Massive star formation in 100000 years from turbulent and
... that radiation pressure does not disrupt the flow. Although we assume the collapse is spherical far from the star, it will naturally proceed via a disk close to the star owing to the angular momentum of the accreting material; we assume this does not limit the flow of matter onto the star as otherwi ...
... that radiation pressure does not disrupt the flow. Although we assume the collapse is spherical far from the star, it will naturally proceed via a disk close to the star owing to the angular momentum of the accreting material; we assume this does not limit the flow of matter onto the star as otherwi ...
Document
... stars, gas, and dust • The remaining 90% is in some nonvisible form, called dark matter, that extends beyond the edge of the luminous material in the Galaxy • Our Galaxy’s dark matter may be a combination of MACHOs (dim, star-sized ...
... stars, gas, and dust • The remaining 90% is in some nonvisible form, called dark matter, that extends beyond the edge of the luminous material in the Galaxy • Our Galaxy’s dark matter may be a combination of MACHOs (dim, star-sized ...
Today in Astronomy 102: black hole observations, v.4
... The disk-shaped collection of matter surrounding the black hole in an AGN arises rather naturally from the influence of the black hole on stars and other material in the galactic center. Stars in a galaxy perpetually interact with each others’ gravity as well as the gravity of the galaxy at large. ...
... The disk-shaped collection of matter surrounding the black hole in an AGN arises rather naturally from the influence of the black hole on stars and other material in the galactic center. Stars in a galaxy perpetually interact with each others’ gravity as well as the gravity of the galaxy at large. ...
High Energy Emission in Extragalactic Nonblazar Sources
... (Requires low-redshift GRB to avoid attenuation by diffuse IR background) Delayed high-energy g-ray emission from superbowl burst Seven GRBs detected with EGRET either during prompt MeV burst emission or after MeV emission has decayed away (Dingus et al. 1998) Average spectrum of 4 GRBs detected ove ...
... (Requires low-redshift GRB to avoid attenuation by diffuse IR background) Delayed high-energy g-ray emission from superbowl burst Seven GRBs detected with EGRET either during prompt MeV burst emission or after MeV emission has decayed away (Dingus et al. 1998) Average spectrum of 4 GRBs detected ove ...
Lesson Plan - ScienceA2Z.com
... The bulge its self is around 20,000 x 13,000 light years in size and holds up to 1,600 stars per cubic light year (ly x ly). The Galactic Center is the rotational center of the Milky Way galaxy. It is located about 24,800 LY away from the Earth, in the direction of the constellation Sagittarius, whe ...
... The bulge its self is around 20,000 x 13,000 light years in size and holds up to 1,600 stars per cubic light year (ly x ly). The Galactic Center is the rotational center of the Milky Way galaxy. It is located about 24,800 LY away from the Earth, in the direction of the constellation Sagittarius, whe ...
Computation of the off-axis effective area of the New Hard X
... In this section we present the application of the formulae reported in Sect. 2 to the computation of the effective area of the NHXM hard X-ray telescope[2]. The NHXM optical system, as resulting from a detail optimization[11], comprises 4 identical modules with 70 mirror shells of 391 to 155 mm diam ...
... In this section we present the application of the formulae reported in Sect. 2 to the computation of the effective area of the NHXM hard X-ray telescope[2]. The NHXM optical system, as resulting from a detail optimization[11], comprises 4 identical modules with 70 mirror shells of 391 to 155 mm diam ...
Neutron stars: the densest state of condensed matter
... speculated that it "might be the remains of the original star which had exploded". John Wheeler in 1966 and Franco Pacini in 1967 proposed that a rapidly rotating neutron star with a strong dipole magnetic field could power the Crab nebula and could explain Hewish observations. ...
... speculated that it "might be the remains of the original star which had exploded". John Wheeler in 1966 and Franco Pacini in 1967 proposed that a rapidly rotating neutron star with a strong dipole magnetic field could power the Crab nebula and could explain Hewish observations. ...
A radio-pulsing white dwarf binary star
... White dwarfs are not born spinning rapidly24 , and a prior stage of accretion-driven spin-up is required. Depending upon the distance at which the accreting material coupled to the white dwarf’s magnetic field, between 0.002 M and 0.015 M of matter are required to reach PS = 1.95 min. For an accre ...
... White dwarfs are not born spinning rapidly24 , and a prior stage of accretion-driven spin-up is required. Depending upon the distance at which the accreting material coupled to the white dwarf’s magnetic field, between 0.002 M and 0.015 M of matter are required to reach PS = 1.95 min. For an accre ...
A radio pulsing white dwarf binary star
... White dwarfs are compact stars, similar in size to Earth but ∼ 200,000 times more massive1 . Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions, and the re ...
... White dwarfs are compact stars, similar in size to Earth but ∼ 200,000 times more massive1 . Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions, and the re ...
Lecture 24, The local group
... that are small now (Vc < 30 km/s) were much larger at z > 2, but suffer tidal stripping in the hierarchical merging process. The MW dSph formed in such objects with M > 109 M , so were able to build up some stellar mass and survive reionization despite their present shallow ...
... that are small now (Vc < 30 km/s) were much larger at z > 2, but suffer tidal stripping in the hierarchical merging process. The MW dSph formed in such objects with M > 109 M , so were able to build up some stellar mass and survive reionization despite their present shallow ...
Discover - Astronomy Magazine
... telescopes and detectors are helping astronomers look far beyond the solar system, where nearly all tests so far have occurred. They aim to detect how gravity behaves in the highly warped regions of space-time near superdense collapsed stars called pulsars. These extreme objects advertise their pres ...
... telescopes and detectors are helping astronomers look far beyond the solar system, where nearly all tests so far have occurred. They aim to detect how gravity behaves in the highly warped regions of space-time near superdense collapsed stars called pulsars. These extreme objects advertise their pres ...
slides
... Can we see all of the Milky way galaxy from the Earth? What is the reason we see Milky way as a luminous cloud? What is most distant object in the universe can be seen with the unaided eye? What are the dark areas in the Milky way, devoid of any stars? What are the Magellanic clouds? Are they visibl ...
... Can we see all of the Milky way galaxy from the Earth? What is the reason we see Milky way as a luminous cloud? What is most distant object in the universe can be seen with the unaided eye? What are the dark areas in the Milky way, devoid of any stars? What are the Magellanic clouds? Are they visibl ...
THE MYSTERIOUS SICKLE OBJECT IN THE CARINA NEBULA: A
... star and the X-ray source position; the nearest other star visible in the HST image is 3.8′′ offset from MJ 218. In the near-infrared HAWK-I images, we found an (insignificant) offset of 0.2′′ , and a distance of 1.9′′ to the nearest other point-source. We therefore conclude that we have a clear and ...
... star and the X-ray source position; the nearest other star visible in the HST image is 3.8′′ offset from MJ 218. In the near-infrared HAWK-I images, we found an (insignificant) offset of 0.2′′ , and a distance of 1.9′′ to the nearest other point-source. We therefore conclude that we have a clear and ...
Steps
... StePS science goal: Tracing back in cosmic time the evolution of galaxy stellar population properties as a function of galaxy stellar mass and environment, to understand the physical mechanisms that regulate galaxy formation and assembly history. ...
... StePS science goal: Tracing back in cosmic time the evolution of galaxy stellar population properties as a function of galaxy stellar mass and environment, to understand the physical mechanisms that regulate galaxy formation and assembly history. ...
Magnetars origin and progenitors with enhanced rotation'
... Magnetars origin and progenitors with enhanced rotation S.B. Popov, M.E. Prokhorov (Sternberg Astronomical Institute) ...
... Magnetars origin and progenitors with enhanced rotation S.B. Popov, M.E. Prokhorov (Sternberg Astronomical Institute) ...
galaxy evolution
... expanding superbubbles (regions of hot gas) that burst into intergalactic space creating a galactic wind. • Galactic winds consist of low-density, but extremely hot gas (10100 million K) which are detected via their x-ray emissions. • Small starburst galaxies can drive out much of their gas content, ...
... expanding superbubbles (regions of hot gas) that burst into intergalactic space creating a galactic wind. • Galactic winds consist of low-density, but extremely hot gas (10100 million K) which are detected via their x-ray emissions. • Small starburst galaxies can drive out much of their gas content, ...
A Supermassive Black Hole in the Andromeda Galaxy
... unlikely that these can be formed in collisions of low mass stars. • a 200 Million year old starburst population provides the best explanation for P3’s spectrum and the power spectrum of P3’s surface brightness fluctuations. • P3 could consist of stars that formed in the outer parts of a dense accre ...
... unlikely that these can be formed in collisions of low mass stars. • a 200 Million year old starburst population provides the best explanation for P3’s spectrum and the power spectrum of P3’s surface brightness fluctuations. • P3 could consist of stars that formed in the outer parts of a dense accre ...
Lecture 2. Thermal evolution and surface emission of neutron stars
... prototypes of a different subpopulation of NSs born with low magnetic field (< few 1011 G) and relatively long spin periods (few tenths of a second). These NSs are relatively hot, and probably not very rare. Surprisingly, we do not see objects of this type in our vicinity. In the solar neighbourhood ...
... prototypes of a different subpopulation of NSs born with low magnetic field (< few 1011 G) and relatively long spin periods (few tenths of a second). These NSs are relatively hot, and probably not very rare. Surprisingly, we do not see objects of this type in our vicinity. In the solar neighbourhood ...
18_Testbank - Lick Observatory
... Chapter 18 The Bizarre Stellar Graveyard 18.1 Multiple-Choice Questions 1) Degeneracy pressure is the source of the pressure that stops the crush of gravity in all the following except A) a brown dwarf. B) a white dwarf. C) a neutron star. D) a very massive main-sequence star. E) the central core of ...
... Chapter 18 The Bizarre Stellar Graveyard 18.1 Multiple-Choice Questions 1) Degeneracy pressure is the source of the pressure that stops the crush of gravity in all the following except A) a brown dwarf. B) a white dwarf. C) a neutron star. D) a very massive main-sequence star. E) the central core of ...
THE SHAPES OF ATOMIC LINES FROM THE SURFACES OF
... star surface could be a hot spot (produced, e.g., by magnetically channeled accretion, confined thermonuclear burning, or localized cooling gas), a belt (produced, e.g., by disk accretion near the rotational equator or rotationally confined thermonuclear burning), or a combination. Emission from a l ...
... star surface could be a hot spot (produced, e.g., by magnetically channeled accretion, confined thermonuclear burning, or localized cooling gas), a belt (produced, e.g., by disk accretion near the rotational equator or rotationally confined thermonuclear burning), or a combination. Emission from a l ...
A relativistic iron emission line from the neutron star low-mass X
... in the EPIC pn timing mode at high count rates1 . Ancillary response files were generated using the SAS task arfgen following the recommendations in the XMM-Newton SAS user guide2 for piled-up observations in timing mode whenever applicable. Response matrices were generated using the SAS task rmfgen ...
... in the EPIC pn timing mode at high count rates1 . Ancillary response files were generated using the SAS task arfgen following the recommendations in the XMM-Newton SAS user guide2 for piled-up observations in timing mode whenever applicable. Response matrices were generated using the SAS task rmfgen ...
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.