Black Holes
... • After studying these stars, she witnessed a disappearance of one of the stars that was, at the time, the closest object to the Black Hole. • Whether the star was sucked up by the Black Hole or just went behind it, Scientists will never know. ...
... • After studying these stars, she witnessed a disappearance of one of the stars that was, at the time, the closest object to the Black Hole. • Whether the star was sucked up by the Black Hole or just went behind it, Scientists will never know. ...
Chapter 1 Introduction
... Due to the immense amount of potential energy released as radiation, accretion ows can be some of the most luminous objects in the universe. Quiescent SMBHs like Sgr A*, however, emit at many orders of magnitude less than the Eddington luminosity. It is difficult to observe quiescent SMBHs, including ...
... Due to the immense amount of potential energy released as radiation, accretion ows can be some of the most luminous objects in the universe. Quiescent SMBHs like Sgr A*, however, emit at many orders of magnitude less than the Eddington luminosity. It is difficult to observe quiescent SMBHs, including ...
Lecture 16: Iron Core Collapse, Neutron Stars, and Nucleosynthesis
... 15 solar masses. The shock is born near 0.7 solar masses. Initially the bounce gives it positive kinetic energy, but for each 0.1 solar masses it traverses and photodisintegrates about 1051 erg of energy is lost. Additional energy is lost to neutrinos as theρshock ≈ 1011 moves to low densities, ...
... 15 solar masses. The shock is born near 0.7 solar masses. Initially the bounce gives it positive kinetic energy, but for each 0.1 solar masses it traverses and photodisintegrates about 1051 erg of energy is lost. Additional energy is lost to neutrinos as theρshock ≈ 1011 moves to low densities, ...
Get document
... The integrated spectra of stellar systems, like galaxies and star clusters, contain an extraordinary amount of information, and its analysis can reveal fundamental parameters such as metallicity, age and star formation history. A method that is widely used today is the analysis of the integrated spe ...
... The integrated spectra of stellar systems, like galaxies and star clusters, contain an extraordinary amount of information, and its analysis can reveal fundamental parameters such as metallicity, age and star formation history. A method that is widely used today is the analysis of the integrated spe ...
Sec 29.3 - Highland High School
... Supernova formation A star that begins with a mass between about 8 and 20 times the Sun’s mass will end up with a core that is too massive to be supported by electron pressure. Once reactions in the core of the star have created iron, no further energy-producing reactions can occur, and the core of ...
... Supernova formation A star that begins with a mass between about 8 and 20 times the Sun’s mass will end up with a core that is too massive to be supported by electron pressure. Once reactions in the core of the star have created iron, no further energy-producing reactions can occur, and the core of ...
vuorinen_neutron_stars
... phase transition to quark matter, witness strong correlation between and the chemical potential at the center of a maximally massive star. The stronger the transition, the less room for quark matter. Even then the pQCD result crucial for constraining the EoS! ...
... phase transition to quark matter, witness strong correlation between and the chemical potential at the center of a maximally massive star. The stronger the transition, the less room for quark matter. Even then the pQCD result crucial for constraining the EoS! ...
Document
... proposed. One of the most promising models is magnetohydorodynamic (MHD) acceleration from accretion disks. We develop the CIP-MOCCT scheme to three-dimensional cylindrical code and solve the interaction between an accretion disk and a large-scale magnetic field. To investigate the stability of the ...
... proposed. One of the most promising models is magnetohydorodynamic (MHD) acceleration from accretion disks. We develop the CIP-MOCCT scheme to three-dimensional cylindrical code and solve the interaction between an accretion disk and a large-scale magnetic field. To investigate the stability of the ...
Study of the X-ray Source Population and the Dark Matter
... The existence of X-ray binaries in these galaxies, if confirmed, would indicate that these galaxies are able to retain their compact objects, which are believed to obtain high kick velocities at their birth in asymmetric supernova explosions. Therefore, the search for and the study of X-ray sources ...
... The existence of X-ray binaries in these galaxies, if confirmed, would indicate that these galaxies are able to retain their compact objects, which are believed to obtain high kick velocities at their birth in asymmetric supernova explosions. Therefore, the search for and the study of X-ray sources ...
Neutron Stars
... • Nova is a faint star suddenly brightens by a factor of 104 to 108 over a few days or hours • It reaches a peak luminosity of about 105 Lsun • A nova is different from supernova (luminosity of 109 Lsun) • Material from an ordinary star in a close binary can fall onto the surface of the companion wh ...
... • Nova is a faint star suddenly brightens by a factor of 104 to 108 over a few days or hours • It reaches a peak luminosity of about 105 Lsun • A nova is different from supernova (luminosity of 109 Lsun) • Material from an ordinary star in a close binary can fall onto the surface of the companion wh ...
Earth Science 25.2A : Stellar Evolution
... The red giant stage occurs because the zone of hydrogen fusion continually moves outward, leaving behind a helium core. Eventually, all the hydrogen in the star’s core is consumed. While hydrogen fusion is still occurring in the star’s outer shell, no fusion is taking place in the inner core. ...
... The red giant stage occurs because the zone of hydrogen fusion continually moves outward, leaving behind a helium core. Eventually, all the hydrogen in the star’s core is consumed. While hydrogen fusion is still occurring in the star’s outer shell, no fusion is taking place in the inner core. ...
type II supernova
... starts moving up towards the stars surface. A shock wave of tremendous energy is generated moving at supersonic speeds (5-10 000km s-1) blowing off the rest of the star's outer layers. The neutrinos produced by inverse beta decay swiftly travel out of the core, carrying up to 100 times more energy t ...
... starts moving up towards the stars surface. A shock wave of tremendous energy is generated moving at supersonic speeds (5-10 000km s-1) blowing off the rest of the star's outer layers. The neutrinos produced by inverse beta decay swiftly travel out of the core, carrying up to 100 times more energy t ...
Star A
... objects emitting the lines are in orbit. Media Clip In the more common single-line systems, one star is too faint for its spectrum to be distinguished, so we see only one set of lines shifting back and forth. This shifting means that the detected star must be in orbit around another star, even thoug ...
... objects emitting the lines are in orbit. Media Clip In the more common single-line systems, one star is too faint for its spectrum to be distinguished, so we see only one set of lines shifting back and forth. This shifting means that the detected star must be in orbit around another star, even thoug ...
The amazing lives of two stars
... trillions of volts that enable charged particles to race away from the star's surface. Magnetic field lines channel the particles into two narrow beams that shoot out in opposite directions and emit a stream of electromagnetic energy, in frequencies from radio to X ray. These beams sweep around spac ...
... trillions of volts that enable charged particles to race away from the star's surface. Magnetic field lines channel the particles into two narrow beams that shoot out in opposite directions and emit a stream of electromagnetic energy, in frequencies from radio to X ray. These beams sweep around spac ...
Investigating Supernova Remnants - Chandra X
... then contract in repeating cycles with periods ranging from several months to more than a year. The material ejected by the star forms a planetary nebula which expands into the surrounding interstellar medium at ~17to35 km/s. The core of the star left in the center of the planetary nebula is called ...
... then contract in repeating cycles with periods ranging from several months to more than a year. The material ejected by the star forms a planetary nebula which expands into the surrounding interstellar medium at ~17to35 km/s. The core of the star left in the center of the planetary nebula is called ...
Lecture 4 Hydrostatic equilibrium
... The interpretation of these results is the usual: they are obviously not accurate estimates of the central pressure or temperature of a star, but they provide an order of magnitude. After all, without any prior knowledge it would be difficult to guess whether the central pressure of the Sun was 1010 ...
... The interpretation of these results is the usual: they are obviously not accurate estimates of the central pressure or temperature of a star, but they provide an order of magnitude. After all, without any prior knowledge it would be difficult to guess whether the central pressure of the Sun was 1010 ...
Star formation and Evolution
... In the Milky Way we see stars at every stage of its evolution, some stars as old as the universe, 13 billions, sun with 4.5 billion years, star clusters a few million years old, and stars which are just forming. At the beginning, shortly after its formation, the Universe was made out of about 92% hy ...
... In the Milky Way we see stars at every stage of its evolution, some stars as old as the universe, 13 billions, sun with 4.5 billion years, star clusters a few million years old, and stars which are just forming. At the beginning, shortly after its formation, the Universe was made out of about 92% hy ...
DTU9ePPTChap13 - Faculty Lounge : Astronomy
... The core of a high-mass main-sequence star containing between 8 and 25 solar masses becomes a neutron star. The cores of slightly more massive stars may become quark stars. A neutron star is a very dense stellar corpse consisting of closely packed neutrons in a sphere roughly 20 km in diameter. The ...
... The core of a high-mass main-sequence star containing between 8 and 25 solar masses becomes a neutron star. The cores of slightly more massive stars may become quark stars. A neutron star is a very dense stellar corpse consisting of closely packed neutrons in a sphere roughly 20 km in diameter. The ...
AST 301 Introduction to Astronomy - University of Texas Astronomy
... If the collapsing core of a red giant has a mass greater than 4 Msun the repulsion of tightly packed neutrons can’t stop the collapse. (It may not stop the collapse of 3 Msun cores.) Once the core contracts to less than about 5 km radius, the escape speed becomes greater than the speed of light. Wha ...
... If the collapsing core of a red giant has a mass greater than 4 Msun the repulsion of tightly packed neutrons can’t stop the collapse. (It may not stop the collapse of 3 Msun cores.) Once the core contracts to less than about 5 km radius, the escape speed becomes greater than the speed of light. Wha ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.