Recent star formation in local, morphologically disturbed
... of nearby early-types clearly require RSF (see section 6.2 in K07). These results indicate that early types of all luminosities form stars over the lifetime of the Universe, with massive systems accumulating 10–15 per cent of their stars since z ∼ 1, plausibly through minor mergers with small, gas-r ...
... of nearby early-types clearly require RSF (see section 6.2 in K07). These results indicate that early types of all luminosities form stars over the lifetime of the Universe, with massive systems accumulating 10–15 per cent of their stars since z ∼ 1, plausibly through minor mergers with small, gas-r ...
The life-cycle of star formation in distant clusters
... necessarily approximate, returns the correct proportions of galaxies in various stages of the star formation cycle in terms of both spectral and colour properties. Hubble Space Telescope (HST) images for the three clusters indicate that a high proportion of the active members show signs of interacti ...
... necessarily approximate, returns the correct proportions of galaxies in various stages of the star formation cycle in terms of both spectral and colour properties. Hubble Space Telescope (HST) images for the three clusters indicate that a high proportion of the active members show signs of interacti ...
A Zoo of Galaxies
... and the “blue cloud”, with a sparsely populated “green valley” in between (e.g. a fraction of the galaxies of the SDSS Main Galaxy Sample are shown on this diagram in Fig 6). This diagram demonstrates a general trend among galaxies that bigger (or intrinsically brighter) galaxies tend to be opticall ...
... and the “blue cloud”, with a sparsely populated “green valley” in between (e.g. a fraction of the galaxies of the SDSS Main Galaxy Sample are shown on this diagram in Fig 6). This diagram demonstrates a general trend among galaxies that bigger (or intrinsically brighter) galaxies tend to be opticall ...
HEPAP Subpanel
... The development of this underground facility and its associated surface facilities is funded by ~$50M from various resources in Canada and in the Province of Ontario. SNOLAB will be developed near the existing SNO experiment with a joint clean area encompassing the full facility. The establishment o ...
... The development of this underground facility and its associated surface facilities is funded by ~$50M from various resources in Canada and in the Province of Ontario. SNOLAB will be developed near the existing SNO experiment with a joint clean area encompassing the full facility. The establishment o ...
The UV properties of E+ A galaxies: constraints on feedback
... Numerous authors have studied E+A galaxies using a variety of indicators, which allows us to infer the characteristics of the (recent) starburst that dominates the spectra of these systems. While the age of the burst should be approximately ∼ 1 Gyr, simply by virtue of A-type stars being present, th ...
... Numerous authors have studied E+A galaxies using a variety of indicators, which allows us to infer the characteristics of the (recent) starburst that dominates the spectra of these systems. While the age of the burst should be approximately ∼ 1 Gyr, simply by virtue of A-type stars being present, th ...
3 science case - Giant Magellan Telescope Organization
... allow detailed dissection of individual systems. Similar techniques will allow extensions of black hole bulge mass studies to intermediate and high redshifts, probing the era of quasar growth. The GMT highresolution spectrographs will probe the reionization epoch using z > 6 AGN discovered in large ...
... allow detailed dissection of individual systems. Similar techniques will allow extensions of black hole bulge mass studies to intermediate and high redshifts, probing the era of quasar growth. The GMT highresolution spectrographs will probe the reionization epoch using z > 6 AGN discovered in large ...
The Space Density of Spiral Galaxies as f(magnitude, size and
... epoch models are needed to explain the metallicity dependence on total luminosity of the galaxy • Small burst of star formation explains the scatter on the observed relations • What about masses instead of luminosities? ...
... epoch models are needed to explain the metallicity dependence on total luminosity of the galaxy • Small burst of star formation explains the scatter on the observed relations • What about masses instead of luminosities? ...
FIELD GALAXIES AND THEIR AGNs: NATURE VERSUS
... are regions of space almost totally devoid of galaxies and their are high density regions. Cosmic Microwave Background (CMB) spectrum tells us that some regions of Universe are overdense. That is where dark matter collapses to form halos first. As these regions have higher density, the gravity they ...
... are regions of space almost totally devoid of galaxies and their are high density regions. Cosmic Microwave Background (CMB) spectrum tells us that some regions of Universe are overdense. That is where dark matter collapses to form halos first. As these regions have higher density, the gravity they ...
A photometrically and spectroscopically confirmed
... photometry here, as a large number of our galaxies do not have significant detections in this band. Galaxy NGC 0015 NGC 0109 PGC 001683 IC 0022 NGC 0345 ...
... photometry here, as a large number of our galaxies do not have significant detections in this band. Galaxy NGC 0015 NGC 0109 PGC 001683 IC 0022 NGC 0345 ...
Chapter 1
... ratios are higher than a cooler nebula. This is because to produce [O iii] λ4363 an electron needs to be excited to 5.3 eV, which requires more energy than for 4959/5007 which result from decay from 1 D2 level, 2.5 eV above the ground-state (see Figure 2.2). Therefore, these ratios can be used to co ...
... ratios are higher than a cooler nebula. This is because to produce [O iii] λ4363 an electron needs to be excited to 5.3 eV, which requires more energy than for 4959/5007 which result from decay from 1 D2 level, 2.5 eV above the ground-state (see Figure 2.2). Therefore, these ratios can be used to co ...
Giant Low Surface Brightness Galaxies
... the gas is far more extended than the stellar disks (Pickering et al. 1997; de Blok et al. 1995). But although the HI masses are large, the HI gas surface densities in M pc−2 are much lower than that of normal late type spirals (de Blok et al. 1996). The thinness of the HI distribution has import ...
... the gas is far more extended than the stellar disks (Pickering et al. 1997; de Blok et al. 1995). But although the HI masses are large, the HI gas surface densities in M pc−2 are much lower than that of normal late type spirals (de Blok et al. 1996). The thinness of the HI distribution has import ...
Investigating the Effects of Milky Way Globular Clusters
... Dark matter is believed to be matter that gives off so little light, if any at all, that we are unable to detect its presence (Weintraub 261). However, scientists have been able to infer its existence from numerous observations and calculations surrounding the nature of the Milky Way galaxy, oth ...
... Dark matter is believed to be matter that gives off so little light, if any at all, that we are unable to detect its presence (Weintraub 261). However, scientists have been able to infer its existence from numerous observations and calculations surrounding the nature of the Milky Way galaxy, oth ...
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.