The SMC as a probe of dust in the early Universe
... by carbon stars, and have left some critical holes. Stars in clusters are particularly important, because they have known metallicities and ages (and therefore masses on the AGB). Supergiants contribute ∼10% of the dust ejected into the ISM, but only four have been observed in the SMC. We will expan ...
... by carbon stars, and have left some critical holes. Stars in clusters are particularly important, because they have known metallicities and ages (and therefore masses on the AGB). Supergiants contribute ∼10% of the dust ejected into the ISM, but only four have been observed in the SMC. We will expan ...
Chandra Characterization of X-ray Emission in the Young F
... 3.1 Luminosity Results. Using Chandra, we have found an HD 113766 system with Chandra count rate and luminosity very close to the published RASS values. The observed x-ray emission can be accounted for by two stellar coronal sources located at the positions of HD 113766A and HD 113766B. HD 113766A i ...
... 3.1 Luminosity Results. Using Chandra, we have found an HD 113766 system with Chandra count rate and luminosity very close to the published RASS values. The observed x-ray emission can be accounted for by two stellar coronal sources located at the positions of HD 113766A and HD 113766B. HD 113766A i ...
Was a cloud-cloud collision the trigger of the recent star formation in
... estimated an average age of 105 yr for these sources, which could possibly point to a triggering event. Older sources are also found in the field, but they appear more dispersed, without an obvious connection to the current protostars, and are no longer embedded or surrounded by any cold dust seen a ...
... estimated an average age of 105 yr for these sources, which could possibly point to a triggering event. Older sources are also found in the field, but they appear more dispersed, without an obvious connection to the current protostars, and are no longer embedded or surrounded by any cold dust seen a ...
The Oort Cloud
... of the ancient protoplanetary disk, they did not use up all of the material in their vicinity. A large amount of icy and rocky debris was left orbiting the sun along the planets' path and in between them. On occasion, when one of these objects, known as "planetesimals" would stray too close to one o ...
... of the ancient protoplanetary disk, they did not use up all of the material in their vicinity. A large amount of icy and rocky debris was left orbiting the sun along the planets' path and in between them. On occasion, when one of these objects, known as "planetesimals" would stray too close to one o ...
... Theory and observations point to a variety of processes that redistribute energy in disks. In Section 2, we review evidence that bars and ovals rearrange disk gas into outer rings, inner rings, and central mass concentrations. The resulting star formation produces a central stellar subsystem that ha ...
Star Formation in the Milky Way and Nearby Galaxies Further
... et al. 2008; Heiderman et al. 2010; Lada, Lombardi & Alves 2010), a volume-density criterion (typically n > 104 cm−3 ) (e.g., Lada 1992), and detection of a line from certain molecules, such as HCN. The surface- and volume-density criteria roughly agree in nearby clouds (Lada et al. 2012), but they ...
... et al. 2008; Heiderman et al. 2010; Lada, Lombardi & Alves 2010), a volume-density criterion (typically n > 104 cm−3 ) (e.g., Lada 1992), and detection of a line from certain molecules, such as HCN. The surface- and volume-density criteria roughly agree in nearby clouds (Lada et al. 2012), but they ...
Stars and Planets Credits and Acknowledgements
... The Stars and Planets sequence begins with a hands-on version of the classic scale model solar system activity that uses a scale factor of 1:10 billion for both size and distance, and then expands the idea to include stars and planets beyond the solar system using the same 1: 10 billion scale. Mathe ...
... The Stars and Planets sequence begins with a hands-on version of the classic scale model solar system activity that uses a scale factor of 1:10 billion for both size and distance, and then expands the idea to include stars and planets beyond the solar system using the same 1: 10 billion scale. Mathe ...
observations of white dwarfs in the solar neighborhood
... within 20 pc of the Sun. Holberg, Oswalt, & Sion (2002) have compiled a list of 109 white dwarfs that lie within 20 pc of the Sun, and they found that the sample is complete to 13 pc and 65% complete to 20 pc. Therefore, 50 white dwarfs remain undiscovered within 20 pc of the Sun. In combining accu ...
... within 20 pc of the Sun. Holberg, Oswalt, & Sion (2002) have compiled a list of 109 white dwarfs that lie within 20 pc of the Sun, and they found that the sample is complete to 13 pc and 65% complete to 20 pc. Therefore, 50 white dwarfs remain undiscovered within 20 pc of the Sun. In combining accu ...
Physics of the Interstellar Medium
... called the interstellar medium (ISM). The average particle density of the ISM is 1 cm−3 which represents a density lower than can be created on Earth. The ISM therefore represents a fascinating laboratory to study the physics of highly attenuated gases, chemical processes and atomic, molecular and s ...
... called the interstellar medium (ISM). The average particle density of the ISM is 1 cm−3 which represents a density lower than can be created on Earth. The ISM therefore represents a fascinating laboratory to study the physics of highly attenuated gases, chemical processes and atomic, molecular and s ...
21_Testbank
... ordered stellar orbits, compresses the gas and causes it to rapidly form stars, eventually producing a gas-free, elliptical galaxy. 2) Briefly explain why starburst galaxies appear fairly ordinary when they are observed in visible light but extraordinary when they are observed in infrared light. Ans ...
... ordered stellar orbits, compresses the gas and causes it to rapidly form stars, eventually producing a gas-free, elliptical galaxy. 2) Briefly explain why starburst galaxies appear fairly ordinary when they are observed in visible light but extraordinary when they are observed in infrared light. Ans ...
Science Case for the Chinese Participation of TMT
... reveal that the Universe is dominated by dark matter and dark energy. The nature of these two dark components is the most fundamental question in (astro-)physics today. The discovery of more than 400 extrasolar planet systems indicates that our solar system may be the exception rather than the norm; ...
... reveal that the Universe is dominated by dark matter and dark energy. The nature of these two dark components is the most fundamental question in (astro-)physics today. The discovery of more than 400 extrasolar planet systems indicates that our solar system may be the exception rather than the norm; ...
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... San Diego Supercomputing Center for their invaluable assistance, which often took place at extremely non-standard work hours. I would also like to thank Cheryl Matson, Dayna Gallegos, and Wendy Wimmer for their extremely efficient administrative support. I would like to thank Richard Cyburt for pro ...
... San Diego Supercomputing Center for their invaluable assistance, which often took place at extremely non-standard work hours. I would also like to thank Cheryl Matson, Dayna Gallegos, and Wendy Wimmer for their extremely efficient administrative support. I would like to thank Richard Cyburt for pro ...
Open clusters and associations in the Gaia era
... an issue if the survey does not extend beyond the cluster tidal radius, especially if there is mass segregation as the incompleteness level will then depend on mass. Moreover, objects might be missed around bright stars due to contrast issue, in crowded regions or in area with high extinction. As fo ...
... an issue if the survey does not extend beyond the cluster tidal radius, especially if there is mass segregation as the incompleteness level will then depend on mass. Moreover, objects might be missed around bright stars due to contrast issue, in crowded regions or in area with high extinction. As fo ...
The environment of high-redshift AGN OLIMPIA JUDIT FOGASY
... According to the currently accepted cosmological model, the Λ Cold Dark Matter model (ΛCDM), structure formation started from primordial density fluctuations followed by gravitational collapse of dark matter, leading to the formation of dark matter haloes. As the virial equilibrium is reached in the ...
... According to the currently accepted cosmological model, the Λ Cold Dark Matter model (ΛCDM), structure formation started from primordial density fluctuations followed by gravitational collapse of dark matter, leading to the formation of dark matter haloes. As the virial equilibrium is reached in the ...
Evolution of stars
... e. they are all so far away that the light hasn't reached us yet. The nuclear reactions in a star's core remain under control so long as a. luminosity depends on mass. b. pressure depends on temperature. c. density depends on mass. d. weight depends on temperature. e. temperature depends on mass. In ...
... e. they are all so far away that the light hasn't reached us yet. The nuclear reactions in a star's core remain under control so long as a. luminosity depends on mass. b. pressure depends on temperature. c. density depends on mass. d. weight depends on temperature. e. temperature depends on mass. In ...
Exploring Neutral Hydrogen and Galaxy Evolution with the SKA
... baryons existed almost entirely in gaseous form, and it is through the infall of this material onto the filamentary structures of the cosmic web, its accretion into the deepest potential wells, and ultimate collapse into dense molecular clouds, that galaxies were able to start forming and producing ...
... baryons existed almost entirely in gaseous form, and it is through the infall of this material onto the filamentary structures of the cosmic web, its accretion into the deepest potential wells, and ultimate collapse into dense molecular clouds, that galaxies were able to start forming and producing ...
Reassessing the formation of the inner Oort cloud
... orbits with semi-major axes ∼ 200 AU and included an approximate model of the tidal field of the gas and passing stars from the cluster. The cluster had a maximum stellar number density of 100 pc−3 and the maximum mass density of the core of the molecular cloud gas was 5000 M⊙ pc−3 . Their simulatio ...
... orbits with semi-major axes ∼ 200 AU and included an approximate model of the tidal field of the gas and passing stars from the cluster. The cluster had a maximum stellar number density of 100 pc−3 and the maximum mass density of the core of the molecular cloud gas was 5000 M⊙ pc−3 . Their simulatio ...
Orion the Hunter
... Hunter. Its brightest stars form one of the best known celestial shapes, which is visible even from cities. The plane of the Milky Way clips the northeast corner of the constellation and manifests itself as a featureless, hazy band through the neighboring constellations of Gemini and Monoceros. Or ...
... Hunter. Its brightest stars form one of the best known celestial shapes, which is visible even from cities. The plane of the Milky Way clips the northeast corner of the constellation and manifests itself as a featureless, hazy band through the neighboring constellations of Gemini and Monoceros. Or ...
