The formation of disc galaxies in high-resolution moving
... progressively higher mass particles whose mass grows with distance from the target galaxy. This saves computational time while still ensuring the correct cosmological tidal field and mass infall rate for the forming target galaxy. The target galaxies themselves have been selected randomly from a sma ...
... progressively higher mass particles whose mass grows with distance from the target galaxy. This saves computational time while still ensuring the correct cosmological tidal field and mass infall rate for the forming target galaxy. The target galaxies themselves have been selected randomly from a sma ...
A Comet-Hunter`s Legacy -
... by each other, they undergo episodes of star formation caused by their gravitational interaction. M81's bright spiral arms are the site of star formation, partially caused by density waves raised by the most recent passage of M82, and the central portion of M82 is undergoing a starburst -- an explos ...
... by each other, they undergo episodes of star formation caused by their gravitational interaction. M81's bright spiral arms are the site of star formation, partially caused by density waves raised by the most recent passage of M82, and the central portion of M82 is undergoing a starburst -- an explos ...
The Formation and Evolution of the Milky Way
... is located in the halo. It is old and has a metallicity [Fe/H] of about -4.0, or about 10,000 times less than the Sun! That it happens to be an ancient star is not a coincidence. When it was born the stellar chemical factories were only just beginning to start operation, so there was simply not a gr ...
... is located in the halo. It is old and has a metallicity [Fe/H] of about -4.0, or about 10,000 times less than the Sun! That it happens to be an ancient star is not a coincidence. When it was born the stellar chemical factories were only just beginning to start operation, so there was simply not a gr ...
What are Messier Objects? - Bowling Green State University
... Is one of the brightest starforming nebulae and one of the brightest diffusion nebulae in the sky It is a big object, considered to cover four times the area of the full moon. Located 1,600 light years away. Is a very turbulent cloud of gas and dust, hence it’s ...
... Is one of the brightest starforming nebulae and one of the brightest diffusion nebulae in the sky It is a big object, considered to cover four times the area of the full moon. Located 1,600 light years away. Is a very turbulent cloud of gas and dust, hence it’s ...
Lecture 9: The interstellar medium (ISM)
... and HI high velocity clouds represent weak sources of 21-cm emission located well away from the galactic plane. They are the result of tidal interation of the Galaxy on the satellite galaxies, the Magellanic Clouds. ...
... and HI high velocity clouds represent weak sources of 21-cm emission located well away from the galactic plane. They are the result of tidal interation of the Galaxy on the satellite galaxies, the Magellanic Clouds. ...
Full-text PDF
... 2003). In this paper we argue that radio sources may provide the required feedback while at the same time providing a solution to two other long-standing puzzles. An important unanswered question is why the gas at the centre of most galaxy clusters is apparently not condensing and turning into stars ...
... 2003). In this paper we argue that radio sources may provide the required feedback while at the same time providing a solution to two other long-standing puzzles. An important unanswered question is why the gas at the centre of most galaxy clusters is apparently not condensing and turning into stars ...
A GMOS dissection of the line-of
... Absorber has metal-bearing gas, with column densities up to 1017 cm-2 in MgII. Where is the gas located? Could originate in outer halo of nearby galaxy. Nearest confirmed galaxy is 50kpc from line-of-sight, so quasar is likely to be still in the halo. ...
... Absorber has metal-bearing gas, with column densities up to 1017 cm-2 in MgII. Where is the gas located? Could originate in outer halo of nearby galaxy. Nearest confirmed galaxy is 50kpc from line-of-sight, so quasar is likely to be still in the halo. ...
The fate of black hole singularities and the parameters of the
... fact that our universe is as structured as it apparently is, from the scales of galaxies to the existence of many stable nuclei, and hence stars and chemistry, is based on a series of apparent coincidences relating the values of the fundamental dimensionless parameters of physics and cosmology. For ...
... fact that our universe is as structured as it apparently is, from the scales of galaxies to the existence of many stable nuclei, and hence stars and chemistry, is based on a series of apparent coincidences relating the values of the fundamental dimensionless parameters of physics and cosmology. For ...
Stellar populations
... • About 400 known; ~18000 may exist in Galaxy • Gal. latitude b ≤ 5º in most cases, very few >10º • Open clusters are mainly young Popn I objects • Typically they contain a few hundred stars • The stars are coeval (of same age), at essentially same distance and of same metallicity • There is a sprea ...
... • About 400 known; ~18000 may exist in Galaxy • Gal. latitude b ≤ 5º in most cases, very few >10º • Open clusters are mainly young Popn I objects • Typically they contain a few hundred stars • The stars are coeval (of same age), at essentially same distance and of same metallicity • There is a sprea ...
On the Spiral Structure of the Milky Way Galaxy
... The spiral pattern in ``grand-design'' galaxies is strictly symmetrical with respect of rotation around the galaxy center by 180° (this was demonstrated especially evidently for M51 [17]), and if a second pair of arms is present, these arms are located between the two arms of the first pair. Thus, i ...
... The spiral pattern in ``grand-design'' galaxies is strictly symmetrical with respect of rotation around the galaxy center by 180° (this was demonstrated especially evidently for M51 [17]), and if a second pair of arms is present, these arms are located between the two arms of the first pair. Thus, i ...
Stars and Galaxies - Red Hook Central Schools
... http://hubblesite.org/newscenter/archive/releases/star/supernova/2004/09/results/50/ http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/ http://chandra.harvard.edu/photo/2009/casa/ ...
... http://hubblesite.org/newscenter/archive/releases/star/supernova/2004/09/results/50/ http://hubblesite.org/newscenter/archive/releases/nebula/supernova-remnant/2005/37/results/50/ http://chandra.harvard.edu/photo/2009/casa/ ...
Dynamical properties of a large young disk galaxy at z=2.03⋆
... Starting with density fluctuations in the early universe, dark matter halos grow through gravity. Galaxy formation is described by semi-analytical models or hydrodynamical simulations. These may include physical processes such as gas cooling, star formation, feedback from stellar winds, supernovae a ...
... Starting with density fluctuations in the early universe, dark matter halos grow through gravity. Galaxy formation is described by semi-analytical models or hydrodynamical simulations. These may include physical processes such as gas cooling, star formation, feedback from stellar winds, supernovae a ...
The Milky Way thin disk structure as revealed by stars and young
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
... when seen face-off, possess dusty and gaseous disks where stars are barely visible. On the other hand, when seen face-on, they exhibit quite spectacular structures in the form of gaseous and stellar spiral arms, bridges, inter-arm structures, knots, bifurcations, and so forth. These detailed shapes a ...
Deep Sky Catalogues, the New Uranometria and Other Stories
... chosen definitions (see next criterion). Clearly defined object classes and selection criteria. The „optical“ object classes should be contained: open and globular clusters, emission-, reflection- and dark nebulae, planetary nebulae, galaxies (including quasars) and clusters of galaxies. If there is ...
... chosen definitions (see next criterion). Clearly defined object classes and selection criteria. The „optical“ object classes should be contained: open and globular clusters, emission-, reflection- and dark nebulae, planetary nebulae, galaxies (including quasars) and clusters of galaxies. If there is ...
Summary of Talks at Growing Black Holes 2004 in Garching
... -> High resolution CO observations of the object resolve it spatially into two peaks. It also resolved in velocity space, with a CO line width of 280 km/s and a bulge mass estimate of 1e10 solar masses within 2kpc, which is lower than expected from M sigma relation. Is this object not fully assemble ...
... -> High resolution CO observations of the object resolve it spatially into two peaks. It also resolved in velocity space, with a CO line width of 280 km/s and a bulge mass estimate of 1e10 solar masses within 2kpc, which is lower than expected from M sigma relation. Is this object not fully assemble ...
Suppose you tried to determine where we are in the galaxy by
... a) We're in the middle of one of its arms and thus have no perspective. b) It is very large and the edges are far away and faint. c) Dust blocks our view when we look toward the center or in the disk. d) We cannot see it from the outside. e) all of the above ...
... a) We're in the middle of one of its arms and thus have no perspective. b) It is very large and the edges are far away and faint. c) Dust blocks our view when we look toward the center or in the disk. d) We cannot see it from the outside. e) all of the above ...
Astronomical Picture of the Day
... The Orion Nebula (a) is a giant cloud of gas and dust in which new stars and planets are forming. It is located about 1,500 light-years from Earth, which means the light recorded in the photograph took about 1,500 years to reach us. Thus, we see it as it was about 1,500 years ago. Photograph (b) sho ...
... The Orion Nebula (a) is a giant cloud of gas and dust in which new stars and planets are forming. It is located about 1,500 light-years from Earth, which means the light recorded in the photograph took about 1,500 years to reach us. Thus, we see it as it was about 1,500 years ago. Photograph (b) sho ...
Downloadable Full Text
... primarily from rare events like neutron star mergers5,6. The appearance of a europium abundance plateau in some dwarf spheroidal galaxies was suggested as evidence for rare rprocess enrichment in the early universe7, but only under the assumption of no gas accretion into the dwarf galaxies. Invoking ...
... primarily from rare events like neutron star mergers5,6. The appearance of a europium abundance plateau in some dwarf spheroidal galaxies was suggested as evidence for rare rprocess enrichment in the early universe7, but only under the assumption of no gas accretion into the dwarf galaxies. Invoking ...
Carbon-enhanced metal-poor stars in dwarf galaxies
... From Fig. 1 we can note that stars at [Fe/H]≤ −4.5 have only been found in the Galactic halo. Moreover, we can see that the frequency of CEMP-no stars among these “hyper-iron-poor stars” is extremely high: 8 out of 9 stars at [Fe/H]≤ −4.5 are CEMP-no stars. These objects have peculiar chemical abund ...
... From Fig. 1 we can note that stars at [Fe/H]≤ −4.5 have only been found in the Galactic halo. Moreover, we can see that the frequency of CEMP-no stars among these “hyper-iron-poor stars” is extremely high: 8 out of 9 stars at [Fe/H]≤ −4.5 are CEMP-no stars. These objects have peculiar chemical abund ...
WELCOME TO THE MILKY WAY
... the Sun. In fact all the stars are in orbit, otherwise the Milky Way would collapse under its own gravity. One orbit of the Sun around the center of the Milky Way, which we can call one galactic year, takes about 220 million years. Given its age of 4.5 billion years, it has made 20 or so revolutions ...
... the Sun. In fact all the stars are in orbit, otherwise the Milky Way would collapse under its own gravity. One orbit of the Sun around the center of the Milky Way, which we can call one galactic year, takes about 220 million years. Given its age of 4.5 billion years, it has made 20 or so revolutions ...
ALFALFA H-alpha: The Star-Formation-Rate Density
... One class in particular – John Salzer’s Introduction to Astronomical Techniques – converted me to an astronomy major. For this and two years’ focus and advising, I would like to thank John first and foremost. He has taught me IRAF, taken me to Kitt Peak, and spent countless hours explaining the back ...
... One class in particular – John Salzer’s Introduction to Astronomical Techniques – converted me to an astronomy major. For this and two years’ focus and advising, I would like to thank John first and foremost. He has taught me IRAF, taken me to Kitt Peak, and spent countless hours explaining the back ...
The local spiral structure of the Milky Way
... main arc of the Local Arm. Instead, these sources, as well as G059.78+00.06 and ON 1, branch off and curve inward in the Milky Way. As the dotted line in Fig. 2 suggests, these sources trace what appears to be a high-inclination spur bridging the Local Arm to the Sagittarius Arm near l ≈ 50°. Additi ...
... main arc of the Local Arm. Instead, these sources, as well as G059.78+00.06 and ON 1, branch off and curve inward in the Milky Way. As the dotted line in Fig. 2 suggests, these sources trace what appears to be a high-inclination spur bridging the Local Arm to the Sagittarius Arm near l ≈ 50°. Additi ...
Star Clusters in Mergers
... their distance), hence only slightly fainter. Statistics not different physics. ...
... their distance), hence only slightly fainter. Statistics not different physics. ...
PPT presentation
... an excellent standard candle. Model simulations indicated a central star mass distribution highly peaked at ~0.6 Msun, similar to that of nearby white dwarfs. ...
... an excellent standard candle. Model simulations indicated a central star mass distribution highly peaked at ~0.6 Msun, similar to that of nearby white dwarfs. ...
GALEX and Star Formation
... revealed in extreme low-density environments, where it is elusive at other wavelengths. UV measurements of millions of more distant galaxies probe their evolution and the Universe’s star-formation history (SFH) since redshift ∼2. In this review, we first recall the basic characteristics of GALEX dat ...
... revealed in extreme low-density environments, where it is elusive at other wavelengths. UV measurements of millions of more distant galaxies probe their evolution and the Universe’s star-formation history (SFH) since redshift ∼2. In this review, we first recall the basic characteristics of GALEX dat ...
Galaxy
A galaxy is a gravitationally bound system of stars, stellar remnants, interstellar gas and dust, and dark matter. The word galaxy is derived from the Greek galaxias (γαλαξίας), literally ""milky"", a reference to the Milky Way. Galaxies range in size from dwarfs with just a few thousand (103) stars to giants with one hundred trillion (1014) stars, each orbiting their galaxy's own center of mass. Galaxies are categorized according to their visual morphology, including elliptical, spiral, and irregular. Many galaxies are thought to have black holes at their active centers. The Milky Way's central black hole, known as Sagittarius A*, has a mass four million times greater than our own Sun. As of July 2015, EGSY8p7 is the oldest and most distant galaxy with a light travel distance of 13.2 billion light-years from Earth, and observed as it existed 570 million years after the Big Bang. Previously, as of May 2015, EGS-zs8-1 was the most distant known galaxy, estimated to have a light travel distance of 13.1 billion light-years away and to have 15% of the mass of the Milky Way.Approximately 170 billion (1.7 × 1011) to 200 billion (2.0 × 1011) galaxies exist in the observable universe. Most of the galaxies are 1,000 to 100,000 parsecs in diameter and usually separated by distances on the order of millions of parsecs (or megaparsecs). The space between galaxies is filled with a tenuous gas with an average density less than one atom per cubic meter. The majority of galaxies are gravitationally organized into associations known as galaxy groups, clusters, and superclusters. At the largest scale, these associations are generally arranged into sheets and filaments that are surrounded by immense voids.