Globular Cluster Bimodality in Isolated Elliptical Galaxies
... Chapter 1 Introduction Astronomers try to answer questions like how did the celestial objects we see today form, how long have they been around, how have they evolved in time? Such puzzles are resolved by proposing hypothesis and models which often times do not adequately describe the entire spectr ...
... Chapter 1 Introduction Astronomers try to answer questions like how did the celestial objects we see today form, how long have they been around, how have they evolved in time? Such puzzles are resolved by proposing hypothesis and models which often times do not adequately describe the entire spectr ...
- Durham Research Online
... observations at any given wavelength is summarized in Table 1. We calibrated the data products from these surveys following the instructions provided by the respective teams. For the SDSS we used the legacy imaging data with the “best” reduction from the Data Release 7 (DR7), and for 2MASS we use th ...
... observations at any given wavelength is summarized in Table 1. We calibrated the data products from these surveys following the instructions provided by the respective teams. For the SDSS we used the legacy imaging data with the “best” reduction from the Data Release 7 (DR7), and for 2MASS we use th ...
arXiv:1601.01542v1 [astro-ph.GA] 7 Jan 2016
... Roy & Walsh 1997, among others). These features have been theoretically suggested to be motivated, for instance, by the presence of radial migration (Minchev et al. 2011, 2012). Nevertheless, their origin is still unknown. All these spectroscopic studies were limited by statistics, either in the num ...
... Roy & Walsh 1997, among others). These features have been theoretically suggested to be motivated, for instance, by the presence of radial migration (Minchev et al. 2011, 2012). Nevertheless, their origin is still unknown. All these spectroscopic studies were limited by statistics, either in the num ...
Galaxy And Mass Assembly (GAMA): Understanding the wavelength
... ellipticals and lenticulars on the Hubble tuning fork diagram (Liller 1966). They have since been referred to as E/S0 galaxies and discy ellipticals (Nieto, Capaccioli & Held 1988; Simien & Michard 1990). This view was later augmented to include parallel sequences for spirals and lenticulars, with ‘ ...
... ellipticals and lenticulars on the Hubble tuning fork diagram (Liller 1966). They have since been referred to as E/S0 galaxies and discy ellipticals (Nieto, Capaccioli & Held 1988; Simien & Michard 1990). This view was later augmented to include parallel sequences for spirals and lenticulars, with ‘ ...
T3-Cosmic Star Formation History
... 2003, Giavalisco et al. 2004a, Bouwens et al. 2011b). Infrared (IR)-optical color selection criteria efficiently isolate both actively star-forming and passively evolving galaxies at z ≈ 2 (Franx et al. 2003, Daddi et al. 2004). Photometric redshifts have become an unavoidable tool for placing faint ...
... 2003, Giavalisco et al. 2004a, Bouwens et al. 2011b). Infrared (IR)-optical color selection criteria efficiently isolate both actively star-forming and passively evolving galaxies at z ≈ 2 (Franx et al. 2003, Daddi et al. 2004). Photometric redshifts have become an unavoidable tool for placing faint ...
A deep view on the Virgo cluster core
... Virgo cluster members. The images in both bands were inspected independently from each other. A first pre-selection was based on the following selection criteria. 1. The depth of the observed data revealed many background objects. While their physical size and luminosity would typically be larger th ...
... Virgo cluster members. The images in both bands were inspected independently from each other. A first pre-selection was based on the following selection criteria. 1. The depth of the observed data revealed many background objects. While their physical size and luminosity would typically be larger th ...
Observational evidence for AGN feedback in early
... 2.3.1 Matching to GALEX The GALEX (Martin et al. 2005) is conducting several surveys of the ultraviolet sky in two filters: far-UV (FUV; 1344–1786 Å) and near-UV (NUV; 1771–2831 Å). The Medium Imaging Survey from the General Release 3 (MIS/GR3) is covering a portion of the sky coinciding with the SD ...
... 2.3.1 Matching to GALEX The GALEX (Martin et al. 2005) is conducting several surveys of the ultraviolet sky in two filters: far-UV (FUV; 1344–1786 Å) and near-UV (NUV; 1771–2831 Å). The Medium Imaging Survey from the General Release 3 (MIS/GR3) is covering a portion of the sky coinciding with the SD ...
IDEA MAN
... were beautifully spherical. But the laws of physics said that an initially chaotic group of galaxies could only become symmetrical through a series of close encounters among three or more galaxies. Since such encounters were fantastically rare, the Universe had to be at least 1018 years ...
... were beautifully spherical. But the laws of physics said that an initially chaotic group of galaxies could only become symmetrical through a series of close encounters among three or more galaxies. Since such encounters were fantastically rare, the Universe had to be at least 1018 years ...
The Physical Origins of The Morphology
... information, but for large samples it becomes a powerful diagnostic. We take advantage of the uniform and well-calibrated data set provided by the SDSS, which is ideally suited to disentangle projection effects and the intrinsic shape distribution of galaxies, as has previously been demonstrated by ...
... information, but for large samples it becomes a powerful diagnostic. We take advantage of the uniform and well-calibrated data set provided by the SDSS, which is ideally suited to disentangle projection effects and the intrinsic shape distribution of galaxies, as has previously been demonstrated by ...
Evolutionary paths among different red galaxy types at 0.3< z< 1.5
... bar at the left top corner of each frame. The figure shows the well-known bimodal distribution of galaxies into red and blue populations at all redshifts up to z ∼ 2 (see references in §1). These bimodal distributions have been modelled as the addition of two Gaussian functions (also plotted in the ...
... bar at the left top corner of each frame. The figure shows the well-known bimodal distribution of galaxies into red and blue populations at all redshifts up to z ∼ 2 (see references in §1). These bimodal distributions have been modelled as the addition of two Gaussian functions (also plotted in the ...
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 ...
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.