Astronomy 401 Lecture 18 Galaxy Interactions Here we briefly
... Now we’ll consider another gravitational effect, one that is important to satellite galaxies, globular clusters, and general interactions of small galaxies with large ones. Consider a small galaxy or cluster of mass M moving through an infinite collection of stars, gas clouds and dark matter, with c ...
... Now we’ll consider another gravitational effect, one that is important to satellite galaxies, globular clusters, and general interactions of small galaxies with large ones. Consider a small galaxy or cluster of mass M moving through an infinite collection of stars, gas clouds and dark matter, with c ...
81 KB - CSIRO Publishing
... II. Contains Stars An additional key requirement is that a galaxy be a stellar system, (i.e. it must include some stars). In the case of recently discovered ultra-faint dwarf spheroidal galaxies, the number of stars inferred can be as low as a few hundred. It is possible, and indeed predicted by som ...
... II. Contains Stars An additional key requirement is that a galaxy be a stellar system, (i.e. it must include some stars). In the case of recently discovered ultra-faint dwarf spheroidal galaxies, the number of stars inferred can be as low as a few hundred. It is possible, and indeed predicted by som ...
Measuring the Rotational Speed of Spiral Galaxies and
... shift, Vrecession is how fast the galaxy is moving away from us, and sin(i) is the sine of the inclination angle i of the galaxy. The inclination angle is a measure of how close to edge-on you are viewing a galaxy. A galaxy viewed face-on (like looking straight down at a dinner plate) has i = 0º; a ...
... shift, Vrecession is how fast the galaxy is moving away from us, and sin(i) is the sine of the inclination angle i of the galaxy. The inclination angle is a measure of how close to edge-on you are viewing a galaxy. A galaxy viewed face-on (like looking straight down at a dinner plate) has i = 0º; a ...
Measuring the Rotational Speed of Spiral Galaxies and
... shift, Vrecession is how fast the galaxy is moving away from us, and sin(i) is the sine of the inclination angle i of the galaxy. The inclination angle is a measure of how close to edge-on you are viewing a galaxy. A galaxy viewed face-on (like looking straight down at a plate) has i = 0º; a galaxy ...
... shift, Vrecession is how fast the galaxy is moving away from us, and sin(i) is the sine of the inclination angle i of the galaxy. The inclination angle is a measure of how close to edge-on you are viewing a galaxy. A galaxy viewed face-on (like looking straight down at a plate) has i = 0º; a galaxy ...
Introduction
... dark matter; moreover, star clusters are generally found within galaxies. But denying star clusters the status of galaxies on such grounds seems somewhat arbitrary. Perhaps the best way to distinguish between star clusters and galaxies is to note that star clusters don’t exhibit much evidence of an ...
... dark matter; moreover, star clusters are generally found within galaxies. But denying star clusters the status of galaxies on such grounds seems somewhat arbitrary. Perhaps the best way to distinguish between star clusters and galaxies is to note that star clusters don’t exhibit much evidence of an ...
- EPJ Web of Conferences
... The trend in mean metallicity with system luminosity is also interesting, and full of information. The trend establishes that the present-day system luminosity is correlated tightly with system properties when the stars were forming, and the self-enrichment was being established. That was at very ea ...
... The trend in mean metallicity with system luminosity is also interesting, and full of information. The trend establishes that the present-day system luminosity is correlated tightly with system properties when the stars were forming, and the self-enrichment was being established. That was at very ea ...
Document
... the fluid that are represented by each particle are distributed smoothly in space around the particle. Then, the value of each relevant quantity (in most cases only density), for any given position, is calculated by adding the contribution of all SPH particles that are close enough to have significa ...
... the fluid that are represented by each particle are distributed smoothly in space around the particle. Then, the value of each relevant quantity (in most cases only density), for any given position, is calculated by adding the contribution of all SPH particles that are close enough to have significa ...
Galaxies
... actually, the stars in the galaxies do not completely lie on the same plane. As a result, the model does not consider the 3-D component of the gravitational attractive forces exerted by other stars in the galaxies. Second, the model has not considered the large halo of dark matter present in the spi ...
... actually, the stars in the galaxies do not completely lie on the same plane. As a result, the model does not consider the 3-D component of the gravitational attractive forces exerted by other stars in the galaxies. Second, the model has not considered the large halo of dark matter present in the spi ...
Manuscript - Kapteyn Astronomical Institute
... masses. Although the observed b/a is not a measurement of the intrinsic shape of the disk, if one assumes random orientations on the sky, the two are directly related. In our literature search we have carefully selected isolated late-type galaxies to avoid any morphology-luminosity trend that may be ...
... masses. Although the observed b/a is not a measurement of the intrinsic shape of the disk, if one assumes random orientations on the sky, the two are directly related. In our literature search we have carefully selected isolated late-type galaxies to avoid any morphology-luminosity trend that may be ...
Octonion model of dark matter
... that matter and anti-matter [22, 23, 24] should have been created in (almost) equal amounts, which would have annihilated each other as the universe cooled. Thus, in astronomy and cosmology, dark matter is matter that is inferred to exist from gravitational effects on visible matter and background r ...
... that matter and anti-matter [22, 23, 24] should have been created in (almost) equal amounts, which would have annihilated each other as the universe cooled. Thus, in astronomy and cosmology, dark matter is matter that is inferred to exist from gravitational effects on visible matter and background r ...
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.