SUMSS - 京都大学
... But gas and stars are not the whole story... Some galaxies are powerful sources of radio waves. These are always giant elliptical galaxies, never spirals or dwarfs. Why?? ...
... But gas and stars are not the whole story... Some galaxies are powerful sources of radio waves. These are always giant elliptical galaxies, never spirals or dwarfs. Why?? ...
Magnetic Accretion onto Neutron Stars A crucial difference between
... rate of, say, 0.1 ṀE on a surface area only 10−3 of the star means that the local flux generated can be 100 times Eddington or more! What does that mean for this system? It means that for such accretion to persist, the radiation cannot escape back up the accretion funnel. Instead, it has to come ou ...
... rate of, say, 0.1 ṀE on a surface area only 10−3 of the star means that the local flux generated can be 100 times Eddington or more! What does that mean for this system? It means that for such accretion to persist, the radiation cannot escape back up the accretion funnel. Instead, it has to come ou ...
Universe of Learning Science Briefing: Our Home, the Milky Way
... But there are types of stars called Red Clump Giants for which we know the intrinsic brightness. They are also fairly common and bright and can be used to trace the structure of the Galaxy. These can be used to measure distances; stars twice as far away are four times fainter. ...
... But there are types of stars called Red Clump Giants for which we know the intrinsic brightness. They are also fairly common and bright and can be used to trace the structure of the Galaxy. These can be used to measure distances; stars twice as far away are four times fainter. ...
- Europhysics News
... Several types of black holes are predicted by astrophysicists. The collapse of the heart of a star whose initial mass is larger than 45 M leads to the formation of a stellar black hole. When the core is beyond 3 M , even the repulsive forces of the degenerated mat ter (electrons and neutrons) canno ...
... Several types of black holes are predicted by astrophysicists. The collapse of the heart of a star whose initial mass is larger than 45 M leads to the formation of a stellar black hole. When the core is beyond 3 M , even the repulsive forces of the degenerated mat ter (electrons and neutrons) canno ...
ASTRONOMY 5
... 3) Yet another type of active galaxy is radio galaxies. In these objects, the BHs shine in a different way by ejecting blobs of ionized, fast-moving gas mixed with magnetic fields. The electrons in the gas spiral around in the magnetic field, which causes them to emit bright synchrotron radio emissi ...
... 3) Yet another type of active galaxy is radio galaxies. In these objects, the BHs shine in a different way by ejecting blobs of ionized, fast-moving gas mixed with magnetic fields. The electrons in the gas spiral around in the magnetic field, which causes them to emit bright synchrotron radio emissi ...
Turning over a new leaf
... Despite plasma temperatures reaching a few million degrees, the corona’s low density means it yields relatively little thermal radiation. Nonetheless, the corona is responsible for most of the radio and X-ray emissions from these cool stars. The hot gases in the corona emit thermal radiation as X-ra ...
... Despite plasma temperatures reaching a few million degrees, the corona’s low density means it yields relatively little thermal radiation. Nonetheless, the corona is responsible for most of the radio and X-ray emissions from these cool stars. The hot gases in the corona emit thermal radiation as X-ra ...
Photometric Mass-to-Light Ratio In addition to a population`s total
... means that most of the stellar mass of population resides in low mass stars. ...
... means that most of the stellar mass of population resides in low mass stars. ...
PPT - Chandra X
... 3. Fit the grouped spectrum (Chi-squared data-variance statistics, Levenberg-Marquardt optimization, kT1 [0.01-2] and kT2 [1-10] keV 4. If E(B-V) is unknown, fit again with kT, NH floating 5. Freeze kT and NH; fit for abundances 6. If two temperatures have not been found or the chi-squared statistic ...
... 3. Fit the grouped spectrum (Chi-squared data-variance statistics, Levenberg-Marquardt optimization, kT1 [0.01-2] and kT2 [1-10] keV 4. If E(B-V) is unknown, fit again with kT, NH floating 5. Freeze kT and NH; fit for abundances 6. If two temperatures have not been found or the chi-squared statistic ...
Ch. 13 GALAXIES
... A. ~ ___ % of galaxies – very ______ B. Wide range of EM radiation II. Types of Active Galaxies A. ___________ galaxies – “normal” galaxies undergoing aggressive star formation due to interactions Ex/ M82 – The ______ Galaxy B. ____________ galaxies – resemble spirals, but with very energetic galact ...
... A. ~ ___ % of galaxies – very ______ B. Wide range of EM radiation II. Types of Active Galaxies A. ___________ galaxies – “normal” galaxies undergoing aggressive star formation due to interactions Ex/ M82 – The ______ Galaxy B. ____________ galaxies – resemble spirals, but with very energetic galact ...
Astronomy_Stellar_Evolution_and_Type_II_Supernovae_Exam
... collapse occurs. The unit of measurement named a “Foe” (1051 ergs) was derived to describe this : 4) Stellar remnants which, due to their very precise periods (rivaling even atomic clocks for regularity), have been useful in the indirect detection of gravitational radiation of binary star systems. 5 ...
... collapse occurs. The unit of measurement named a “Foe” (1051 ergs) was derived to describe this : 4) Stellar remnants which, due to their very precise periods (rivaling even atomic clocks for regularity), have been useful in the indirect detection of gravitational radiation of binary star systems. 5 ...
AST 301 Introduction to Astronomy - University of Texas Astronomy
... In a normal gas, the electrons’ motion is caused by heat. But at very high densities, the wave properties of the electrons become important, and the electrons must move fast even if the temperature is low. The result is that when a white dwarf loses energy, its electrons don’t slow down, so its pres ...
... In a normal gas, the electrons’ motion is caused by heat. But at very high densities, the wave properties of the electrons become important, and the electrons must move fast even if the temperature is low. The result is that when a white dwarf loses energy, its electrons don’t slow down, so its pres ...
20agn1s
... Strange Galaxies Some galaxies have a compact, powerful source of energy at their core Among the most energetic objects in the universe ...
... Strange Galaxies Some galaxies have a compact, powerful source of energy at their core Among the most energetic objects in the universe ...
Abstract
... How a galaxy began its life is one of the greatest mysteries. The recent advances in observational technique allow us to directly observe the universe 10 billion years ago and find bright young objects there. Lyman α emitters1 have been recently discovered at redshifts greater than 3 (2.1109 yr aft ...
... How a galaxy began its life is one of the greatest mysteries. The recent advances in observational technique allow us to directly observe the universe 10 billion years ago and find bright young objects there. Lyman α emitters1 have been recently discovered at redshifts greater than 3 (2.1109 yr aft ...
Faintest Star Cluster Yet Found on Outskirts of Milky Way | Globular
... that would far outshine this entire globular cluster." Muñoz spotted the minute object in observations of a mini galaxy orbiting the Milky Way called Ursa Minor. The photos were taken by the Canada-France-Hawaii Telescope on Hawaii's Mauna Kea peak. "I was looking at an old friend so to speak, the U ...
... that would far outshine this entire globular cluster." Muñoz spotted the minute object in observations of a mini galaxy orbiting the Milky Way called Ursa Minor. The photos were taken by the Canada-France-Hawaii Telescope on Hawaii's Mauna Kea peak. "I was looking at an old friend so to speak, the U ...
Cosmology: Black Holes, Dark Matter and Dark Energy
... The X-ray image of the quasar PKS 1127-145, a highly luminous source of X-rays and visible light about 10 billion light years from Earth, shows an enormous X-ray jet that extends at least a million light years from the quasar. The jet is likely due to the collision of a beam of high-energy electrons ...
... The X-ray image of the quasar PKS 1127-145, a highly luminous source of X-rays and visible light about 10 billion light years from Earth, shows an enormous X-ray jet that extends at least a million light years from the quasar. The jet is likely due to the collision of a beam of high-energy electrons ...
Ay122a&Fall&2015+16& Background&subtrac9on,&calibra9on,& analysis& &
... illuminate&the&detector&non+uniformly,&i.e.&differently&than&does&an& astronomical&source&located&at&infinity.&&&Background&is&composed&of:& • Thermal&emission&from&telescope&components& • Stray&or&scaVered&light&from&out&of&field& • Spectral&dependence&of&flat&field&paVern& • Fringes&due&to&OH&sky&e ...
... illuminate&the&detector&non+uniformly,&i.e.&differently&than&does&an& astronomical&source&located&at&infinity.&&&Background&is&composed&of:& • Thermal&emission&from&telescope&components& • Stray&or&scaVered&light&from&out&of&field& • Spectral&dependence&of&flat&field&paVern& • Fringes&due&to&OH&sky&e ...
PowerPoint 프레젠테이션
... “The best estimate of the mass of Vela X-1 is 1.86 Msun. Unfortunately, no firm constraints on the equation of state are possible since systematic deviations in the radial-velocity curve do not allow us to exclude a mass around 1.4 Msun as found for other neutron stars.” [Barziv et al. 2001] Actual ...
... “The best estimate of the mass of Vela X-1 is 1.86 Msun. Unfortunately, no firm constraints on the equation of state are possible since systematic deviations in the radial-velocity curve do not allow us to exclude a mass around 1.4 Msun as found for other neutron stars.” [Barziv et al. 2001] Actual ...
5Stars_Part_Two
... 2. When stars orbit a black hole, we can see their orbit, but not the black hole. We can infer the mass from the mass of the star and its orbit. 3. The Andromeda galaxy has stars orbiting a dark object that is 30 to 70 million times the mass of the sun. ...
... 2. When stars orbit a black hole, we can see their orbit, but not the black hole. We can infer the mass from the mass of the star and its orbit. 3. The Andromeda galaxy has stars orbiting a dark object that is 30 to 70 million times the mass of the sun. ...
Acta Polytechnica
... two-temperature thermal models. Since the merging clusters can often have shock-heated, super-hot (kT ∼ 20 keV) gas, and its contribution is not negligible in the interpretation of the hard X-ray origin, it is essential to determine the thermal component with high accuracy. This motivated us to carr ...
... two-temperature thermal models. Since the merging clusters can often have shock-heated, super-hot (kT ∼ 20 keV) gas, and its contribution is not negligible in the interpretation of the hard X-ray origin, it is essential to determine the thermal component with high accuracy. This motivated us to carr ...
Recipes for ULX formation: necessary ingredients and garnishments
... Myr (Portegies Zwart & McMillan 2002). However, we have argued that there is no longer a compelling need to invoke intermediate-mass BHs in ULXs, and that the upper mass limit is likely to be somewhere between 50 and 200M . Correspondingly, if dynamical collapse and merger processes are still neede ...
... Myr (Portegies Zwart & McMillan 2002). However, we have argued that there is no longer a compelling need to invoke intermediate-mass BHs in ULXs, and that the upper mass limit is likely to be somewhere between 50 and 200M . Correspondingly, if dynamical collapse and merger processes are still neede ...
Signatures of the first stars in the 21cm Emission and Absorption
... • Central gas cools only to T ≈ 200 K. Molecular hydrogen lines can be collisionally deexcited at density n > 104 cm-3, making the cooling rate independent of density and inhibiting fragmentation. • Jeans mass ≈ 300 Msun . • Accretion rate ≈ cs3/G ≈ 10-3 Msun/yr • The first metal-free stars were mas ...
... • Central gas cools only to T ≈ 200 K. Molecular hydrogen lines can be collisionally deexcited at density n > 104 cm-3, making the cooling rate independent of density and inhibiting fragmentation. • Jeans mass ≈ 300 Msun . • Accretion rate ≈ cs3/G ≈ 10-3 Msun/yr • The first metal-free stars were mas ...
Neutron Stars
... Periods shorter than this do not exist (such as in the previous calculation) because the object would have to rotate so fast it would overcome gravity and fly apart. ...
... Periods shorter than this do not exist (such as in the previous calculation) because the object would have to rotate so fast it would overcome gravity and fly apart. ...
Giant “Pulsar” Studies with the Compact Array Abstract
... objects from cool dwarfs to giants to pre-main sequence T Tauri stars to the hotter Ap and Bp stars, to Wolf-Rayet stars all exhibit fascinating radio properties (Güdel 2002). Add to this the generally small samples of sources of any one particular type, and exceptional variability on many timescale ...
... objects from cool dwarfs to giants to pre-main sequence T Tauri stars to the hotter Ap and Bp stars, to Wolf-Rayet stars all exhibit fascinating radio properties (Güdel 2002). Add to this the generally small samples of sources of any one particular type, and exceptional variability on many timescale ...
PH607lec12-10agn2
... Check for consistency: Schwarzschild radius is the radius where the “escape velocity” equals the speed of light around a black hole of mass M: RS = 2GM/c2 It relates mass and size! Accretion: Continuum emission powered by gas falling onto central black hole, At a rate of one solar mass per year, l ...
... Check for consistency: Schwarzschild radius is the radius where the “escape velocity” equals the speed of light around a black hole of mass M: RS = 2GM/c2 It relates mass and size! Accretion: Continuum emission powered by gas falling onto central black hole, At a rate of one solar mass per year, l ...
Stars, Galaxies, and the Universe
... 63310/Stars,_Galaxies,_and_the_Universe.ppt#256,1,Stars,%20Gal axies,%20and%20the%20Universe ...
... 63310/Stars,_Galaxies,_and_the_Universe.ppt#256,1,Stars,%20Gal axies,%20and%20the%20Universe ...
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.