in universal medium. Work, being displacements of quanta ...
The Collision Between The Milky Way And Andromeda
... 16% (Spergel et al. 2003). Since the Milky Way and Andromeda galaxy models only include baryons in the galactic disk and bulge components, they are far short of this value. We therefore set the Local Group medium to be 20% primordial gas, by mass, so that the entire region approaches the cosmic mean ...
... 16% (Spergel et al. 2003). Since the Milky Way and Andromeda galaxy models only include baryons in the galactic disk and bulge components, they are far short of this value. We therefore set the Local Group medium to be 20% primordial gas, by mass, so that the entire region approaches the cosmic mean ...
Dark matter
Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but would account for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, on radiation, and on the large-scale structure of the universe. Dark matter has not been detected directly, making it one of the greatest mysteries in modern astrophysics.Dark matter neither emits nor absorbs light or any other electromagnetic radiation at any significant level. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the known universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe, while dark energy plus dark matter constitute 95.1% of the total mass–energy content of the universe.Astrophysicists hypothesized the existence of dark matter to account for discrepancies between the mass of large astronomical objects determined from their gravitational effects, and their mass as calculated from the observable matter (stars, gas, and dust) that they can be seen to contain. Their gravitational effects suggest that their masses are much greater than the observable matter survey suggests. Dark matter was postulated by Jan Oort in 1932, albeit based upon insufficient evidence, to account for the orbital velocities of stars in the Milky Way. In 1933, Fritz Zwicky was the first to use the virial theorem to infer the existence of unseen matter, which he referred to as dunkle Materie 'dark matter'. More robust evidence from galaxy rotation curves was discovered by Horace W. Babcock in 1939, but was not attributed to dark matter. The first hypothesis to postulate ""dark matter"" based upon robust evidence was formulated by Vera Rubin and Kent Ford in the 1960s–1970s, using galaxy rotation curves. Subsequently, many other observations have indicated the presence of dark matter in the universe, including gravitational lensing of background objects by galaxy clusters such as the Bullet Cluster, the temperature distribution of hot gas in galaxies and clusters of galaxies and, more recently, the pattern of anisotropies in the cosmic microwave background. According to consensus among cosmologists, dark matter is composed primarily of a not yet characterized type of subatomic particle.The search for this particle, by a variety of means, is one of the major efforts in particle physics today.Although the existence of dark matter is generally accepted by the mainstream scientific community, some alternative theories of gravity have been proposed, such as MOND and TeVeS, which try to account for the anomalous observations without requiring additional matter. However, these theories cannot account for the properties of galaxy clusters.