What is the Universe made of?
... to scientists. One possibility for this additional energy is “quintessence”, a fifth fundamental force to go with gravity, the two nuclear forces and the electromagnetic force. This fifth force could be responsible for accelerating the rate of expansion of the Universe. Einstein was the first to int ...
... to scientists. One possibility for this additional energy is “quintessence”, a fifth fundamental force to go with gravity, the two nuclear forces and the electromagnetic force. This fifth force could be responsible for accelerating the rate of expansion of the Universe. Einstein was the first to int ...
Lecture 2. Isolated Neutron Stars – I.
... How to find new candidates? 1. Digging the data Many attempts failed. One of the latest used SDSS optical data together with ROSAT X-ray. Candidates have been observed by Chandra. Nothing was found (Agueros et al. arXiv: 1103.2132). 2. eROSITA is coming! In 2014 spectrum-RG with eROSITA will be lau ...
... How to find new candidates? 1. Digging the data Many attempts failed. One of the latest used SDSS optical data together with ROSAT X-ray. Candidates have been observed by Chandra. Nothing was found (Agueros et al. arXiv: 1103.2132). 2. eROSITA is coming! In 2014 spectrum-RG with eROSITA will be lau ...
Orbits and Dark Matter, the Center of the Milky Way
... Does have mass, produces gravity Nature is unknown Might be normal matter in a form that doesn’t emit much light – very small and dim star, little black holes • More likely it is elementary particles other than normal matter ...
... Does have mass, produces gravity Nature is unknown Might be normal matter in a form that doesn’t emit much light – very small and dim star, little black holes • More likely it is elementary particles other than normal matter ...
Pulsars - Chabot College
... accidentally discovered a pulsing radio source Sharp pulse every 1.3 sec. ~1000 light years away Called it a “pulsar”, but what was it? ...
... accidentally discovered a pulsing radio source Sharp pulse every 1.3 sec. ~1000 light years away Called it a “pulsar”, but what was it? ...
Test #4 (Ch. 13-16) ASTR 10 You have 1 hour to take the exam, and
... You have 1 hour to take the exam, and you can keep your copy of the test once you’re done. A list of answers to this exam will post to the course website next week, so you can have feedback on the exam before the final. 1. Which two processes can generate energy to help a star maintain its internal ...
... You have 1 hour to take the exam, and you can keep your copy of the test once you’re done. A list of answers to this exam will post to the course website next week, so you can have feedback on the exam before the final. 1. Which two processes can generate energy to help a star maintain its internal ...
Nature paper - University of Southampton
... binaries, contains neutron stars that accrete material from a more massive companion star5. The two subpopulations are most probably associated with the two distinct types of neutron-starforming supernova, with electron-capture supernovae preferentially producing systems with short spin periods, sho ...
... binaries, contains neutron stars that accrete material from a more massive companion star5. The two subpopulations are most probably associated with the two distinct types of neutron-starforming supernova, with electron-capture supernovae preferentially producing systems with short spin periods, sho ...
Ch. 18
... • Contrast X-ray bursters with novae on white dwarfs. • Novae occur when hydrogen fusion suddenly ignites on the surface of a white dwarf in a binary system. In contrast, hydrogen fusion is steady on the surface of a neutron star in a binary system. However, the steady hydrogen burning builds up a l ...
... • Contrast X-ray bursters with novae on white dwarfs. • Novae occur when hydrogen fusion suddenly ignites on the surface of a white dwarf in a binary system. In contrast, hydrogen fusion is steady on the surface of a neutron star in a binary system. However, the steady hydrogen burning builds up a l ...
Published by the Association Pro ISSI No. 37, May 2016
... reaction releases huge amounts of energy heating the core further up to several million K. This makes the protostar become a veritable shining star. Of the various chapters of a star’s biography, hydrogen fusion is by far the longest. Its duration depends on the star’s size: the larger the mass, the ...
... reaction releases huge amounts of energy heating the core further up to several million K. This makes the protostar become a veritable shining star. Of the various chapters of a star’s biography, hydrogen fusion is by far the longest. Its duration depends on the star’s size: the larger the mass, the ...
AN INTRODUCTION TO ASTRONOMY Dr. Uri Griv Department of Physics, Ben-Gurion University
... AN INTRODUCTION TO ASTRONOMY Dr. Uri Griv Department of Physics, Ben-Gurion University Tel.: 08-6428226 Email: [email protected] ...
... AN INTRODUCTION TO ASTRONOMY Dr. Uri Griv Department of Physics, Ben-Gurion University Tel.: 08-6428226 Email: [email protected] ...
UNIVERSITY OF SOUTHAMPTON PHYS2013W1 SEMESTER 1
... Section A carries 1/3 of the total marks for the exam paper and you should aim to spend about 40 mins on it. Section B carries 2/3 of the total marks for the exam paper and you should aim to spend about 80 mins on it. A Sheet of Physical Constants will be provided with this examination paper. An out ...
... Section A carries 1/3 of the total marks for the exam paper and you should aim to spend about 40 mins on it. Section B carries 2/3 of the total marks for the exam paper and you should aim to spend about 80 mins on it. A Sheet of Physical Constants will be provided with this examination paper. An out ...
Neutron Stars and Black Holes
... allowed the host galaxies to be identified and distances to be measured. • The luminosities of these things are HUGE: 1052 ergs/s. Equivalent to vaporizing a star into pure energy in a matter of 10 seconds. • Also highly beamed and relativistic (indicating jets moving near the speed of light) • Now ...
... allowed the host galaxies to be identified and distances to be measured. • The luminosities of these things are HUGE: 1052 ergs/s. Equivalent to vaporizing a star into pure energy in a matter of 10 seconds. • Also highly beamed and relativistic (indicating jets moving near the speed of light) • Now ...
HEA_Pulsars
... This rate of energy loss is comparable to that inferred from the observed emission, for example in the 2-20keV range, the observed luminosity in the Crab Nebula is approx. ...
... This rate of energy loss is comparable to that inferred from the observed emission, for example in the 2-20keV range, the observed luminosity in the Crab Nebula is approx. ...
Sample Final
... 37. When the signals from pulsars were first discovered, they were thought to be a) Mass exchange between a normal star and a white dwarf. b) Mass exchange between a normal star and a black hole. c) Signals from an extraterrestrial intelligence. d) Stars in the process of collapsing down to a black ...
... 37. When the signals from pulsars were first discovered, they were thought to be a) Mass exchange between a normal star and a white dwarf. b) Mass exchange between a normal star and a black hole. c) Signals from an extraterrestrial intelligence. d) Stars in the process of collapsing down to a black ...
Gravity simplest fusion
... • When a neutron star forms, the pull of gravity is so great that it overrides the electron degeneracy pressure of the atoms of the star. • The electrons are forced into their respective nuclei, where they combine with protons to form neutrons. This greatly decreases the size of each atom, and allow ...
... • When a neutron star forms, the pull of gravity is so great that it overrides the electron degeneracy pressure of the atoms of the star. • The electrons are forced into their respective nuclei, where they combine with protons to form neutrons. This greatly decreases the size of each atom, and allow ...
Powerpoint
... Millisecond pulsars: periods of 1 to a few msec. Probably accreted matter from a binary companion that made it spin faster. Gamma-ray Bursts: some pulsars produce bursts of gamma-rays, ...
... Millisecond pulsars: periods of 1 to a few msec. Probably accreted matter from a binary companion that made it spin faster. Gamma-ray Bursts: some pulsars produce bursts of gamma-rays, ...
Cosmic Collisions
... scattered in random directions, but gravity acts so gradually that planetary orbits are not disturbed. A collision takes about a billion years; during the last billion years, life on Earth evolved from single-celled organisms to amazingly primative apes who still think digital watches are pretty nea ...
... scattered in random directions, but gravity acts so gradually that planetary orbits are not disturbed. A collision takes about a billion years; during the last billion years, life on Earth evolved from single-celled organisms to amazingly primative apes who still think digital watches are pretty nea ...
Death of sun
... build up in their cores. High mass stars can form elements up to iron before fusion stops. ...
... build up in their cores. High mass stars can form elements up to iron before fusion stops. ...
How is the Potential Energy Released
... the stellar surface. Some of this is used to spin up the star, but there remains an amount GMMx/2R(1- ωk/Ωk)2 which is radiated ...
... the stellar surface. Some of this is used to spin up the star, but there remains an amount GMMx/2R(1- ωk/Ωk)2 which is radiated ...
FEEDBACK IN THE LOCAL UNIVERSE: The
... cavities (in blue). Such correspondence is typical of cool core clusters with cavities and extended radio sources, presenting strong circumstantial evidence in support of the AGN feedback model. See Bîrzan et al. (2004) for a comprehensive census of the currently known X-ray cavity systems in groups ...
... cavities (in blue). Such correspondence is typical of cool core clusters with cavities and extended radio sources, presenting strong circumstantial evidence in support of the AGN feedback model. See Bîrzan et al. (2004) for a comprehensive census of the currently known X-ray cavity systems in groups ...
Non-thermal hard X-ray emission from stellar coronae
... “Space weather” effects on planetary systems ...
... “Space weather” effects on planetary systems ...
Handout 30
... What does increased temperature from contraction in the core cause the helium core to do? ...
... What does increased temperature from contraction in the core cause the helium core to do? ...
Stellar Evolution
... get high enough to fuse carbon, so no more energy is produced. The outer layers of gas expand and are driven off. This gas is called a planetary nebula. Only the core is left which is a white hot ball of carbon called a white dwarf. ...
... get high enough to fuse carbon, so no more energy is produced. The outer layers of gas expand and are driven off. This gas is called a planetary nebula. Only the core is left which is a white hot ball of carbon called a white dwarf. ...
Astrophysical X-ray source
Astrophysical X-ray sources are astronomical objects with physical properties which result in the emission of X-rays.There are a number of types of astrophysical objects which emit X-rays, from galaxy clusters, through black holes in active galactic nuclei (AGN) to galactic objects such as supernova remnants, stars, and binary stars containing a white dwarf (cataclysmic variable stars and super soft X-ray sources), neutron star or black hole (X-ray binaries). Some solar system bodies emit X-rays, the most notable being the Moon, although most of the X-ray brightness of the Moon arises from reflected solar X-rays. A combination of many unresolved X-ray sources is thought to produce the observed X-ray background. The X-ray continuum can arise from bremsstrahlung, either magnetic or ordinary Coulomb, black-body radiation, synchrotron radiation, inverse Compton scattering of lower-energy photons be relativistic electrons, knock-on collisions of fast protons with atomic electrons, and atomic recombination, with or without additional electron transitions.Furthermore, celestial entities in space are discussed as celestial X-ray sources. The origin of all observed astronomical X-ray sources is in, near to, or associated with a coronal cloud or gas at coronal cloud temperatures for however long or brief a period.