Post-starburst galaxies: more than just an interesting curiosity
... be determined. What physical mechanisms cause a galaxy to stop forming stars, to turn into a spheroid, and thus to enter the red sequence? There are many competing theories which address one or both of these problems. Hot gas stripping (sometimes called strangulation) of small galaxies as they fall ...
... be determined. What physical mechanisms cause a galaxy to stop forming stars, to turn into a spheroid, and thus to enter the red sequence? There are many competing theories which address one or both of these problems. Hot gas stripping (sometimes called strangulation) of small galaxies as they fall ...
Article PDF - IOPscience
... and broadband colors with the clumpiness parameter S, the uniquely large asymmetries of 66 galaxies undergoing mergers, and the correlation of bulge to total light ratios, and stellar masses, with the concentration index. As an obvious goal is to use this system at high redshifts to trace evolution, ...
... and broadband colors with the clumpiness parameter S, the uniquely large asymmetries of 66 galaxies undergoing mergers, and the correlation of bulge to total light ratios, and stellar masses, with the concentration index. As an obvious goal is to use this system at high redshifts to trace evolution, ...
The Norma cluster (ACO3627) – II. The near-infrared Ks
... seem to have a steeper bright end than those without cD galaxies. Often the brightest galaxy is excluded to obtain a better fit, particularly in cD clusters. The Schechter parameters have also been found to vary depending on the region sampled within the cluster, the size of the area and the limitin ...
... seem to have a steeper bright end than those without cD galaxies. Often the brightest galaxy is excluded to obtain a better fit, particularly in cD clusters. The Schechter parameters have also been found to vary depending on the region sampled within the cluster, the size of the area and the limitin ...
2. The X-ray-Radio correlation for bulgeless galaxies
... in the previous instances, the flux is set to a logarithmic scale and has units of mJy. The majority of the sources can be found at fluxes smaller than 10 mJy......................................................................................46 Fig. 23: The flux distribution for the bulgeless sour ...
... in the previous instances, the flux is set to a logarithmic scale and has units of mJy. The majority of the sources can be found at fluxes smaller than 10 mJy......................................................................................46 Fig. 23: The flux distribution for the bulgeless sour ...
Hubble Space Telescope Imaging of Post
... Numerical simulations have successfully reproduced the physical properties of elliptical galaxies and bulges through major mergers of gas-rich disk galaxies (Granato et al. 2004; Di Matteo et al. 2005; Hopkins et al. 2006). These simulations follow star formation and BH growth simultaneously during ...
... Numerical simulations have successfully reproduced the physical properties of elliptical galaxies and bulges through major mergers of gas-rich disk galaxies (Granato et al. 2004; Di Matteo et al. 2005; Hopkins et al. 2006). These simulations follow star formation and BH growth simultaneously during ...
A CP - Indico
... Time reversal symmetry (invariance under change of time direction) does certainly not correspond to our daily experience. The macroscopic violation of T symmetry follows from maximising thermodynamic entropy (leaving a parking spot has a larger solution space than entering it). In the microscopic wo ...
... Time reversal symmetry (invariance under change of time direction) does certainly not correspond to our daily experience. The macroscopic violation of T symmetry follows from maximising thermodynamic entropy (leaving a parking spot has a larger solution space than entering it). In the microscopic wo ...
Effects of interaction on the properties of spiral galaxies. II. Isolated
... 15 isolated spiral galaxies. For some of those galaxies we also present minor axis long slit spectra and/or Hα CCD photometry. We also present long slit spectra for 4 more galaxies. The properties we have measured are compared with those of other analysis to find whether they are different. This con ...
... 15 isolated spiral galaxies. For some of those galaxies we also present minor axis long slit spectra and/or Hα CCD photometry. We also present long slit spectra for 4 more galaxies. The properties we have measured are compared with those of other analysis to find whether they are different. This con ...
AN INTENSIVE HUBBLE SPACE TELESCOPE
... ground-based surveys of SNe at low redshifts (z < 0.1). Programs such as the SDSS SN Survey (0.1 < z < 0.3; Frieman et al. 2008), the SN Legacy Survey (SNLS; Astier et al. 2006), and ESSENCE (Wood-Vasey et al. 2007; 0.3 < z < 0.8) are building samples of several hundred SNe at intermediate redshifts ...
... ground-based surveys of SNe at low redshifts (z < 0.1). Programs such as the SDSS SN Survey (0.1 < z < 0.3; Frieman et al. 2008), the SN Legacy Survey (SNLS; Astier et al. 2006), and ESSENCE (Wood-Vasey et al. 2007; 0.3 < z < 0.8) are building samples of several hundred SNe at intermediate redshifts ...
Rotation Curves of Spiral Galaxies
... nebula the ratio f of mass density to light density is found to be very high; and this conclusion holds for whatever dynamical model we consider. The spectrum of the nebula shows the characteristics of G-type dwarfs. Since f cannot be much larger than 1 for such stars, they can account for roughly o ...
... nebula the ratio f of mass density to light density is found to be very high; and this conclusion holds for whatever dynamical model we consider. The spectrum of the nebula shows the characteristics of G-type dwarfs. Since f cannot be much larger than 1 for such stars, they can account for roughly o ...
- Max-Planck-Institut für Astronomie
... incidence of major mergers between spheroid-dominated galaxies with little cold gas (dry mergers) since z ¼ 0:7. A set of N-body merger simulations was used to explore the morphological signatures of such interactions: they are recognizable either as <5 kpc separation close pairs or because of broad ...
... incidence of major mergers between spheroid-dominated galaxies with little cold gas (dry mergers) since z ¼ 0:7. A set of N-body merger simulations was used to explore the morphological signatures of such interactions: they are recognizable either as <5 kpc separation close pairs or because of broad ...
Head–tail Galaxies: beacons of high
... only viewing the radio morphology it is not possible to distinguish between a galaxy with high peculiar velocity moving through an undynamical, stationary ICM, and a galaxy with the ICM rushing past. However, spectroscopic redshifts can be used to determine the distribution of velocities for cluster ...
... only viewing the radio morphology it is not possible to distinguish between a galaxy with high peculiar velocity moving through an undynamical, stationary ICM, and a galaxy with the ICM rushing past. However, spectroscopic redshifts can be used to determine the distribution of velocities for cluster ...
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.