Introduction
... which stars die depends on their original mass. In low and intermediate mass stars (∼18 M ) death is preceded by the so-called planetary nebula phase. Our Sun will become a Planetary Nebula in some 5 billion years. Because by far most stars have masses below 8 M , the planetary nebula phase must b ...
... which stars die depends on their original mass. In low and intermediate mass stars (∼18 M ) death is preceded by the so-called planetary nebula phase. Our Sun will become a Planetary Nebula in some 5 billion years. Because by far most stars have masses below 8 M , the planetary nebula phase must b ...
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... its vicinity, growing bigger with time (see figure, top). X-ray observations of rich clusters reveal a hot intergalactic gas (10 million to 100 million K) within them, containing as much (or more) mass as the galaxies themselves (see figure, bottom). The gas is clumped in some clusters, while in oth ...
... its vicinity, growing bigger with time (see figure, top). X-ray observations of rich clusters reveal a hot intergalactic gas (10 million to 100 million K) within them, containing as much (or more) mass as the galaxies themselves (see figure, bottom). The gas is clumped in some clusters, while in oth ...
Galactic spiral structure - Proceedings of the Royal Society A
... We describe the structure and composition of six major stellar streams in a population of 20 574 local stars in the New Hipparcos Reduction with known radial velocities. We find that, once fast moving stars are excluded, almost all stars belong to one of these streams. The results of our investigatio ...
... We describe the structure and composition of six major stellar streams in a population of 20 574 local stars in the New Hipparcos Reduction with known radial velocities. We find that, once fast moving stars are excluded, almost all stars belong to one of these streams. The results of our investigatio ...
Chapter 11
... Summary of Chapter 11 • Interstellar medium is made of gas and dust. • Emission nebulae are hot, glowing gas associated with the formation of large stars. • Dark dust clouds, especially molecular clouds, are very cold. They may seed the beginnings of star formation. • Dark clouds can be studied usi ...
... Summary of Chapter 11 • Interstellar medium is made of gas and dust. • Emission nebulae are hot, glowing gas associated with the formation of large stars. • Dark dust clouds, especially molecular clouds, are very cold. They may seed the beginnings of star formation. • Dark clouds can be studied usi ...
The masses of stars
... Professor Carolin Crawford This talk concerns stars, the most easily observable objects in the night sky. The nearest to us − and the most easily studied example − is the Sun, which will be a topic for one of next year’s lectures. They are all massive spheres of gas that exist in the form of stars f ...
... Professor Carolin Crawford This talk concerns stars, the most easily observable objects in the night sky. The nearest to us − and the most easily studied example − is the Sun, which will be a topic for one of next year’s lectures. They are all massive spheres of gas that exist in the form of stars f ...
GRADE 12A: Physics 7
... • The nearest major galaxy to the Milky Way is the Andromeda galaxy (Andromeda nebula), which is also a spiral. • Even the nearest galaxy lies at a distance of a few million light-years. Light reaching us has been in transit for this time, so it carries information about the galaxy as it was a few m ...
... • The nearest major galaxy to the Milky Way is the Andromeda galaxy (Andromeda nebula), which is also a spiral. • Even the nearest galaxy lies at a distance of a few million light-years. Light reaching us has been in transit for this time, so it carries information about the galaxy as it was a few m ...
Full Poster - Cool Cosmos
... vastness of space. Light may travel for billions of years before reaching our telescopes. Astronomy is primarily a science where we cannot retrieve samples, study objects in a laboratory, or physically enter an environment for detailed study. Fortunately, light carries a lot of information. By detec ...
... vastness of space. Light may travel for billions of years before reaching our telescopes. Astronomy is primarily a science where we cannot retrieve samples, study objects in a laboratory, or physically enter an environment for detailed study. Fortunately, light carries a lot of information. By detec ...
When is star formation episodic? A delay differential equation
... negative feedback with a delay. When the feedback is instantaneous, solutions approach a self-limiting equilibrium state. When there is a delay, even though the feedback is negative, the solutions can exhibit cyclic and episodic solutions. We find that periodic or episodic star formation only occurs ...
... negative feedback with a delay. When the feedback is instantaneous, solutions approach a self-limiting equilibrium state. When there is a delay, even though the feedback is negative, the solutions can exhibit cyclic and episodic solutions. We find that periodic or episodic star formation only occurs ...
galaxy formation and evolution - Yale Astronomy
... progressively larger ones, possibly in a hierarchical fashion; the galaxies that we now observe may then just represent the smallest structures that have survived as discrete units (Peebles 1974). The detailed way in which structure develops and galaxies form depends on the nature of the initial den ...
... progressively larger ones, possibly in a hierarchical fashion; the galaxies that we now observe may then just represent the smallest structures that have survived as discrete units (Peebles 1974). The detailed way in which structure develops and galaxies form depends on the nature of the initial den ...
To Be or Not to Be: The Mysteries of Disk Formation Around Rapidly
... • K-band interferometric observations of four classical Be stars (2003 – 2005) • Moderate to long baselines • CHARA Classic beam combiner • Observations interposed with calibrator stars with known angular diameter in order to transform instrumental fringe visibility into absolute visibility V • V = ...
... • K-band interferometric observations of four classical Be stars (2003 – 2005) • Moderate to long baselines • CHARA Classic beam combiner • Observations interposed with calibrator stars with known angular diameter in order to transform instrumental fringe visibility into absolute visibility V • V = ...
Cosmic variance in [O/Fe] in the Galactic disk
... We examine the distribution of the [O/Fe] abundance ratio in stars across the Galactic disk using H-band spectra from the Apache Point Galactic Evolution Experiment (APOGEE). We minimize systematic errors by considering groups of stars with similar atmospheric parameters. The APOGEE measurements in ...
... We examine the distribution of the [O/Fe] abundance ratio in stars across the Galactic disk using H-band spectra from the Apache Point Galactic Evolution Experiment (APOGEE). We minimize systematic errors by considering groups of stars with similar atmospheric parameters. The APOGEE measurements in ...
Why there are apparently so few debris disks among post
... 1) No new disks or debris disks have been found up to an age of 30 Myr suggesting that the disk material, if present before, have been consumed quite rapidly, suggesting an eventual rapid planetary formation. 2) The important phase of the disk evolution characterized by the presence of a debris disk ...
... 1) No new disks or debris disks have been found up to an age of 30 Myr suggesting that the disk material, if present before, have been consumed quite rapidly, suggesting an eventual rapid planetary formation. 2) The important phase of the disk evolution characterized by the presence of a debris disk ...
sections 16-18 instructor notes
... For disk stars that are not drifting either perpendicular to the Galactic plane or in the direction of the Galactic centre, it is reasonable to expect that: ≡ 0 and ≡ 0.
However, ≠ 0 since a typical group of stars selected
observationally will always tend to lag behind the solar
LSR. ...
... For disk stars that are not drifting either perpendicular to the Galactic plane or in the direction of the Galactic centre, it is reasonable to expect that: ≡ 0 and
The First Galaxies: Assembly under Radiative Feedback from the
... 1996; Barkana & Loeb 1999). The increased pressure in the IGM impedes the accretion of gas onto these low-mass halos, an effect known as Jeans-filtering (e.g., Shapiro et al. 1994; Gnedin & Hui 1998; Okamoto et al. 2008). In contrast, star formation inside the first dwarf galaxies should be more rob ...
... 1996; Barkana & Loeb 1999). The increased pressure in the IGM impedes the accretion of gas onto these low-mass halos, an effect known as Jeans-filtering (e.g., Shapiro et al. 1994; Gnedin & Hui 1998; Okamoto et al. 2008). In contrast, star formation inside the first dwarf galaxies should be more rob ...
Kinematics of Arp 270: gas flows, nuclear activity
... variety of new observational results are needed to help clarify them. There is also evidence for the existence of triggered star forma E-mail: [email protected] ...
... variety of new observational results are needed to help clarify them. There is also evidence for the existence of triggered star forma E-mail: [email protected] ...
GALAXY FORMATION AND CLUSTER FORMATION Richard B
... mostly within the first few Gyr. They must therefore have been more compact than typical present-day irregular or spiral galaxies, since a higher star formation rate requires a higher mean density (Larson 1977). Typical irregular or spiral galaxies also do not make clusters as massive as typical glo ...
... mostly within the first few Gyr. They must therefore have been more compact than typical present-day irregular or spiral galaxies, since a higher star formation rate requires a higher mean density (Larson 1977). Typical irregular or spiral galaxies also do not make clusters as massive as typical glo ...
Is Draco II one of the faintest dwarf galaxies? First study from Keck
... driven mainly by the change of log g along the RGB and that this star is consequently as metal-poor as NGC 2419. It further implies that star 10, with a CaT equivalent width of only 0.75 ± 0.21 is significantly more metal-poor than NGC 2419. Furthermore, the stark difference between the spectra of s ...
... driven mainly by the change of log g along the RGB and that this star is consequently as metal-poor as NGC 2419. It further implies that star 10, with a CaT equivalent width of only 0.75 ± 0.21 is significantly more metal-poor than NGC 2419. Furthermore, the stark difference between the spectra of s ...
The dense gas mass fraction in the W51 cloud and its protoclusters
... nondetection of H2 CO emission implies that the emission detected in other galaxies, e.g. Arp 220, comes from high-density gas that is not directly affiliated with already-formed massive stars. Either the non-star-forming ISM of these galaxies is very dense, implying the star formation density thres ...
... nondetection of H2 CO emission implies that the emission detected in other galaxies, e.g. Arp 220, comes from high-density gas that is not directly affiliated with already-formed massive stars. Either the non-star-forming ISM of these galaxies is very dense, implying the star formation density thres ...
THE NEW GALAXY: Signatures of Its Formation
... maybe a thousand events to reach solar metallicities. We wish to stress that [Fe/H] is not a clock: Rather it is a measure of supernova occurrences and the depth of the different potential wells that a given parcel of gas has explored. During the latter stages of the Golden Age, most of the baryons ...
... maybe a thousand events to reach solar metallicities. We wish to stress that [Fe/H] is not a clock: Rather it is a measure of supernova occurrences and the depth of the different potential wells that a given parcel of gas has explored. During the latter stages of the Golden Age, most of the baryons ...
Document
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
The dynamical lives of high redshift galaxies - dragons
... at some early point in its history. This fact is responsible for some of the major questions in extragalactic astronomy including: when did this process occur and what were the responsible ionizing sources? Recent observations have begun to provide preliminary answers to this question (e.g. Fan et a ...
... at some early point in its history. This fact is responsible for some of the major questions in extragalactic astronomy including: when did this process occur and what were the responsible ionizing sources? Recent observations have begun to provide preliminary answers to this question (e.g. Fan et a ...
Planck early results. XIX. All-sky temperature and dust optical depth
... To measure the amount and distribution of the molecular ISM, as well as the cold atomic ISM, other tracers of the interstellar gas are required. At least three tracers have been used in the past. These are UV absorption in Werner bands of H2 , infrared emission from dust, and γ-ray emission from pio ...
... To measure the amount and distribution of the molecular ISM, as well as the cold atomic ISM, other tracers of the interstellar gas are required. At least three tracers have been used in the past. These are UV absorption in Werner bands of H2 , infrared emission from dust, and γ-ray emission from pio ...
Document
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
... 2. Microlensing on isolated stellar mass BHs • There are several good candidates • But it is necessary to find the black hole ITSELF! 3. Exotic emission mechanisms • As all other exotics: interesting, but not very probable • If it works, then GLAST will show us isolated BHs 4. Runaway stars • A rare ...
uniview glossary - DMNS Galaxy Guide Portal
... Neptune has a series of dark spots, believed to represent holes in its methane cloud. The first of these was discovered in 1989, by Voyager 2, and named the Great Dark Spot, similar to the Great Red Spot of Jupiter. Hubble views in 1994 showed that this spot had disappeared, but other dark spots app ...
... Neptune has a series of dark spots, believed to represent holes in its methane cloud. The first of these was discovered in 1989, by Voyager 2, and named the Great Dark Spot, similar to the Great Red Spot of Jupiter. Hubble views in 1994 showed that this spot had disappeared, but other dark spots app ...