Tests of Alternative Theories of Gravity
... Quantization of gravity & unification with other forces [strings] predict the existence of PARTNERS to graviton Useful to contrast their predictions with G.R.: – What theoretical information can we extract from experimental data? ...
... Quantization of gravity & unification with other forces [strings] predict the existence of PARTNERS to graviton Useful to contrast their predictions with G.R.: – What theoretical information can we extract from experimental data? ...
Lecture 2. Thermal evolution and surface emission of
... No accreted envelopes, Envelopes + Fields Thick lines – no envelope different magnetic fields. Envelopes can be related to the fact that we see a subpopulation of hot NS Thick lines – non-magnetic in CCOs with relatively long initial spin periods and low magnetic field, but do not observed represent ...
... No accreted envelopes, Envelopes + Fields Thick lines – no envelope different magnetic fields. Envelopes can be related to the fact that we see a subpopulation of hot NS Thick lines – non-magnetic in CCOs with relatively long initial spin periods and low magnetic field, but do not observed represent ...
Evolution and nucleosynthesis of extremely metal
... applying this further dilution factor our model self-consistently reproduces the observed C, N, and O abundances within a factor of 4 for N and 3 for O (observational error bars are ∼ a factor of 2) with Fe increasing by only 20%. However, it produces 59 times more Sr and at least 260 times more Ba ...
... applying this further dilution factor our model self-consistently reproduces the observed C, N, and O abundances within a factor of 4 for N and 3 for O (observational error bars are ∼ a factor of 2) with Fe increasing by only 20%. However, it produces 59 times more Sr and at least 260 times more Ba ...
Using a distant X-ray source to detect small Transneptunian Objects
... A Taiwanese astronomy team has used an unusual technique to detect very small TNOs. They used measurements from the satellite ROSSI X-ray Timing Explorer of the brightest X-ray object in the sky, Scorpius X-1, which is a pulsar (a neutron star). The team used 90 hours of data obtained between 1996 a ...
... A Taiwanese astronomy team has used an unusual technique to detect very small TNOs. They used measurements from the satellite ROSSI X-ray Timing Explorer of the brightest X-ray object in the sky, Scorpius X-1, which is a pulsar (a neutron star). The team used 90 hours of data obtained between 1996 a ...
University of Groningen Weak Interactions in Neutron Stars van
... The standard coolirig scenario of lFri79] is based upon a nonrelativistic quasiparticle approxiniation and the use of the one-pion exchange potential. For a low neutrino energy (1 MeV) the two-body neutrino emission processes are directly related to the nucleon-nucleon scattering according to the Lo ...
... The standard coolirig scenario of lFri79] is based upon a nonrelativistic quasiparticle approxiniation and the use of the one-pion exchange potential. For a low neutrino energy (1 MeV) the two-body neutrino emission processes are directly related to the nucleon-nucleon scattering according to the Lo ...
X-ray Polarimetry - XMM-Newton Science Operations Centre
... signal response function. •Use measured response pulses to do optimal filtering deconvolution (Wiener filtering) to recover input. •Improves signal to noise compared to unfiltered deconvolution. ...
... signal response function. •Use measured response pulses to do optimal filtering deconvolution (Wiener filtering) to recover input. •Improves signal to noise compared to unfiltered deconvolution. ...
Death of the Stars
... Finally, the star becomes about 30kms in diameter, and about 1,000,000 degrees at the surfaces. In the 1930s, the existence of neutron stars were proposed, however as they were very small, they were only (it was) observed after the HST. ...
... Finally, the star becomes about 30kms in diameter, and about 1,000,000 degrees at the surfaces. In the 1930s, the existence of neutron stars were proposed, however as they were very small, they were only (it was) observed after the HST. ...
Nuclear Synthesis
... • difference between white dwarf, neutron star, black hole • four forces and examples from star’s lifecycle: gravity pulls material in raising temperature allows fusion to start. Electric force resists gravity and causes light to be emitted. Strong nuclear force causes fusion to release energy. We ...
... • difference between white dwarf, neutron star, black hole • four forces and examples from star’s lifecycle: gravity pulls material in raising temperature allows fusion to start. Electric force resists gravity and causes light to be emitted. Strong nuclear force causes fusion to release energy. We ...
X-Ray Binaries
... Formation Scenarios • the present size of many XRB’s (∼ 0.1 − 10 R¯) is much smaller than the size of a blue/red supergiant, the progenitor of the compact object → require drastic shrinkage of orbit • common-envelope evolution ...
... Formation Scenarios • the present size of many XRB’s (∼ 0.1 − 10 R¯) is much smaller than the size of a blue/red supergiant, the progenitor of the compact object → require drastic shrinkage of orbit • common-envelope evolution ...
Ch12&13 Life and Death of Stars
... Iron core of massive star reaches white dwarf limit and collapses into a neutron star, causing explosion ...
... Iron core of massive star reaches white dwarf limit and collapses into a neutron star, causing explosion ...
Pp 263-266 - Gravity From The Ground Up
... neutron stars to form in the first place. The maximum mass is a property of nuclear physics and general relativity. The Chandrasekhar mass depends on Newtonian gravity and atomic physics. We could imagine a Universe in which the nuclear repulsive core was smaller, so that neutron stars were denser a ...
... neutron stars to form in the first place. The maximum mass is a property of nuclear physics and general relativity. The Chandrasekhar mass depends on Newtonian gravity and atomic physics. We could imagine a Universe in which the nuclear repulsive core was smaller, so that neutron stars were denser a ...
Lecture19
... It would surface again on the opposite side of the planet, and fall again. Again and again it would fall until it settled at the center of the earth. ...
... It would surface again on the opposite side of the planet, and fall again. Again and again it would fall until it settled at the center of the earth. ...
Fatal Fling Solar Plasma at a Slow Pace - Max-Planck
... Max Planck scientists discover a young neutron star with an unusually restless rotation Pulsars are exceptional cosmic lighthouses. Compact neutron stars rotate several times a second about their own axes, making them appear to flash. In an international cooperative study, researchers at the Max Pla ...
... Max Planck scientists discover a young neutron star with an unusually restless rotation Pulsars are exceptional cosmic lighthouses. Compact neutron stars rotate several times a second about their own axes, making them appear to flash. In an international cooperative study, researchers at the Max Pla ...
LISTENING FOR THE HUM OF NEUTRON STARS IN THE CENTER
... Gravitational waves interact only very weakly with matter. Therefore, we need very sensitive detectors and an effective data analysis method to dig out the signal from the noise. For this, we need an accurate model of the signals we want to find. They can be described by a handful of parameters: the ...
... Gravitational waves interact only very weakly with matter. Therefore, we need very sensitive detectors and an effective data analysis method to dig out the signal from the noise. For this, we need an accurate model of the signals we want to find. They can be described by a handful of parameters: the ...
Accretion Disk
... ejected in all directions (but preferentially in the plane of the orbit). • The system’s semi-major axis will shrink (by a factor of ~ 100) and the orbit will circularize on a dynamical timescale. Eventually, the star reaches the denser layers of the giant, and mass ejection becomes harder. The mas ...
... ejected in all directions (but preferentially in the plane of the orbit). • The system’s semi-major axis will shrink (by a factor of ~ 100) and the orbit will circularize on a dynamical timescale. Eventually, the star reaches the denser layers of the giant, and mass ejection becomes harder. The mas ...
nebula - Harding University
... Some astronomers proposed that the pulsating signal arose from the rotation of a star. Although most astronomers at that time believed that the majority of “dead” stars were white dwarfs, the discovery of very rapid pulsars, like the one in the Crab Nebula (period of 0.033 seconds), indicated that a ...
... Some astronomers proposed that the pulsating signal arose from the rotation of a star. Although most astronomers at that time believed that the majority of “dead” stars were white dwarfs, the discovery of very rapid pulsars, like the one in the Crab Nebula (period of 0.033 seconds), indicated that a ...
Talk, ppt
... Bow shocks are observed on a wide variety of astrophysical scales, from planetary magnetospheres to galaxy clusters. Some of the most spectacular bow shock nebulae are associated with neutron stars. A visually example is the Guitar Nebula: ...
... Bow shocks are observed on a wide variety of astrophysical scales, from planetary magnetospheres to galaxy clusters. Some of the most spectacular bow shock nebulae are associated with neutron stars. A visually example is the Guitar Nebula: ...
R 2
... How irradiation helps in X-ray binaries •The orbital period increases as observed • The mass loss rate is larger • The number ratio LMXB/MSPs is more reasonable • The system evolves through alternated high Mdot phases and detached phases which may help in explaining why radio MSPs do not accrete to ...
... How irradiation helps in X-ray binaries •The orbital period increases as observed • The mass loss rate is larger • The number ratio LMXB/MSPs is more reasonable • The system evolves through alternated high Mdot phases and detached phases which may help in explaining why radio MSPs do not accrete to ...
ppt - 2006 Mitchell Symposium
... The magnetic field generated by the MRI must be included in any selfconsistent collapse calculation - but hard, numerical resolution. Relevant magnetohydrodynamics - large magnetic fields generated internally, primarily toroidal, not the product of twisting of external field lines ...
... The magnetic field generated by the MRI must be included in any selfconsistent collapse calculation - but hard, numerical resolution. Relevant magnetohydrodynamics - large magnetic fields generated internally, primarily toroidal, not the product of twisting of external field lines ...
essay - Caltech Astronomy
... Several times, owing to my longer experience, I was able to see or discern that a discovery was already present in our data. I made a point to let the student make the discovery on his or her own timescales, sometimes many months later. There is some risk of being scooped but in my view there is not ...
... Several times, owing to my longer experience, I was able to see or discern that a discovery was already present in our data. I made a point to let the student make the discovery on his or her own timescales, sometimes many months later. There is some risk of being scooped but in my view there is not ...
Observational properties of stars
... night sky, and comparable to the brightness of a quarter or gibbous phase moon (though concentrated into a point). The object was visible in the sky for 2 years. A supernova remnant is associated with this event, and currently it is thought to have been a Type Ia. SN1054 – (July 4) in Taurus, observ ...
... night sky, and comparable to the brightness of a quarter or gibbous phase moon (though concentrated into a point). The object was visible in the sky for 2 years. A supernova remnant is associated with this event, and currently it is thought to have been a Type Ia. SN1054 – (July 4) in Taurus, observ ...
Pulsar
A pulsar (short for pulsating radio star) is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. This radiation can only be observed when the beam of emission is pointing toward Earth, much the way a lighthouse can only be seen when the light is pointed in the direction of an observer, and is responsible for the pulsed appearance of emission. Neutron stars are very dense, and have short, regular rotational periods. This produces a very precise interval between pulses that range roughly from milliseconds to seconds for an individual pulsar. Pulsars are believed to be one of the candidates of high and ultra-high energy astroparticles (see also Centrifugal mechanism of acceleration).The precise periods of pulsars make them useful tools. Observations of a pulsar in a binary neutron star system were used to indirectly confirm the existence of gravitational radiation. The first extrasolar planets were discovered around a pulsar, PSR B1257+12. Certain types of pulsars rival atomic clocks in their accuracy in keeping time.