Chapter 19 Star Formation
... At stage 6, the core reaches 10 million K, and nuclear fusion begins. The protostar has become a star. The star continues to contract and increase in temperature until it is in equilibrium: Internal pressure force outward, balancing the inward force of gravity, at every layer of the star’s interior. ...
... At stage 6, the core reaches 10 million K, and nuclear fusion begins. The protostar has become a star. The star continues to contract and increase in temperature until it is in equilibrium: Internal pressure force outward, balancing the inward force of gravity, at every layer of the star’s interior. ...
Halo Substructure and the Power Spectrum
... particular, Dalal and Kochanek [9] (DK) considered bounds on the PPS. As such, it is important to understand the theoretical predictions for halo substructure as a function of the PPS and, more generally, substructure distributions and characteristics as a function of cosmology. Our results on the s ...
... particular, Dalal and Kochanek [9] (DK) considered bounds on the PPS. As such, it is important to understand the theoretical predictions for halo substructure as a function of the PPS and, more generally, substructure distributions and characteristics as a function of cosmology. Our results on the s ...
Asymmetric Star Formation Efficiency Due to Ram Pressure Stripping
... matter haloes, depending on how they have cooled and whether they reach a density greater than a certain threshold, they can be converted into star particles or not. The rate at which stars are formed is determined by the thermodynamic conditions of the medium. The simulations follow different feedb ...
... matter haloes, depending on how they have cooled and whether they reach a density greater than a certain threshold, they can be converted into star particles or not. The rate at which stars are formed is determined by the thermodynamic conditions of the medium. The simulations follow different feedb ...
Hydrostatic equilibrium in a magnetized, warped Galactic disc
... regular and random magnetic fields contain disc and halo components, the parameters of which we have determined. The layer at 1 & |z| & 4 kpc can be overpressured and an outflow at a speed of about 50 km s21 may occur there, presumably associated with a Galactic fountain flow, if B0 . 2 mG. We show ...
... regular and random magnetic fields contain disc and halo components, the parameters of which we have determined. The layer at 1 & |z| & 4 kpc can be overpressured and an outflow at a speed of about 50 km s21 may occur there, presumably associated with a Galactic fountain flow, if B0 . 2 mG. We show ...
All About MACHO
... dark matter candidates. It is quite natural that some type of exotic, weakly interacting elementary particle would be left over from the Big Bang with an abundance appropriate to make up the dark matter. The two most popular classes of candidates are the axion and the Weakly Interacting Massive Part ...
... dark matter candidates. It is quite natural that some type of exotic, weakly interacting elementary particle would be left over from the Big Bang with an abundance appropriate to make up the dark matter. The two most popular classes of candidates are the axion and the Weakly Interacting Massive Part ...
Section 15
... X, Y (≃ 1 − X) are the abundances by mass of hydrogen and helium, χ(H2 ) is the dissociation energy of molecular hydrogen (4.5 eV), and χ(H), χ(He) are the ionization potentials of hydrogen and helium (13.6 eV, and 24.6+54.4 eV), ...
... X, Y (≃ 1 − X) are the abundances by mass of hydrogen and helium, χ(H2 ) is the dissociation energy of molecular hydrogen (4.5 eV), and χ(H), χ(He) are the ionization potentials of hydrogen and helium (13.6 eV, and 24.6+54.4 eV), ...
1. Seyfert Galaxies
... and [N I] to highly ionized cases such as [Ne V] and [O VI]. Even hot stars cannot ionize gas as highly as these ions require, so that both a strong source of hard radiation and a wide range in gas density must be present to see such spectra. ...
... and [N I] to highly ionized cases such as [Ne V] and [O VI]. Even hot stars cannot ionize gas as highly as these ions require, so that both a strong source of hard radiation and a wide range in gas density must be present to see such spectra. ...
the printable Observing Olympics Object Info Sheet in pdf
... nebula has been expanding at a constant rate of 10 milli-arcseconds a year, then it would take 1000 ± 260 years to reach a diameter of 20 arcseconds. This may be an upper limit to the age, because ejected material will be slowed when it encounters material ejected from the star at earlier stages of ...
... nebula has been expanding at a constant rate of 10 milli-arcseconds a year, then it would take 1000 ± 260 years to reach a diameter of 20 arcseconds. This may be an upper limit to the age, because ejected material will be slowed when it encounters material ejected from the star at earlier stages of ...
Syllabus - University of Texas Rio Grande Valley
... sexual harassment about which she/he becomes aware during this course through writing, discussion, or personal disclosure. More information can be found at www.utrgv.edu/equity, including confidential resources available on campus. The faculty and staff of UTRGV actively strive to provide a learning ...
... sexual harassment about which she/he becomes aware during this course through writing, discussion, or personal disclosure. More information can be found at www.utrgv.edu/equity, including confidential resources available on campus. The faculty and staff of UTRGV actively strive to provide a learning ...
Dynamical models of the nucleus of M31
... relaxation (details depend on age of stars) • vector resonant relaxation conserves semi-major axis and eccentricity but not the direction of orbit normal • preliminary models suggest that some or all of the curious features of the stellar distribution in the Galactic center arise naturally in therma ...
... relaxation (details depend on age of stars) • vector resonant relaxation conserves semi-major axis and eccentricity but not the direction of orbit normal • preliminary models suggest that some or all of the curious features of the stellar distribution in the Galactic center arise naturally in therma ...
FINAL PROGRAM - Drifting through the Cosmic Web
... Galactic Outflow Scaling Relations and Their Impact on Galactic Evolution ...
... Galactic Outflow Scaling Relations and Their Impact on Galactic Evolution ...
Astronomy Chapter 17 – Galaxies A. Main Ideas 1. Discovering
... parallax to measure such large distances because the angle by which the galaxy’s position changes as we move around the Sun is too small to be measured. Astronomers use the method of standard candles to measure the distance to distant galaxies. Using the inverse-square law and the known luminosity o ...
... parallax to measure such large distances because the angle by which the galaxy’s position changes as we move around the Sun is too small to be measured. Astronomers use the method of standard candles to measure the distance to distant galaxies. Using the inverse-square law and the known luminosity o ...
the life cycles of stars (5) - U3A Bendigo Courses / Activities
... sequence these stars emit material from their surface due to sheer radiation pressure. The strong light radiation carries gas with it. Our sun emits a solar wind of protons and electrons which can cause aurorae and in certain cases disrupt our electricity supply lines. In its later post main sequenc ...
... sequence these stars emit material from their surface due to sheer radiation pressure. The strong light radiation carries gas with it. Our sun emits a solar wind of protons and electrons which can cause aurorae and in certain cases disrupt our electricity supply lines. In its later post main sequenc ...
Matter Cycle in the Interstellar Medium (ISM)
... About reflection nebulae: spectrum of the Pleiades Nebula by Vesto Slipher (Lowell Obs.) ➙ replica of stellar spectra ⇒ concluded there must be reflection by “small particles” ...
... About reflection nebulae: spectrum of the Pleiades Nebula by Vesto Slipher (Lowell Obs.) ➙ replica of stellar spectra ⇒ concluded there must be reflection by “small particles” ...
the magnetic field reversal as a to a mechanism of the origin
... therefore, ""'"40'. Considering the averaged out values for the thickness of the layer and of the z distance of the spiral arm, the agreement between the two values of E is rather satisfactory. Extrapolation ol' these results to other galaxies would lead us to expect that in some galaxies spiral arm ...
... therefore, ""'"40'. Considering the averaged out values for the thickness of the layer and of the z distance of the spiral arm, the agreement between the two values of E is rather satisfactory. Extrapolation ol' these results to other galaxies would lead us to expect that in some galaxies spiral arm ...
Resultados del Concurso 2008A para Observaciones en
... Título: Disentangling the central ionization mechanism in compact group galaxies Resumen: The so-called transitional or composite galaxies are objects that sit in a transition locus between starforming (SF) galaxies and active galactic nuclei (AGN) in the BPT diagnostic diagrams. These have historic ...
... Título: Disentangling the central ionization mechanism in compact group galaxies Resumen: The so-called transitional or composite galaxies are objects that sit in a transition locus between starforming (SF) galaxies and active galactic nuclei (AGN) in the BPT diagnostic diagrams. These have historic ...
Diffuse Ultraviolet Emission in Galaxies
... of UV radiation each star produces. We focused on the hottest, most massive stars, which are the only ones capable of producing large amounts of UV radiation. We divided these stars into two groups, using their traditional names: “O-type” stars, with initial masses >20 Msun and lifespans < 5 Myr, a ...
... of UV radiation each star produces. We focused on the hottest, most massive stars, which are the only ones capable of producing large amounts of UV radiation. We divided these stars into two groups, using their traditional names: “O-type” stars, with initial masses >20 Msun and lifespans < 5 Myr, a ...
Lecture 18
... d) Perhaps massive stars don’t form from one collapsing cloud, but instead form from collisions of smaller stars? Idea: stars today never collide, but collisions would be more frequent: • In young clusters where stars form, which are much denser than the Galaxy in the Solar neighborhood. • Young st ...
... d) Perhaps massive stars don’t form from one collapsing cloud, but instead form from collisions of smaller stars? Idea: stars today never collide, but collisions would be more frequent: • In young clusters where stars form, which are much denser than the Galaxy in the Solar neighborhood. • Young st ...
Searching for Dwarf Galaxies and Population III Star
... sources is the chemically unevolved surroundings of a large galaxy or proto-cluster of galaxies at high redshift. The central sources are likely to have ionized a local “bubble” through which strong Lyman emission can escape from surrounding dwarf galaxies. Thus, near-infrared observations of thes ...
... sources is the chemically unevolved surroundings of a large galaxy or proto-cluster of galaxies at high redshift. The central sources are likely to have ionized a local “bubble” through which strong Lyman emission can escape from surrounding dwarf galaxies. Thus, near-infrared observations of thes ...
Rearrangement of gas in disc galaxies
... between star formation studied at small scales and large scales is very important to generate a complete picture. Looking at small scales, the creation of new stars is mainly influenced by the local gas density. This well-known relation was originally studied by Schmidt (1959), but it has been widel ...
... between star formation studied at small scales and large scales is very important to generate a complete picture. Looking at small scales, the creation of new stars is mainly influenced by the local gas density. This well-known relation was originally studied by Schmidt (1959), but it has been widel ...
Spiral Galaxies: Density Waves
... – Spiral waves can only grow between the inner and outer Linblad resonances (Ωp = Ω - κ/m ; Ωp = Ω + κ/m ) where κ is the epicyclic frequency and m is an integer (the # of spiral arms) ...
... – Spiral waves can only grow between the inner and outer Linblad resonances (Ωp = Ω - κ/m ; Ωp = Ω + κ/m ) where κ is the epicyclic frequency and m is an integer (the # of spiral arms) ...
No Slide Title
... 7-11.Crab Nebula-In 1054 AD the chinese recorded a bright new star seen in daylight for quite a long time.It was a Supernova and we see the remnants in these pictures.The first four show it as seen in four different regions of the electromagnetic spectrum[UV,visible,IR,X-ray].The final picture shows ...
... 7-11.Crab Nebula-In 1054 AD the chinese recorded a bright new star seen in daylight for quite a long time.It was a Supernova and we see the remnants in these pictures.The first four show it as seen in four different regions of the electromagnetic spectrum[UV,visible,IR,X-ray].The final picture shows ...
Chapter 8: The Pennsylvanian Period in Alabama: Looking Up
... resemble the galaxy shown in Fig. 8.2, bottom., known as NGC 3953 in Ursa Major. NGC 3953 is a spiral galaxy, a massive pinwheel-shaped system whose stars and interstellar material have been molded into spiral arms through the action of gravity. Although the arms of NGC 3953 are readily visible to u ...
... resemble the galaxy shown in Fig. 8.2, bottom., known as NGC 3953 in Ursa Major. NGC 3953 is a spiral galaxy, a massive pinwheel-shaped system whose stars and interstellar material have been molded into spiral arms through the action of gravity. Although the arms of NGC 3953 are readily visible to u ...
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 ...
The Pennsylvanian Period in Alabama: Looking Up Astronomy and
... resemble the galaxy shown in Fig. 8.2, bottom., known as NGC 3953 in Ursa Major. NGC 3953 is a spiral galaxy, a massive pinwheel-shaped system whose stars and interstellar material have been molded into spiral arms through the action of gravity. Although the arms of NGC 3953 are readily visible to u ...
... resemble the galaxy shown in Fig. 8.2, bottom., known as NGC 3953 in Ursa Major. NGC 3953 is a spiral galaxy, a massive pinwheel-shaped system whose stars and interstellar material have been molded into spiral arms through the action of gravity. Although the arms of NGC 3953 are readily visible to u ...