University of Groningen Colliding winds in Wolf-Rayet
... are yet to be determined. When unexpectedly-bright radio emission was observed from a few Wolf-Rayet stars in the 70-80s, the exciting interpretation was that a compact, unseen companion was the origin, accreting matter from the WR star; that neutron stars or even black holes had been detected! Twen ...
... are yet to be determined. When unexpectedly-bright radio emission was observed from a few Wolf-Rayet stars in the 70-80s, the exciting interpretation was that a compact, unseen companion was the origin, accreting matter from the WR star; that neutron stars or even black holes had been detected! Twen ...
Black Hole Accretion
... Black Hole: A remarkable prediction of Einstein’s General Theory of Relativity – represents the victory of gravity ...
... Black Hole: A remarkable prediction of Einstein’s General Theory of Relativity – represents the victory of gravity ...
Massive close binaries, observational characteristics - UvA-DARE
... from mass-exchange binaries in which the original primary star has exploded as a supemova. Many of them might well have an unseen compact companion star (see especially also Stone, 1991). Alternatively if large asymmetries in the SN mass ejection occur (see next section), it is also possible that a ...
... from mass-exchange binaries in which the original primary star has exploded as a supemova. Many of them might well have an unseen compact companion star (see especially also Stone, 1991). Alternatively if large asymmetries in the SN mass ejection occur (see next section), it is also possible that a ...
Review: How does a star`s mass determine its life story?
... about same size as Earth. Higher-mass white dwarfs are smaller. ...
... about same size as Earth. Higher-mass white dwarfs are smaller. ...
Explores Angular Size - Chandra X
... how big something is in kilometers, instead of how big it appears to be in angular measure. To get this information, all we need to know is how far away the object is from us. The moon is 324,000 kilometers away, and Venus is about 40 million kilometers away from Earth at its closest distance. The f ...
... how big something is in kilometers, instead of how big it appears to be in angular measure. To get this information, all we need to know is how far away the object is from us. The moon is 324,000 kilometers away, and Venus is about 40 million kilometers away from Earth at its closest distance. The f ...
Gamma Ray Bursts
... Scientists think it could come from the collisions of two very dense objects, such as neutron stars in a binary. Also, some think, they could be from the same process as the long GRB but were not directly along the axis of the emission, i.e. not seeing it face on. ...
... Scientists think it could come from the collisions of two very dense objects, such as neutron stars in a binary. Also, some think, they could be from the same process as the long GRB but were not directly along the axis of the emission, i.e. not seeing it face on. ...
Properties of long gamma-ray bursts from massive compact binaries
... We use the binary population of Church et al. [7], within which we searched for double blackhole binaries that satisfy the criterion of Levan et al. [6]. In summary, this requires that the binary be tight enough that, assuming tidal locking, the core is spun up sufficiently that its outer parts form ...
... We use the binary population of Church et al. [7], within which we searched for double blackhole binaries that satisfy the criterion of Levan et al. [6]. In summary, this requires that the binary be tight enough that, assuming tidal locking, the core is spun up sufficiently that its outer parts form ...
Document
... These modes are characterized by quantum numbers (k,l,m) similar to atomic orbitals Spherical gravitational potential Spherical electrostatic potential l determines the number of borders between hot and cool zones on the surface m is the number of borders that pass through the pole of the rotation ...
... These modes are characterized by quantum numbers (k,l,m) similar to atomic orbitals Spherical gravitational potential Spherical electrostatic potential l determines the number of borders between hot and cool zones on the surface m is the number of borders that pass through the pole of the rotation ...
CV - iucaa
... of Fermi GRBs with the Palomar Transient Factory. ArXiv e-prints, 2015. • Tomsick, J. A., Bellm, E., Fuerst, F., et al. NuSTAR Observations of X-Ray Binaries. ArXiv e-prints, 2015. • Younes, G., Kouveliotou, C., Grefenstette, B. W., et al. Simultaneous NuSTAR/Chandra observations of the Bursting Pul ...
... of Fermi GRBs with the Palomar Transient Factory. ArXiv e-prints, 2015. • Tomsick, J. A., Bellm, E., Fuerst, F., et al. NuSTAR Observations of X-Ray Binaries. ArXiv e-prints, 2015. • Younes, G., Kouveliotou, C., Grefenstette, B. W., et al. Simultaneous NuSTAR/Chandra observations of the Bursting Pul ...
Galaxies
... Mass of the Galaxy • The orbit of clusters can be used to estimate the mass of the galaxy. • This is the same method used for planets and binary stars. • The Milky Way galaxy has a mass of 1 trillion (1012) M. • Most of the mass is not at the center. ...
... Mass of the Galaxy • The orbit of clusters can be used to estimate the mass of the galaxy. • This is the same method used for planets and binary stars. • The Milky Way galaxy has a mass of 1 trillion (1012) M. • Most of the mass is not at the center. ...
the 82nd arthur h. compton lecture series
... seen as absorption lines in the spectrum that give us insights on its composition. 3. If matter is hot enough it can emit it’s own radiation and produce emission lines that also tell us about its composition. ...
... seen as absorption lines in the spectrum that give us insights on its composition. 3. If matter is hot enough it can emit it’s own radiation and produce emission lines that also tell us about its composition. ...
Spectroscopy PPT
... Most of what is known about stars comes from spectroscopy (or the study of spectra). Spectra (rainbows of diffracted light) can come from a (hot) glowing solid, a glowing liquid or a glowing gas (star). ...
... Most of what is known about stars comes from spectroscopy (or the study of spectra). Spectra (rainbows of diffracted light) can come from a (hot) glowing solid, a glowing liquid or a glowing gas (star). ...
2.3 Peculiar galaxies
... centre of the galaxy, it can have an influence on huge regions much bigger than the galaxy itself. AGN properties : nuclear jets. Measurements in the central regions of radio galaxies show that such jets can continue to be seen down to very tiny scales. Repeated measurements on the very smallest sca ...
... centre of the galaxy, it can have an influence on huge regions much bigger than the galaxy itself. AGN properties : nuclear jets. Measurements in the central regions of radio galaxies show that such jets can continue to be seen down to very tiny scales. Repeated measurements on the very smallest sca ...
PowerPoint - Mark Kidger
... What is a Quasar? • Quasar is a contraction of Quasi-Stellar Object. • They are objects that look like faint, blue stars, but are really incredibly distant. • They are the extremely luminous nuclei of distant galaxies. • Quasars are powered by supermassive black holes that are practicing cannibalis ...
... What is a Quasar? • Quasar is a contraction of Quasi-Stellar Object. • They are objects that look like faint, blue stars, but are really incredibly distant. • They are the extremely luminous nuclei of distant galaxies. • Quasars are powered by supermassive black holes that are practicing cannibalis ...
HI in Local Group Dwarf Galaxies
... • All of the SDSS dwarfs except Leo T are devoid of gas to our detection limits, and these upper limits are lower than the HI mass of any known dwarf which has HI. • Dwarf galaxies at smaller galactocentric distances have less HI on average than those at larger distances. • The HI -distance trend su ...
... • All of the SDSS dwarfs except Leo T are devoid of gas to our detection limits, and these upper limits are lower than the HI mass of any known dwarf which has HI. • Dwarf galaxies at smaller galactocentric distances have less HI on average than those at larger distances. • The HI -distance trend su ...
lecture27
... What does careful study of our Milky Way Galaxy tell us about galaxy formation? • The Milky Way’s halo stars are very old and their orbits have random orientations, suggesting that they did indeed form before the protogalactic cloud collapsed into a disk. The low abundances of heavy elements in halo ...
... What does careful study of our Milky Way Galaxy tell us about galaxy formation? • The Milky Way’s halo stars are very old and their orbits have random orientations, suggesting that they did indeed form before the protogalactic cloud collapsed into a disk. The low abundances of heavy elements in halo ...
the chromospheres of classical cepheids. 111. a search for transition
... less steadily until the next cycle again excites it. At the phase of strongest emission, the flux is comparable to nonvariable stars of similar luminosity and temperature, but at other phases and averaged over the cycle the chromospheric activity is significantly less than in the nonvariable stars. ...
... less steadily until the next cycle again excites it. At the phase of strongest emission, the flux is comparable to nonvariable stars of similar luminosity and temperature, but at other phases and averaged over the cycle the chromospheric activity is significantly less than in the nonvariable stars. ...
Reconnaissance of the TRAPPIST-1 exoplanet system in the Lyman
... 2017), this might be an indication of a similarly variable chromosphere. Alternatively, and given that the Ly-α line is stable over time outside of the above ranges (Fig. 3), this might hint at the presence of hydrogen exospheres around the two inner planets. The measured variations are too large to ...
... 2017), this might be an indication of a similarly variable chromosphere. Alternatively, and given that the Ly-α line is stable over time outside of the above ranges (Fig. 3), this might hint at the presence of hydrogen exospheres around the two inner planets. The measured variations are too large to ...
Astronomy
... Directions: Answer the following questions with the most correct answers. TRUE/FALSE: 1. _____ Hubble classified galaxies 2. _____ There are three main classifications of galaxies 3. _____ Elliptical galaxies have little or no star formation 4. _____ Elliptical galaxies have little or no rotation 5. ...
... Directions: Answer the following questions with the most correct answers. TRUE/FALSE: 1. _____ Hubble classified galaxies 2. _____ There are three main classifications of galaxies 3. _____ Elliptical galaxies have little or no star formation 4. _____ Elliptical galaxies have little or no rotation 5. ...
What is a white dwarf?
... • Adding mass to a white dwarf increases its gravity, forcing electrons into a smaller space • In order to avoid being in the same state in the same place some of the electrons need to move faster. That increases the temperature, but not the pressure degeneracy pressure doesn't depend on tempe ...
... • Adding mass to a white dwarf increases its gravity, forcing electrons into a smaller space • In order to avoid being in the same state in the same place some of the electrons need to move faster. That increases the temperature, but not the pressure degeneracy pressure doesn't depend on tempe ...
Nuclear Synthesis
... • star clusters and how they are used to study star aging • steps leading from gas cloud to main sequence star • steps leading from Red giant to supernova (or white dwarf to SN) • difference between white dwarf, neutron star, black hole • four forces and examples from star’s lifecycle: gravity ...
... • star clusters and how they are used to study star aging • steps leading from gas cloud to main sequence star • steps leading from Red giant to supernova (or white dwarf to SN) • difference between white dwarf, neutron star, black hole • four forces and examples from star’s lifecycle: gravity ...
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.