Chapter 5 The Evolutionary Paths Of Nearby Galaxies
... to try to understand the mechanisms behind the quenching of the star formation. I also note that a few early-type galaxies lie well outside the red sequence. These are misclassified or peculiar objects and their properties will be investigated later. To investigate whether the quenching is due to AG ...
... to try to understand the mechanisms behind the quenching of the star formation. I also note that a few early-type galaxies lie well outside the red sequence. These are misclassified or peculiar objects and their properties will be investigated later. To investigate whether the quenching is due to AG ...
Extragalactic Astronomical Masers I
... Maser pumping is thus caused by the transitions of molecules between the two different energy levels. The mechanism that causes maser pumping is thought to be either collision or external radiation (e.g., Elitzur 1992). Maser emits very intense radiation that we can see the maser emission occurring ...
... Maser pumping is thus caused by the transitions of molecules between the two different energy levels. The mechanism that causes maser pumping is thought to be either collision or external radiation (e.g., Elitzur 1992). Maser emits very intense radiation that we can see the maser emission occurring ...
THE GREAT AGN DEBATE `AGN VS STARBURST
... host galaxies can be spirals, irregulars or ellipticals: there is a correlation between the quasar's luminosity and the mass of its host galaxy, so that the most luminous quasars inhabit the most massive galaxies. 6. Ultraluminous InfraRed Galaxies (ULIRG), as defined by Sanders and Mirabel (1996) i ...
... host galaxies can be spirals, irregulars or ellipticals: there is a correlation between the quasar's luminosity and the mass of its host galaxy, so that the most luminous quasars inhabit the most massive galaxies. 6. Ultraluminous InfraRed Galaxies (ULIRG), as defined by Sanders and Mirabel (1996) i ...
Mapping the Pathways of Galaxy Transformation Across Time and
... outcomes from the IMACS Cluster-Building Survey: our finding that most z∼0.5 poststarbursts are rejuvenated passive galaxies, and a simple model positing that every galaxy has a lognormal SFH whose parameters are set at birth. Both studies reinterpreted key metrics of galaxy evolution typically seen ...
... outcomes from the IMACS Cluster-Building Survey: our finding that most z∼0.5 poststarbursts are rejuvenated passive galaxies, and a simple model positing that every galaxy has a lognormal SFH whose parameters are set at birth. Both studies reinterpreted key metrics of galaxy evolution typically seen ...
A tale of two galaxies: light and mass in NGC 891 and NGC 7814
... not known inside 1 arcmin (3−4 kpc) because H I emission was not detected there. The conclusion was that “if the distribution of luminous matter were in any way related to the total mass distribution it would not be possible for the disk-dominated and the bulge-dominated galaxies to have such simila ...
... not known inside 1 arcmin (3−4 kpc) because H I emission was not detected there. The conclusion was that “if the distribution of luminous matter were in any way related to the total mass distribution it would not be possible for the disk-dominated and the bulge-dominated galaxies to have such simila ...
What Gaia can reveal about the matter distribution in the Milky Way
... which allow more light to enter the telescope. Secondly, the detectors of Gaia are more sensitive as the used technique is CCDs and not photomultiplier tubes as on Hipparcos. Apart from the photomultiplier tubes being less efficient than CCDs are, they also had to be focussed on individual stars, wh ...
... which allow more light to enter the telescope. Secondly, the detectors of Gaia are more sensitive as the used technique is CCDs and not photomultiplier tubes as on Hipparcos. Apart from the photomultiplier tubes being less efficient than CCDs are, they also had to be focussed on individual stars, wh ...
Global structure and kinematics of stellar haloes in cosmological
... (Ferland et al. 1998) that contain cooling rates as a function of density, temperature, and redshift and that account for the presence of the cosmic microwave background and photoionisation from a Haardt & Madau (2001) ionising UV/X-Ray background (see Wiersma et al. 2009a). This background is switc ...
... (Ferland et al. 1998) that contain cooling rates as a function of density, temperature, and redshift and that account for the presence of the cosmic microwave background and photoionisation from a Haardt & Madau (2001) ionising UV/X-Ray background (see Wiersma et al. 2009a). This background is switc ...
Mirror particles and mirror matter: 50 years of speculation and search
... particles and of a mirror world. (The modern terminology, in which mirror matter refers only to duplication of all our particles (not some of them) was in statu nascendi, therefore the “mirror world” and “mirror particles” were used in [39] practically as synonyms. Note that the Standard Model did n ...
... particles and of a mirror world. (The modern terminology, in which mirror matter refers only to duplication of all our particles (not some of them) was in statu nascendi, therefore the “mirror world” and “mirror particles” were used in [39] practically as synonyms. Note that the Standard Model did n ...
A UV study of nearby luminous infrared galaxies: star formation
... Both dust obscuration and the strength of star formation activity is likely to evolve with increasing look-back time and similar plots from high-redshift surveys are keenly anticipated. Finally, we note some points regarding the SDSS and GALEX data that underpin this study. A potential concern for o ...
... Both dust obscuration and the strength of star formation activity is likely to evolve with increasing look-back time and similar plots from high-redshift surveys are keenly anticipated. Finally, we note some points regarding the SDSS and GALEX data that underpin this study. A potential concern for o ...
X. Nuclear star clusters in low-mass early-type galaxies
... formation mechanisms, most of which are analytically derived. One of the few qualitative predictions for the relation between NSC mass and host galaxy velocity dispersion for in situ formation is given by McLaughlin, King & Nayakshin (2006), where it is assumed that the winds from giant stars and su ...
... formation mechanisms, most of which are analytically derived. One of the few qualitative predictions for the relation between NSC mass and host galaxy velocity dispersion for in situ formation is given by McLaughlin, King & Nayakshin (2006), where it is assumed that the winds from giant stars and su ...
Stellar Populations of Dwarf Elliptical Galaxies: UBVRI Photometry
... UBVRI images of 16 dwarf elliptical galaxies in the Virgo Cluster were obtained with the VATT 1.8m on 2003 March 29-31. The telescope was equipped with CCD26, a thinned Loral 3 2048 × 2048 CCD with 15µm pixels. CCD26 has a read noise of 5.7 e− and a gain of 1.9 e− per ADU was used. On-chip binning o ...
... UBVRI images of 16 dwarf elliptical galaxies in the Virgo Cluster were obtained with the VATT 1.8m on 2003 March 29-31. The telescope was equipped with CCD26, a thinned Loral 3 2048 × 2048 CCD with 15µm pixels. CCD26 has a read noise of 5.7 e− and a gain of 1.9 e− per ADU was used. On-chip binning o ...
The MUSIC of galaxy clusters – I. Baryon properties and scaling
... mock observations for X-rays, SZ, lensing as well as optical galaxy counts. This will allow us to study the interrelations between the scaling laws associated with the different observables. In this paper we base our attention on the properties of the baryon content and the SZ effects and will leave ...
... mock observations for X-rays, SZ, lensing as well as optical galaxy counts. This will allow us to study the interrelations between the scaling laws associated with the different observables. In this paper we base our attention on the properties of the baryon content and the SZ effects and will leave ...
A subaru/suprime-cam wide
... (1) Most of the blue GCs are associated with the host galaxy, not the host galaxy cluster, even in central cluster galaxies like M87. (2) Blue GCs may be linked with the dark matter halo of a massive elliptical galaxy: they might have formed in sub-galactic clumps and assembled thereafter, whilst re ...
... (1) Most of the blue GCs are associated with the host galaxy, not the host galaxy cluster, even in central cluster galaxies like M87. (2) Blue GCs may be linked with the dark matter halo of a massive elliptical galaxy: they might have formed in sub-galactic clumps and assembled thereafter, whilst re ...
A numerical study of recent tidal interactions between dwarf galaxies
... These simulations demonstrated that the presence of a Milky Way-like dark matter halo has an influence on the evolution of the dwarf galaxies. In all studies tidal stripping and tidal tails were observed. These interactions also led to star formation bursts in the dwarf galaxies. And there was stat ...
... These simulations demonstrated that the presence of a Milky Way-like dark matter halo has an influence on the evolution of the dwarf galaxies. In all studies tidal stripping and tidal tails were observed. These interactions also led to star formation bursts in the dwarf galaxies. And there was stat ...
THE EVOLUTION OF GALAXY NUMBER DENSITY AT Z < 8 AND
... There are a few reasons for why deep imaging programs are not easily able to convert observations to total numbers of galaxies. One of these issues is that all deep observations are incomplete. This is due to limitations in exposure times and depth such that certain galaxies will be detected more re ...
... There are a few reasons for why deep imaging programs are not easily able to convert observations to total numbers of galaxies. One of these issues is that all deep observations are incomplete. This is due to limitations in exposure times and depth such that certain galaxies will be detected more re ...
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.