Ionized gas discs in elliptical and S0 galaxies at z < 1
... into the cluster, clearly indicating that the transformation of spirals to S0s is accelerated by cluster environment. All of the above-mentioned studies however have been done at low redshift. In this paper, we present, for the first time, observational evidence for extended emission discs in ETGs a ...
... into the cluster, clearly indicating that the transformation of spirals to S0s is accelerated by cluster environment. All of the above-mentioned studies however have been done at low redshift. In this paper, we present, for the first time, observational evidence for extended emission discs in ETGs a ...
Stellar Masses
... The drastic changes seen in the mass–luminosity relation with mass are primarily due to the different opacity sources at work. At the high interior temperatures that characterize high-mass stars, all of the atoms are fully ionized and scattering of x-rays from free electrons dominates the opacity, w ...
... The drastic changes seen in the mass–luminosity relation with mass are primarily due to the different opacity sources at work. At the high interior temperatures that characterize high-mass stars, all of the atoms are fully ionized and scattering of x-rays from free electrons dominates the opacity, w ...
Stellar Evolution : The Life and Death of Our Luminous Neighbors
... e. they are all so far away that the light hasn't reached us yet. 2. The nuclear reactions in a star's core remain under control so long as a. b. c. d. ...
... e. they are all so far away that the light hasn't reached us yet. 2. The nuclear reactions in a star's core remain under control so long as a. b. c. d. ...
Star Formation and Young Clusters in Cygnus
... Figure 1 shows the extinction from the main molecular cloud complexes in Cygnus based on the star count data by Dobashi et al. (2005). The figure shows the Galactic plane between longitudes 67◦ and 100◦ . The Great Cygnus Rift is most prominent to the right, and the 10 degree large Cygnus X region p ...
... Figure 1 shows the extinction from the main molecular cloud complexes in Cygnus based on the star count data by Dobashi et al. (2005). The figure shows the Galactic plane between longitudes 67◦ and 100◦ . The Great Cygnus Rift is most prominent to the right, and the 10 degree large Cygnus X region p ...
A large-scale CO survey of the Rosette Molecular Cloud: assessing
... lines. The image also shows that many of the clumps and clouds are limb brightening on their edge facing the O stars. By consideration of the full data cube, we identify three distinct spatiovelocity structures: (1) relatively compact regions with broad line wings, identified as compact or well-coll ...
... lines. The image also shows that many of the clumps and clouds are limb brightening on their edge facing the O stars. By consideration of the full data cube, we identify three distinct spatiovelocity structures: (1) relatively compact regions with broad line wings, identified as compact or well-coll ...
ppt - SLAC
... Wolf-Rayet stars are hot (25-50,000+ degrees K), massive stars (20+ solar mass) with a high rate of mass loss. (This is WR124, at 19h11 +16 ) A few other spectral types don't fit the sequence but instead parallel it. Type W or Wolf-Rayet stars are as hot and blue as the hottest O stars but show stro ...
... Wolf-Rayet stars are hot (25-50,000+ degrees K), massive stars (20+ solar mass) with a high rate of mass loss. (This is WR124, at 19h11 +16 ) A few other spectral types don't fit the sequence but instead parallel it. Type W or Wolf-Rayet stars are as hot and blue as the hottest O stars but show stro ...
A Comparison of CCD Images Taken with Different Cameras Abstract
... 150,000 K at its surface and is known as a "white dwarf". After billions of years, the white dwarf will eventually cool and stop giving off light. The expanding gas cloud will dissipate in a few tens of thousands of years. ...
... 150,000 K at its surface and is known as a "white dwarf". After billions of years, the white dwarf will eventually cool and stop giving off light. The expanding gas cloud will dissipate in a few tens of thousands of years. ...
GRB 021004: A Possible Shell Nebula around a Wolf
... black hole surrounded by an accretion disk wind [14]. While it is now generally accepted that some long-duration GRBs are associated with the deaths of massive stars, considerable uncertainty remains as to what the precise nature of the progenitor star is. Theories of stellar evolution suggest that ...
... black hole surrounded by an accretion disk wind [14]. While it is now generally accepted that some long-duration GRBs are associated with the deaths of massive stars, considerable uncertainty remains as to what the precise nature of the progenitor star is. Theories of stellar evolution suggest that ...
Table of Contents - Imiloa Astronomy Center
... was, is purported to have asked Job if he (Job) was able to “loose the bands of Orion” (Job ...
... was, is purported to have asked Job if he (Job) was able to “loose the bands of Orion” (Job ...
A prevalence of dynamo-generated magnetic fields in the
... for suppression. However, the hint of a decline in the occurrence of dipole-suppressed stars above 2M" seen in Fig. 3 suggests there may be a mass above which dynamo-generated magnetic fields are less likely to cause oscillation mode suppression in intermediate-mass stars. The high occurrence rate o ...
... for suppression. However, the hint of a decline in the occurrence of dipole-suppressed stars above 2M" seen in Fig. 3 suggests there may be a mass above which dynamo-generated magnetic fields are less likely to cause oscillation mode suppression in intermediate-mass stars. The high occurrence rate o ...
Nuclear Activity in UZC Compact Groups of Galaxies M.A. Martinez
... have high galaxy density and low velocity dispersion, conditions that maximize the number of gravitational encounters. Compact Groups of Galaxies (CGs) satisfy both conditions and, moreover, being located in low density surrounding environments, guarantee that environment influence may arise only fr ...
... have high galaxy density and low velocity dispersion, conditions that maximize the number of gravitational encounters. Compact Groups of Galaxies (CGs) satisfy both conditions and, moreover, being located in low density surrounding environments, guarantee that environment influence may arise only fr ...
Global star formation in the Milky Way from the VIALACTEA
... Key-questions in Galactic astronomy • What are the agents determining the star formation rate and history in a normal Galaxy like the Milky Way ? • What are the ingredients determining star formation laws as a function of ISM properties across a full range of galactocentric radii, metallicity and ...
... Key-questions in Galactic astronomy • What are the agents determining the star formation rate and history in a normal Galaxy like the Milky Way ? • What are the ingredients determining star formation laws as a function of ISM properties across a full range of galactocentric radii, metallicity and ...
PSF - ESO
... First you must FIND the stellar-appearing objects in the frame. Each program has its own method - sometimes several methods – of performing this, but the basic idea is to produce an initial list of approximate centroid positions for all stars that can be distinguished in the two dimensional data arr ...
... First you must FIND the stellar-appearing objects in the frame. Each program has its own method - sometimes several methods – of performing this, but the basic idea is to produce an initial list of approximate centroid positions for all stars that can be distinguished in the two dimensional data arr ...
Stellar Physics
... black of night. You see a single light which may be a motorcycle. How do you know how far way it is? (Is it a motorcycle or something else?) Practical demonstration: various small light sources of varying brightnesses could be placed in a totally darkened room or corridor. Four would be a suitable n ...
... black of night. You see a single light which may be a motorcycle. How do you know how far way it is? (Is it a motorcycle or something else?) Practical demonstration: various small light sources of varying brightnesses could be placed in a totally darkened room or corridor. Four would be a suitable n ...
Studying the Universe Studying the Universe
... are called reflecting telescopes. Light enters the telescope and is reflected from a large, curved mirror to a focal point above the mirror. A focal point is the point on the axis of a mirror or lens through which parallel light rays are focused. As shown in Figure 8, reflecting telescopes use a sec ...
... are called reflecting telescopes. Light enters the telescope and is reflected from a large, curved mirror to a focal point above the mirror. A focal point is the point on the axis of a mirror or lens through which parallel light rays are focused. As shown in Figure 8, reflecting telescopes use a sec ...
Stars A globular cluster is a tightly grouped swarm of stars held
... The distance from the sun to Proxima Centauri is more than 25 trillion miles (40 trillion kilometers). This distance is so great that light takes 4.2 years to travel between the two stars. Scientists say that Proxima Centauri is 4.2 light-years from the sun. One light-year, the distance that light t ...
... The distance from the sun to Proxima Centauri is more than 25 trillion miles (40 trillion kilometers). This distance is so great that light takes 4.2 years to travel between the two stars. Scientists say that Proxima Centauri is 4.2 light-years from the sun. One light-year, the distance that light t ...
outer-disk populations in ngc 7793: evidence for stellar
... We analyzed the radial surface brightness profile of the spiral galaxy NGC 7793 using HST/ACS images from the GHOSTS survey and a new HST/WFC3 image across the disk break. We used the photometry of resolved stars to select distinct populations covering a wide range of stellar ages. We found breaks i ...
... We analyzed the radial surface brightness profile of the spiral galaxy NGC 7793 using HST/ACS images from the GHOSTS survey and a new HST/WFC3 image across the disk break. We used the photometry of resolved stars to select distinct populations covering a wide range of stellar ages. We found breaks i ...
stars - acpsd
... luminosity and surface temperature place it in sequence on a Hertzsprung- Russell diagram. A fundamental property of all main sequence stars is thermal equilibrium. Thermal equilibrium is the liberation of energy from the interior of the star balanced by the energy released at the surface of the sta ...
... luminosity and surface temperature place it in sequence on a Hertzsprung- Russell diagram. A fundamental property of all main sequence stars is thermal equilibrium. Thermal equilibrium is the liberation of energy from the interior of the star balanced by the energy released at the surface of the sta ...
Ch 20 Stellar Evolution
... Its path across the H-R diagram is essentially a straight line —it stays at just about the same luminosity as it cools off. Eventually the star dies in a violent explosion called a supernova. ...
... Its path across the H-R diagram is essentially a straight line —it stays at just about the same luminosity as it cools off. Eventually the star dies in a violent explosion called a supernova. ...
CHAPTER 7—ATOMS AND STARLIGHT
... ____ 35. Isotopes of the same element have the same number of protons. ____ 36. Hydrogen alpha is the longest wavelength Balmer line. ____ 37. An absorption spectrum is also called a bright line spectrum. ____ 38. Stars of spectra type K have strong Balmer lines. ____ 39. The Doppler effect is sensi ...
... ____ 35. Isotopes of the same element have the same number of protons. ____ 36. Hydrogen alpha is the longest wavelength Balmer line. ____ 37. An absorption spectrum is also called a bright line spectrum. ____ 38. Stars of spectra type K have strong Balmer lines. ____ 39. The Doppler effect is sensi ...
Arcturus - bYTEBoss
... Exactly whom Boötes is supposed to represent is not clear. According to one version, he was a ploughman who drove the oxen in the constellation Ursa Major using his two dogs Chara and Asterion (from the constellation Canes Venatici). The oxen were tied to the polar axis and so the action of Boötes k ...
... Exactly whom Boötes is supposed to represent is not clear. According to one version, he was a ploughman who drove the oxen in the constellation Ursa Major using his two dogs Chara and Asterion (from the constellation Canes Venatici). The oxen were tied to the polar axis and so the action of Boötes k ...
December - Rose City Astronomers
... and open cluster combo is a remarkable stroke of cosmic serendipity in an area nearly devoid of other major deep-sky objects. The refractor at 44x shows the 12' diameter star cluster as six stars (9th to 11thmagnitude) embedded in a background haze of a half dozen more fainter suns. The Triangulum o ...
... and open cluster combo is a remarkable stroke of cosmic serendipity in an area nearly devoid of other major deep-sky objects. The refractor at 44x shows the 12' diameter star cluster as six stars (9th to 11thmagnitude) embedded in a background haze of a half dozen more fainter suns. The Triangulum o ...
Project 5: Globular cluster
... by gravity. Globular clusters orbit around the Milky Way galaxy core like satellites. The number of stars in a globular cluster varies from a few thousand up to a million stars for the more massive ones. There are ~150 known globular clusters that orbit our own Milky Way galaxy cor ...
... by gravity. Globular clusters orbit around the Milky Way galaxy core like satellites. The number of stars in a globular cluster varies from a few thousand up to a million stars for the more massive ones. There are ~150 known globular clusters that orbit our own Milky Way galaxy cor ...
H II region
An H II region is a large, low-density cloud of partially ionized gas in which star formation has recently taken place. The short-lived blue stars forged in these regions emit copious amounts of ultraviolet light that ionize the surrounding gas. H II regions—sometimes several hundred light-years across—are often associated with giant molecular clouds. The first known H II region was the Orion Nebula, which was discovered in 1610 by Nicolas-Claude Fabri de Peiresc.H II regions are named for the large amount of ionised atomic hydrogen they contain, referred to as H II, pronounced H-two by astronomers (an H I region being neutral atomic hydrogen, and H2 being molecular hydrogen). Such regions have extremely diverse shapes, because the distribution of the stars and gas inside them is irregular. They often appear clumpy and filamentary, sometimes showing bizarre shapes such as the Horsehead Nebula. H II regions may give birth to thousands of stars over a period of several million years. In the end, supernova explosions and strong stellar winds from the most massive stars in the resulting star cluster will disperse the gases of the H II region, leaving behind a cluster of birthed stars such as the Pleiades.H II regions can be seen to considerable distances in the universe, and the study of extragalactic H II regions is important in determining the distance and chemical composition of other galaxies. Spiral and irregular galaxies contain many H II regions, while elliptical galaxies are almost devoid of them. In the spiral galaxies, including the Milky Way, H II regions are concentrated in the spiral arms, while in the irregular galaxies they are distributed chaotically. Some galaxies contain huge H II regions, which may contain tens of thousands of stars. Examples include the 30 Doradus region in the Large Magellanic Cloud and NGC 604 in the Triangulum Galaxy.