instructor notes stellar evolution, star clusters
... Upsilon components apply when the Sun’s motion dominates group random velocities; tau components apply when group motions dominate. Both techniques have been applied to B stars and RR Lyrae variables, which are too distant for direct measurement of distance by standard techniques. Both classes of ob ...
... Upsilon components apply when the Sun’s motion dominates group random velocities; tau components apply when group motions dominate. Both techniques have been applied to B stars and RR Lyrae variables, which are too distant for direct measurement of distance by standard techniques. Both classes of ob ...
instructor notes stellar evolution, star clusters
... Upsilon components apply when the Sun’s motion dominates group random velocities; tau components apply when group motions dominate. Both techniques have been applied to B stars and RR Lyrae variables, which are too distant for direct measurement of distance by standard techniques. Both classes of ob ...
... Upsilon components apply when the Sun’s motion dominates group random velocities; tau components apply when group motions dominate. Both techniques have been applied to B stars and RR Lyrae variables, which are too distant for direct measurement of distance by standard techniques. Both classes of ob ...
Magnitude of Stars - What`s Out Tonight?
... The stars in the sky vary in brightness for two reasons. The first is because they are all at different distances. The farther away a star is, the fainter it will appear. The second reason has to do with their sizes. Larger stars have more surface area so they give off more light and appear brighter ...
... The stars in the sky vary in brightness for two reasons. The first is because they are all at different distances. The farther away a star is, the fainter it will appear. The second reason has to do with their sizes. Larger stars have more surface area so they give off more light and appear brighter ...
ppt
... – We demonstrate the importance of sampling the full probability distribution of parameters in the stellar population synthesis modeling of galaxy spectra (i.e. MCMC in general give different results from chisq minimization). – Degeneracies between intrinsic dust extinction and other parameters esti ...
... – We demonstrate the importance of sampling the full probability distribution of parameters in the stellar population synthesis modeling of galaxy spectra (i.e. MCMC in general give different results from chisq minimization). – Degeneracies between intrinsic dust extinction and other parameters esti ...
M81/M82/NGC3077
... (CBR value: 48 km/sec) M82 — 202 km/sec (3.9 ± 0.3 Mpc) (CBR value: 296 km/sec) M81 is closer and approaching, while M82 is farther away and receding; ...
... (CBR value: 48 km/sec) M82 — 202 km/sec (3.9 ± 0.3 Mpc) (CBR value: 296 km/sec) M81 is closer and approaching, while M82 is farther away and receding; ...
Lecture 12: Galaxy Evolution
... • E.g., Dust (either in our galaxy, the target galaxy or some inbetween IGM). ...
... • E.g., Dust (either in our galaxy, the target galaxy or some inbetween IGM). ...
Document
... of both iron and alpha elements. A model is chosen that provides an excellent fit to the metallicity distribution of stars in the Geneva-Copenhagen survey (GCS) of the solar neighbourhood, and an acceptable fit to the local Hess diagram. The model provides a good fit to the distribution of GCS stars ...
... of both iron and alpha elements. A model is chosen that provides an excellent fit to the metallicity distribution of stars in the Geneva-Copenhagen survey (GCS) of the solar neighbourhood, and an acceptable fit to the local Hess diagram. The model provides a good fit to the distribution of GCS stars ...
Gravitational Lensing, SZ Effects, and Large
... However, around real clusters, the probability of high noise peaks can be higher than average ...
... However, around real clusters, the probability of high noise peaks can be higher than average ...
observational requirements, feasability, expectations
... Activity time scale with COROT (visible light) : spots lifetime combined with rotation period (solar case not so simple; instrumental low frequency noise) No real law, even empirical, to estimate the activity time scale exploratory approach based on many stars and comparison to their rotation peri ...
... Activity time scale with COROT (visible light) : spots lifetime combined with rotation period (solar case not so simple; instrumental low frequency noise) No real law, even empirical, to estimate the activity time scale exploratory approach based on many stars and comparison to their rotation peri ...
Document
... abundances for the Leo II dSph: errors on individual stars are large but the mean trends are reliable. Evan Kirby has been developing a technique for determining alpha and Fe for DEIMOS-Keck spectra in a large number of dSph galaxies. This technique is growing in sophistication and will soon measure ...
... abundances for the Leo II dSph: errors on individual stars are large but the mean trends are reliable. Evan Kirby has been developing a technique for determining alpha and Fe for DEIMOS-Keck spectra in a large number of dSph galaxies. This technique is growing in sophistication and will soon measure ...
WFIRSTSurveyScience
... which will provide important constraints on the material properties of KBOs and their collisional evolution. In addition, WFIRST will enable us to make, for the first time, detailed comparisons between the size distributions of KBOs in different dynamical classes, shedding light onto the origin of t ...
... which will provide important constraints on the material properties of KBOs and their collisional evolution. In addition, WFIRST will enable us to make, for the first time, detailed comparisons between the size distributions of KBOs in different dynamical classes, shedding light onto the origin of t ...
(Science 2012) Gal-Yam
... or as traces of circumstellar material (CSM) interaction]; hence, the ejecta mass directly constrains the mass of the exploding helium core, which is likely dominated by oxygen and heavier elements. Scaling relations based on the work of Arnett (17), as well as comparison of the data to custom light ...
... or as traces of circumstellar material (CSM) interaction]; hence, the ejecta mass directly constrains the mass of the exploding helium core, which is likely dominated by oxygen and heavier elements. Scaling relations based on the work of Arnett (17), as well as comparison of the data to custom light ...
1 Introduction for non-astronomers 1.1 Our expanding universe
... dark matter seems to have the same gravitational attraction as baryonic matter, it does not emit light, at any wavelength. This makes it very difficult to detect directly, and it is only by the indirect gravitational influence of dark matter that we know it is there at all. During this slow overall ...
... dark matter seems to have the same gravitational attraction as baryonic matter, it does not emit light, at any wavelength. This makes it very difficult to detect directly, and it is only by the indirect gravitational influence of dark matter that we know it is there at all. During this slow overall ...
stars and beyond - Math/Science Nucleus
... A galaxy is a large scale aggregate of stars, plus some gas, dust, and possibly solar systems, which are held together by gravity. A globular cluster is a roughly spherical group of hundreds of thousands to millions stars, also held together by gravity. Globular clusters seem to be made of very old ...
... A galaxy is a large scale aggregate of stars, plus some gas, dust, and possibly solar systems, which are held together by gravity. A globular cluster is a roughly spherical group of hundreds of thousands to millions stars, also held together by gravity. Globular clusters seem to be made of very old ...
determination of the distance to the galactic centre nigel clayton
... Abstract: This paper summarises an investigation into the wide ranging methods employed to determine the distance to the Galactic centre, Ro. Remote methods commonly use luminosity reference objects such as RR Lyraes and red clump stars. Ruler methods involve annual parallax or line-of-sight velocit ...
... Abstract: This paper summarises an investigation into the wide ranging methods employed to determine the distance to the Galactic centre, Ro. Remote methods commonly use luminosity reference objects such as RR Lyraes and red clump stars. Ruler methods involve annual parallax or line-of-sight velocit ...
The 2008 RBSE Journal - National Optical Astronomy Observatory
... and usually end up being bigger than the originating galaxy. The smallest known are only a few tens of parsecs across, while the largest are known to be up to several megaparsecs. The average radio galaxy is usually typically hundreds of kiloparsecs across. This is about twice the size of the Milky ...
... and usually end up being bigger than the originating galaxy. The smallest known are only a few tens of parsecs across, while the largest are known to be up to several megaparsecs. The average radio galaxy is usually typically hundreds of kiloparsecs across. This is about twice the size of the Milky ...
Physical properties of Hα selected star forming galaxies at z ~ 0.84
... where Li is the central luminosity in the bin i and V (z)j is the maximum volume in which object j can be detected. Before computing the Hα luminosity function we have to consider two important effects affecting our sample: extinction and completeness. The amount of extinction for each galaxy was es ...
... where Li is the central luminosity in the bin i and V (z)j is the maximum volume in which object j can be detected. Before computing the Hα luminosity function we have to consider two important effects affecting our sample: extinction and completeness. The amount of extinction for each galaxy was es ...
A6 - Vicphysics
... are visible) and the Moon. With the Moon, concentrate on the terminator, the line between day and night. Some of the brighter variable stars may also be worth observing. The Astronomical Society of South Australia’s Variable Star Group has a useful introductory page on observing at http://www.assa.o ...
... are visible) and the Moon. With the Moon, concentrate on the terminator, the line between day and night. Some of the brighter variable stars may also be worth observing. The Astronomical Society of South Australia’s Variable Star Group has a useful introductory page on observing at http://www.assa.o ...
Chapter 26: Stars, Galaxies, and the Universe Stars
... distant stars. Then, they wait 6 months; during this time, Earth moves from one side of its orbit around the Sun to the other side. When they look at the star again, parallax will cause the star to appear in a different position relative to more distant stars. From the size of this shift, they can c ...
... distant stars. Then, they wait 6 months; during this time, Earth moves from one side of its orbit around the Sun to the other side. When they look at the star again, parallax will cause the star to appear in a different position relative to more distant stars. From the size of this shift, they can c ...
Galaxies
... e. the stars in the spiral arms emit most of their energy at radio wavelengths. If the spiral density wave were the only thing producing spiral arms, it would be expected that a. all spiral arms would be dust free. b. all galaxies would have only two smooth spiral arms. c. the Milky Way would be mor ...
... e. the stars in the spiral arms emit most of their energy at radio wavelengths. If the spiral density wave were the only thing producing spiral arms, it would be expected that a. all spiral arms would be dust free. b. all galaxies would have only two smooth spiral arms. c. the Milky Way would be mor ...
SSS in young stellar populations: progenitors of the
... • SSS in these systems could be TNR on white dwarf once it accretes critical mass from Be disk • WDs could experience accretion and outburst cycles like in novae, and possible gain in mass with time • WDs initially massive, so require less mass to reach MCh • Mass accretion can be more efficient if ...
... • SSS in these systems could be TNR on white dwarf once it accretes critical mass from Be disk • WDs could experience accretion and outburst cycles like in novae, and possible gain in mass with time • WDs initially massive, so require less mass to reach MCh • Mass accretion can be more efficient if ...
Summary of IAU GA SpS5-I. Obscured and distant clusters
... The past two decades have seen a three-fold increase in the number of known Galactic WR stars. As the majority of these newly discovered objects are visually obscured, it is essential to develop our capability to analyze these rare and valuable stars at IR wavelengths. Furthermore, a comprehensive k ...
... The past two decades have seen a three-fold increase in the number of known Galactic WR stars. As the majority of these newly discovered objects are visually obscured, it is essential to develop our capability to analyze these rare and valuable stars at IR wavelengths. Furthermore, a comprehensive k ...
Young Galaxies Grow - Astronomical Society of the Pacific
... of matter. Their brightest component is a flat, dense disk, where most of their stars are formed along spiral arms. Our Milky Way is a spiral galaxy. Such disk galaxies mostly assembled in earlier epochs, but they continue to form stars today from remaining gas within the spiral arms. They are also ...
... of matter. Their brightest component is a flat, dense disk, where most of their stars are formed along spiral arms. Our Milky Way is a spiral galaxy. Such disk galaxies mostly assembled in earlier epochs, but they continue to form stars today from remaining gas within the spiral arms. They are also ...
19. Our Galaxy 19.1 The Milky Way Revealed Our goals for learning
... • What is the significance of a rotation curve that is flat at large distances from the galactic center? • The Milky Way’s flat rotation curve implies that the matter associated with our galaxy extends to large distances from the center. A rotation curve is a plot of the orbital speed of stars or ga ...
... • What is the significance of a rotation curve that is flat at large distances from the galactic center? • The Milky Way’s flat rotation curve implies that the matter associated with our galaxy extends to large distances from the center. A rotation curve is a plot of the orbital speed of stars or ga ...
ACTIVE GALAXIES
... (QSR) • large: classical double radio galaxy (FR II type) • Low MBH. M_dot: • very small: BL Lac object • small: broad line radio galaxy (FR I type) • large: narrow line radio galaxy ...
... (QSR) • large: classical double radio galaxy (FR II type) • Low MBH. M_dot: • very small: BL Lac object • small: broad line radio galaxy (FR I type) • large: narrow line radio galaxy ...
Cosmic distance ladder
The cosmic distance ladder (also known as the extragalactic distance scale) is the succession of methods by which astronomers determine the distances to celestial objects. A real direct distance measurement of an astronomical object is possible only for those objects that are ""close enough"" (within about a thousand parsecs) to Earth. The techniques for determining distances to more distant objects are all based on various measured correlations between methods that work at close distances and methods that work at larger distances. Several methods rely on a standard candle, which is an astronomical object that has a known luminosity.The ladder analogy arises because no one technique can measure distances at all ranges encountered in astronomy. Instead, one method can be used to measure nearby distances, a second can be used to measure nearby to intermediate distances, and so on. Each rung of the ladder provides information that can be used to determine the distances at the next higher rung.