normal and active - FirstLight Astro
... 1. Which galaxy type varies the most in size? 2. Which can be enormously bigger than our galaxy? 3. Which make up the tiniest group overall? 4. What “stuff” is making the whole process of knowing galactic properties more difficult? ...
... 1. Which galaxy type varies the most in size? 2. Which can be enormously bigger than our galaxy? 3. Which make up the tiniest group overall? 4. What “stuff” is making the whole process of knowing galactic properties more difficult? ...
Institute for Astrophysical Research Seminar Series
... Steven Snowden (NASA Goddard Space Flight Center) The Diffuse X-ray Background, from Earth's Exosphere to the Edge of the Universe OR One Astronomer's Signal is Another Astronomer's Contamination ...
... Steven Snowden (NASA Goddard Space Flight Center) The Diffuse X-ray Background, from Earth's Exosphere to the Edge of the Universe OR One Astronomer's Signal is Another Astronomer's Contamination ...
November - Hawaiian Astronomical Society
... DUNES, DEBRIS. For the time being, the scientists on these teams are the only ones with access to the Herschel data. But in January, all the data these teams are working on will suddenly be released to the public. So they are all under pressure to finish their work by then. The team whose meeting I ...
... DUNES, DEBRIS. For the time being, the scientists on these teams are the only ones with access to the Herschel data. But in January, all the data these teams are working on will suddenly be released to the public. So they are all under pressure to finish their work by then. The team whose meeting I ...
The chemical enrichment of the ICM from hydrodynamical simulations
... A number of authors have presented hydrodynamical simulations for the formation of cosmic structures, which include treatments of the chemical evolution at different levels of complexity. Raiteri et al. (1996) presented SPH simulations of the Galaxy, forming in an isolated halo, by following iron an ...
... A number of authors have presented hydrodynamical simulations for the formation of cosmic structures, which include treatments of the chemical evolution at different levels of complexity. Raiteri et al. (1996) presented SPH simulations of the Galaxy, forming in an isolated halo, by following iron an ...
Spiral Arms - Harry Kroto
... that the spiral continues wind up tighter and tigher. In only a few revolutions the spiral gets extremely wound up. At its distance from the Galactic Center the Sun has gone around the Galaxy around 18 times. In so many turns the spiral pattern would be extremely wound up. This is not the case and s ...
... that the spiral continues wind up tighter and tigher. In only a few revolutions the spiral gets extremely wound up. At its distance from the Galactic Center the Sun has gone around the Galaxy around 18 times. In so many turns the spiral pattern would be extremely wound up. This is not the case and s ...
Our galaxy - School of Physics
... width is hard to define because it does not have sharp boundaries. Stars like the Sun lie within 500 pc above and below the central plane; the youngest stars lie within 50 pc. ...
... width is hard to define because it does not have sharp boundaries. Stars like the Sun lie within 500 pc above and below the central plane; the youngest stars lie within 50 pc. ...
Is Draco II one of the faintest dwarf galaxies? First study from Keck
... way to optimise the number of high-priority bright candidate members. The priorities were set as both a function of spatial location (higher priority towards the center of the system) and location in the colour-magnitude diagram (CMD). All targets are selected using the PS1 photometry and higher pri ...
... way to optimise the number of high-priority bright candidate members. The priorities were set as both a function of spatial location (higher priority towards the center of the system) and location in the colour-magnitude diagram (CMD). All targets are selected using the PS1 photometry and higher pri ...
Galaxy Formation and Evolution
... of the Universe itself down to the scale of individual stars, and about 4 orders of magnitude in time scales, from the age of the Universe to that of the lifetime of individual, massive stars. It’s a very challenging problem!! ...
... of the Universe itself down to the scale of individual stars, and about 4 orders of magnitude in time scales, from the age of the Universe to that of the lifetime of individual, massive stars. It’s a very challenging problem!! ...
Baryons at Low Densities: The Stellar Halos around Galaxies
... was largely built from one, or a few, relatively massive (> 109 MA) accretion events, but at large radii many low-mass accretions have contributed to the recent buildup of the halo. The kinematics of the inner halo stars is however consistent with their origin from the disc — these stars were likely ...
... was largely built from one, or a few, relatively massive (> 109 MA) accretion events, but at large radii many low-mass accretions have contributed to the recent buildup of the halo. The kinematics of the inner halo stars is however consistent with their origin from the disc — these stars were likely ...
Lectures 19-20 The Milky Way Galaxy
... Historical Models of the Milky Way Galaxy Jacobus Kapteyn (1851-1922) used star counting to confirm the Herschel model, but with much-improved methods. Now called the Kapteyn Universe. Galaxy consists of a flattened Spheroidal system with a decreasing stellar density with increasing distance from t ...
... Historical Models of the Milky Way Galaxy Jacobus Kapteyn (1851-1922) used star counting to confirm the Herschel model, but with much-improved methods. Now called the Kapteyn Universe. Galaxy consists of a flattened Spheroidal system with a decreasing stellar density with increasing distance from t ...
Variations in Integrated Galactic Initial Mass Functions due to
... makes it hard to infer directly from the masses. Their strong effect on the upper mass limit for the clusters in a galaxy makes it detectable from a statistical point of view, though. See below for a discussion on how Schechter-like CMFs might influence the IGIMF effect. Here we took pure power-laws ...
... makes it hard to infer directly from the masses. Their strong effect on the upper mass limit for the clusters in a galaxy makes it detectable from a statistical point of view, though. See below for a discussion on how Schechter-like CMFs might influence the IGIMF effect. Here we took pure power-laws ...
Determination of kinetic energies of stars using Hipparcos data *
... motions were established at the Hipparcos Venice’97 symposium. In particular, the questions of determining the average density (Pham, H.-A. 1997) and escape velocity (Meillon, L. et al. 1997) in the vicinity of the Sun, were discussed. Our research is along these lines. More precisely, we attempt to ...
... motions were established at the Hipparcos Venice’97 symposium. In particular, the questions of determining the average density (Pham, H.-A. 1997) and escape velocity (Meillon, L. et al. 1997) in the vicinity of the Sun, were discussed. Our research is along these lines. More precisely, we attempt to ...
Astronomy and the Coal Age of Alabama
... The Pleiades star cluster visible to the naked eye in Taurus is only 100 Myr old. It was not shining in anybody’s sky 310 Myr ago. ...
... The Pleiades star cluster visible to the naked eye in Taurus is only 100 Myr old. It was not shining in anybody’s sky 310 Myr ago. ...
Penentuan Jarak dalam Astronomi II
... These “standard candles” can be seen from the distance ~50 Mpc (with ~27m limiting magnitude accessible to HST) Brightest Cepheids can be widely used as secondary sources of distance calibrations to spiral galaxies hosted by SN Ia etc. ...
... These “standard candles” can be seen from the distance ~50 Mpc (with ~27m limiting magnitude accessible to HST) Brightest Cepheids can be widely used as secondary sources of distance calibrations to spiral galaxies hosted by SN Ia etc. ...
Pretty Pictures of the Cosmos
... with the Hubble Space Telescope, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic Tadpole is a mere 420 million light-years distant toward the northern constellation Draco. Its eye-catching tail is about 280 thousand light-years long and f ...
... with the Hubble Space Telescope, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic Tadpole is a mere 420 million light-years distant toward the northern constellation Draco. Its eye-catching tail is about 280 thousand light-years long and f ...
The Pleiades in the Salle des Taureaux", Grotte de Lascaux
... unaided eyes under the best conditions (GUNDEL, 1913: c. 2617-2618). Most reports speak of five stars, which all have the apparent brightness of between 3m.4 and 3m.8 or of six, when the star Aldebarán (0m.9), as often happened, is included (GUNDEL, 1913: c. 2618, 2622). ...
... unaided eyes under the best conditions (GUNDEL, 1913: c. 2617-2618). Most reports speak of five stars, which all have the apparent brightness of between 3m.4 and 3m.8 or of six, when the star Aldebarán (0m.9), as often happened, is included (GUNDEL, 1913: c. 2618, 2622). ...
Lecture notes 18: Galaxies and galaxy clusters
... fractions are 12% E’s, 26% S0’s, and 62% S and Ir. In the rich Coma cluster we find 44% E’s, 49% S0’s and only 7% S and Ir’s. Galactic collisions and other interactions The typical distances between galaxies is not very much larger than typical galactic dimensions and galactic collisions cannot be ig ...
... fractions are 12% E’s, 26% S0’s, and 62% S and Ir. In the rich Coma cluster we find 44% E’s, 49% S0’s and only 7% S and Ir’s. Galactic collisions and other interactions The typical distances between galaxies is not very much larger than typical galactic dimensions and galactic collisions cannot be ig ...
Article PDF - IOPscience
... Currently available evidence suggests that star formation continued much longer in many dwarf spheroidals than it did in the main body of the Galactic halo. It is suggested that ““ young ÏÏ globular clusters, such as Ruprecht 106, might have formed in now defunct dwarf spheroidals. Assuming SagDIG, ...
... Currently available evidence suggests that star formation continued much longer in many dwarf spheroidals than it did in the main body of the Galactic halo. It is suggested that ““ young ÏÏ globular clusters, such as Ruprecht 106, might have formed in now defunct dwarf spheroidals. Assuming SagDIG, ...
Ch17_Galaxies
... • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cluster together and these clusters appear to be separat ...
... • Some galaxies are spiral like the Milky Way while others are egg-shaped or completely irregular in appearance • Besides shape, galaxies vary greatly in the star, gas, and dust content and some are more “active” than others • Galaxies tend to cluster together and these clusters appear to be separat ...
Characteristics of Our Galaxy
... variables (useful for judging distances), pre-main sequence stars, T-Tauri stars, Herbigharo objects, and even some A stars can be found in the arms. These stars are very metal rich and have highly circular orbits, although they comprise likely less than one percent of Milky Way stars. Young thin d ...
... variables (useful for judging distances), pre-main sequence stars, T-Tauri stars, Herbigharo objects, and even some A stars can be found in the arms. These stars are very metal rich and have highly circular orbits, although they comprise likely less than one percent of Milky Way stars. Young thin d ...
The Milky Way
... Galaxies seem to take one of four different appearances Ellipticals have no dust No cold gas: No star formation Made mostly of old stars ...
... Galaxies seem to take one of four different appearances Ellipticals have no dust No cold gas: No star formation Made mostly of old stars ...
Review 3 (11-18-10)
... If we could view the Milky Way from above the disk, we would see its spiral arms ...
... If we could view the Milky Way from above the disk, we would see its spiral arms ...
Galaxies * Island universes
... A Galaxy’s color evolves from bluer, towards redder as stellar population ages, young blue stars die out Galaxy collisions common because they’re usually only 100 or fewer galaxy diameters apart Collisions between galaxies produce irregulars which settle into ellipticals More massive ellipticals hav ...
... A Galaxy’s color evolves from bluer, towards redder as stellar population ages, young blue stars die out Galaxy collisions common because they’re usually only 100 or fewer galaxy diameters apart Collisions between galaxies produce irregulars which settle into ellipticals More massive ellipticals hav ...
An Overview of the Gaia
... • There is secular evolution as well. • Galaxies evolved chemically, under the right conditions, since each generation of stars progressively enriches the gas. ...
... • There is secular evolution as well. • Galaxies evolved chemically, under the right conditions, since each generation of stars progressively enriches the gas. ...
Open cluster
An open cluster, also known as galactic cluster, is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist. They are loosely bound by mutual gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the galactic center, resulting in a migration to the main body of the galaxy as well as a loss of cluster members through internal close encounters. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral and irregular galaxies, in which active star formation is occurring.Young open clusters may still be contained within the molecular cloud from which they formed, illuminating it to create an H II region. Over time, radiation pressure from the cluster will disperse the molecular cloud. Typically, about 10% of the mass of a gas cloud will coalesce into stars before radiation pressure drives the rest of the gas away.Open clusters are key objects in the study of stellar evolution. Because the cluster members are of similar age and chemical composition, their properties (such as distance, age, metallicity and extinction) are more easily determined than they are for isolated stars. A number of open clusters, such as the Pleiades, Hyades or the Alpha Persei Cluster are visible with the naked eye. Some others, such as the Double Cluster, are barely perceptible without instruments, while many more can be seen using binoculars or telescopes. The Wild Duck Cluster, M11, is an example.