arXiv:astro-ph/0702414v1 15 Feb 2007
... incidence and thus with the object’s position in the telescope’s focal plane. Therefore, the low-resolution spectra were used to improve the flux calibration. Some objects were observed only on the medium-resolution spectra. In these cases the varying response function was corrected using the sky sp ...
... incidence and thus with the object’s position in the telescope’s focal plane. Therefore, the low-resolution spectra were used to improve the flux calibration. Some objects were observed only on the medium-resolution spectra. In these cases the varying response function was corrected using the sky sp ...
Galaxy Assembly through Mergers
... without the people that I thank in the following lines. They have been here with me, in many ways, since the very beginning of this journey. First and foremost, I am deeply grateful to my supervisors Jarle Brinchmann and Catarina Lobo from whom I have learned much more than I can possibly grasp. Cat ...
... without the people that I thank in the following lines. They have been here with me, in many ways, since the very beginning of this journey. First and foremost, I am deeply grateful to my supervisors Jarle Brinchmann and Catarina Lobo from whom I have learned much more than I can possibly grasp. Cat ...
H-alpha Imaging of Early-type (Sa
... types to be deficient in hydrogen gas, compared to the late types. The star formation history of galaxies can be traced using the integrated Hα equivalent widths, where the Hα emission line flux is normalized by the past star formation rate through the red continuum. Kennicutt & Kent (1983) measured ...
... types to be deficient in hydrogen gas, compared to the late types. The star formation history of galaxies can be traced using the integrated Hα equivalent widths, where the Hα emission line flux is normalized by the past star formation rate through the red continuum. Kennicutt & Kent (1983) measured ...
1 Globular Cluster Systems - McMaster Physics and Astronomy
... size is 4.6 arcmin (or 33 parsecs) across and the image resolution (\seeing") is 0.5 arcsec. Right panel: A globular cluster in the halo of the giant elliptical galaxy NGC 5128, 3900 kiloparsecs from the Milky Way. The picture shown is an I band image taken with the Hubble Space Telescope (see G. Ha ...
... size is 4.6 arcmin (or 33 parsecs) across and the image resolution (\seeing") is 0.5 arcsec. Right panel: A globular cluster in the halo of the giant elliptical galaxy NGC 5128, 3900 kiloparsecs from the Milky Way. The picture shown is an I band image taken with the Hubble Space Telescope (see G. Ha ...
Niraj D. Welikala Thesis - D-Scholarship@Pitt
... and on these scales the density fluctuations are small in size (rms fluctuations of the order ∼ 0.1 at 1 Gpc). However, on scales of the order of 10 Mpc, the density fluctuations are large (∼ 1). The most apparent overdensities are therefore on small scales, less than 10 Mpc which are the typical sc ...
... and on these scales the density fluctuations are small in size (rms fluctuations of the order ∼ 0.1 at 1 Gpc). However, on scales of the order of 10 Mpc, the density fluctuations are large (∼ 1). The most apparent overdensities are therefore on small scales, less than 10 Mpc which are the typical sc ...
Modeling Spatially and Spectrally Resolved Observations to
... This thesis owes much to the support of my officemate, Zach Berta, for five years of advice on life, computers, and astronomy. I thank Diego Muñoz, Robert Harris, Ragnhild Lunnan, and Sarah Rugheimer for countless snack and coffee breaks; Wen-fai Fong and Nick Stone for leading camping trips and t ...
... This thesis owes much to the support of my officemate, Zach Berta, for five years of advice on life, computers, and astronomy. I thank Diego Muñoz, Robert Harris, Ragnhild Lunnan, and Sarah Rugheimer for countless snack and coffee breaks; Wen-fai Fong and Nick Stone for leading camping trips and t ...
Galaxy Formation and Evolution.
... H O U J U N M O is Professor of Astrophysics at the University of Massachusetts. He is known for his work on the formation and clustering of galaxies and their dark matter halos. F R A N K VA N D E N B O S C H is Assistant Professor at Yale University, and is known for his studies of the formation, ...
... H O U J U N M O is Professor of Astrophysics at the University of Massachusetts. He is known for his work on the formation and clustering of galaxies and their dark matter halos. F R A N K VA N D E N B O S C H is Assistant Professor at Yale University, and is known for his studies of the formation, ...
Galaxy And Mass Assembly (GAMA): Gas Fuelling of Spiral Galaxies
... ∼ 1012 M (Moster et al. 2010; Behroozi et al. 2013). Thus, regardless of the exact underlying cause, 1012 M represents a critical mass in understanding environment dependent galaxy evolution and gas-fuelling in particular. In addition to centrals, the hierarchical formation of large-scale structur ...
... ∼ 1012 M (Moster et al. 2010; Behroozi et al. 2013). Thus, regardless of the exact underlying cause, 1012 M represents a critical mass in understanding environment dependent galaxy evolution and gas-fuelling in particular. In addition to centrals, the hierarchical formation of large-scale structur ...
ROSAT Ian R. Stevens* and David K. Strickland*
... compare the X-ray properties of these galaxies. The sample of EL galaxies is small, with only a total of nine in both classes listed by Conti (1991).2 Of these only one has been observed with the ROSAT PSPC: IRAS 0833+6517 (an EL galaxy with no He II l4686). We discuss the X-ray properties of IRAS 0 ...
... compare the X-ray properties of these galaxies. The sample of EL galaxies is small, with only a total of nine in both classes listed by Conti (1991).2 Of these only one has been observed with the ROSAT PSPC: IRAS 0833+6517 (an EL galaxy with no He II l4686). We discuss the X-ray properties of IRAS 0 ...
Galaxy Evolution Over the Past Eleven Billion Years: Mergers and
... surveys. Their stellar populations, characterized using deep near-infrared photometric and spectroscopic observations, reveal that they are the most massive and evolved galaxies at early epochs. This suggests that they have undergone a rapid build-up of stellar mass followed by a short-lived, effect ...
... surveys. Their stellar populations, characterized using deep near-infrared photometric and spectroscopic observations, reveal that they are the most massive and evolved galaxies at early epochs. This suggests that they have undergone a rapid build-up of stellar mass followed by a short-lived, effect ...
AGN host galaxies at redshift z ≈ 0.7: peculiar or not?
... To accurately determine the H/N ratios and the structural properties of the AGN host galaxies, we utilized the GALFIT package (Peng et al. 2002). GALFIT allows multi-component fitting of galaxy images in a χ2 minimization approach. For the decomposition of the AGN images, the individually constructe ...
... To accurately determine the H/N ratios and the structural properties of the AGN host galaxies, we utilized the GALFIT package (Peng et al. 2002). GALFIT allows multi-component fitting of galaxy images in a χ2 minimization approach. For the decomposition of the AGN images, the individually constructe ...
Catalogues of isolated galaxies, isolated pairs, and isolated triplets
... photometric-only catalogues of galaxies presents a large uncertainty introduced by projection effects. For instance, in a previous work (Argudo-Fernández et al. 2014), we describe the 3D environment for a sample of 386 galaxies in the CIG using the Ninth Data Release of the SDSS (DR9; Ahn et al. 20 ...
... photometric-only catalogues of galaxies presents a large uncertainty introduced by projection effects. For instance, in a previous work (Argudo-Fernández et al. 2014), we describe the 3D environment for a sample of 386 galaxies in the CIG using the Ninth Data Release of the SDSS (DR9; Ahn et al. 20 ...
Observational Studies of Interacting Galaxies and the Development
... understanding of galaxy merger evolution through both observational studies and instrument developments. Observationally, I approach the goal photometrically and spectroscopically. The photometric studies better constrain the number density evolution of wet and dry mergers through five CFHTLS broad ...
... understanding of galaxy merger evolution through both observational studies and instrument developments. Observationally, I approach the goal photometrically and spectroscopically. The photometric studies better constrain the number density evolution of wet and dry mergers through five CFHTLS broad ...
environmental effects on galaxy evolution in nearby clusters
... The environmental effects on galaxy evolution in nearby clusters are investigated using a multiwavelength dataset. The present analysis is focused on the properties of three (Abell 1367, Virgo and Coma) among the best studied clusters in the local Universe. Due to the variety of their environmental ...
... The environmental effects on galaxy evolution in nearby clusters are investigated using a multiwavelength dataset. The present analysis is focused on the properties of three (Abell 1367, Virgo and Coma) among the best studied clusters in the local Universe. Due to the variety of their environmental ...
COMPACT GROUPS OF GALAXIES
... Even if the discordant galaxies are ignored, the velocity dispersions of these systems are generally higher than would be expected given their visible mass (Burbidge & Burbidge 1959, 1961b, 1961c, Burbidge & Sargent 1971). It was argued that such groups must be unbound and disrupting (e.g. Ambartsum ...
... Even if the discordant galaxies are ignored, the velocity dispersions of these systems are generally higher than would be expected given their visible mass (Burbidge & Burbidge 1959, 1961b, 1961c, Burbidge & Sargent 1971). It was argued that such groups must be unbound and disrupting (e.g. Ambartsum ...
The Evolution of Star Formation Activity in . Cory R. Wagner
... In this thesis, we explore 7.5 billion years of evolution in cluster galaxy star formation activity using a sample of 11 high-redshift (1 < z < 1.5) clusters from the IRAC Shallow Cluster Survey, and 25 low-redshift (0.15 < z < 1) clusters from The Cluster Lensing And Supernova survey with Hubble. W ...
... In this thesis, we explore 7.5 billion years of evolution in cluster galaxy star formation activity using a sample of 11 high-redshift (1 < z < 1.5) clusters from the IRAC Shallow Cluster Survey, and 25 low-redshift (0.15 < z < 1) clusters from The Cluster Lensing And Supernova survey with Hubble. W ...
The correlation between galaxy morphology and star
... et al. 2010; Cassata et al. 2010). The number density of these galaxies rapidly increases, by a factor of five, from z ∼ 2 to z ∼ 1, and they are up to 5 times more compact in size than local ones with similar mass (Cassata et al. 2011, 2013). Recent works have suggested, however, that a large fract ...
... et al. 2010; Cassata et al. 2010). The number density of these galaxies rapidly increases, by a factor of five, from z ∼ 2 to z ∼ 1, and they are up to 5 times more compact in size than local ones with similar mass (Cassata et al. 2011, 2013). Recent works have suggested, however, that a large fract ...
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.