Blowing up warped disks
... hydrocode, but in order to provide a quick proof-ofprinciple I adapted my two-dimensional code to the problem at hand. The computations presented here were performed using my FCT/LCD hydrocode (Boris & Book 1973, 1976; Icke 1991), programmed in C, running the MetroWerks CodeWarrior compiler on an Ap ...
... hydrocode, but in order to provide a quick proof-ofprinciple I adapted my two-dimensional code to the problem at hand. The computations presented here were performed using my FCT/LCD hydrocode (Boris & Book 1973, 1976; Icke 1991), programmed in C, running the MetroWerks CodeWarrior compiler on an Ap ...
Stars with T eff
... heavy elements distribution, diffusion efficiency, etc…) are taken properly into account, the difference can be reduced to about 0.8Gyr,… ...
... heavy elements distribution, diffusion efficiency, etc…) are taken properly into account, the difference can be reduced to about 0.8Gyr,… ...
FROM MOLECULAR CLOUDS TO STARS 1 Star formation and the
... parental cloud is completely disrupted and the stars appear free from circumstellar material, but still grouped in a cluster that demonstrates their common origin. Region 1b) where star formation is going on since ~ 7 Myr: on the right side of the cloud some new formed stars appear free from the clo ...
... parental cloud is completely disrupted and the stars appear free from circumstellar material, but still grouped in a cluster that demonstrates their common origin. Region 1b) where star formation is going on since ~ 7 Myr: on the right side of the cloud some new formed stars appear free from the clo ...
The Formation of High Mass Stars
... Lower surface density cases have a less concentrated gravitational potential and therefore show slower accretion per unit of free fall time than higher surface density which have a higher SFR ...
... Lower surface density cases have a less concentrated gravitational potential and therefore show slower accretion per unit of free fall time than higher surface density which have a higher SFR ...
![arXiv:1505.07406v1 [hep-ph] 27 May 2015](http://s1.studyres.com/store/data/007750137_1-1343a5635a0dda57ac4b2d01226e2ce5-300x300.png)
arXiv:1505.07406v1 [hep-ph] 27 May 2015
... interactions in asymmetric nuclear matter, the structure and stability of exotic nuclei, the reaction dynamics induced by rare isotopes, the nature and evolution of neutron stars, and the mechanism of supernova explosion [1–7]. The symmetry energy also plays an important role in some interesting iss ...
... interactions in asymmetric nuclear matter, the structure and stability of exotic nuclei, the reaction dynamics induced by rare isotopes, the nature and evolution of neutron stars, and the mechanism of supernova explosion [1–7]. The symmetry energy also plays an important role in some interesting iss ...
Wednesday, Nov 5 - Department of Physics and Astronomy
... • Event Horizon: An imaginary spherical surface with a radius = Schwarzschild radius (Rsch). • Rsch == distance from centre of an object such that, if all the M were compressed within that region, escape speed = c. ...
... • Event Horizon: An imaginary spherical surface with a radius = Schwarzschild radius (Rsch). • Rsch == distance from centre of an object such that, if all the M were compressed within that region, escape speed = c. ...
cohen_paris_v2_may2009 - Astronomy at Swarthmore College
... Magnetic massive stars have harder spectra with narrower lines and rotationally modulated variability, in general agreement with MHD simulations. Line ratio diagnostics are useful for localizing the hot plasma, and indicate that the MHD simulations predict a location that is too far from the photosp ...
... Magnetic massive stars have harder spectra with narrower lines and rotationally modulated variability, in general agreement with MHD simulations. Line ratio diagnostics are useful for localizing the hot plasma, and indicate that the MHD simulations predict a location that is too far from the photosp ...
strolympics - Chandra X
... acceleration caused by gravity. On the Earth’s surface, there’s a consistent tug from gravity. However, if you venture to other planets where gravitational forces are different or into space itself where gravity is virtually non-existent, then that object’s weight will change. Mass, however, does no ...
... acceleration caused by gravity. On the Earth’s surface, there’s a consistent tug from gravity. However, if you venture to other planets where gravitational forces are different or into space itself where gravity is virtually non-existent, then that object’s weight will change. Mass, however, does no ...
The Bigger Picture - Astronomy and Astrophysics
... • Imagine a star with a relatively cool (4000k) atmosphere. Temperature is just a measure of the average velocity of the atoms and molecules in a gas. For a relatively cool gas there are: (1) Few atomic collisions with enough energy to knock electrons up to the 1st excited state so the majority of t ...
... • Imagine a star with a relatively cool (4000k) atmosphere. Temperature is just a measure of the average velocity of the atoms and molecules in a gas. For a relatively cool gas there are: (1) Few atomic collisions with enough energy to knock electrons up to the 1st excited state so the majority of t ...
HST Paα Survey of the Galactic Center – Seeking the Missing
... clusters (Stolte et al. 2008; Paumard et al. 2006). This small sample of massive stellar clusters prevents us from making a firm conclusion about their formation mode. We do not even know whether they were formed in a single burst or were just part of a continuous star formation in the GC. We are al ...
... clusters (Stolte et al. 2008; Paumard et al. 2006). This small sample of massive stellar clusters prevents us from making a firm conclusion about their formation mode. We do not even know whether they were formed in a single burst or were just part of a continuous star formation in the GC. We are al ...
two dozen compact sources and a massive disk
... • We perform the first dynamical mass measurement using hot core line emission (410 ± 260 M), compatible with dust estimates • We analyze its structure using tools developed for infrared clusters (Qparameter of MST) • Dust masses are consistent with disks around intermediate to high-mass protostars ...
... • We perform the first dynamical mass measurement using hot core line emission (410 ± 260 M), compatible with dust estimates • We analyze its structure using tools developed for infrared clusters (Qparameter of MST) • Dust masses are consistent with disks around intermediate to high-mass protostars ...
The formation of stars and planets
... Plotting normal flux makes it look as if the source emits much more infrared radiation than optical radiation: ...
... Plotting normal flux makes it look as if the source emits much more infrared radiation than optical radiation: ...
Stars 3
... pressure but by the pressure that comes from heat energy. The carbon core ultimately reaches the 600 million degrees K needed for fusion of carbon, and the star keeps burning, developing a whole series of nuclear burning shells around an iron core. The final catastrophe for a massive star comes when ...
... pressure but by the pressure that comes from heat energy. The carbon core ultimately reaches the 600 million degrees K needed for fusion of carbon, and the star keeps burning, developing a whole series of nuclear burning shells around an iron core. The final catastrophe for a massive star comes when ...
Chemical Evolution
... populations in components predicted to be predominantly formed in mergers: stellar halo, thick disk, bulge For the Milky Way, dominantly OLD, seems to have been rather quiescent since z ~ 2; atypical in CDM? M31 more violent history? (A. Ferguson et al 2002; Brown et al 03) M33 more quiet – is ...
... populations in components predicted to be predominantly formed in mergers: stellar halo, thick disk, bulge For the Milky Way, dominantly OLD, seems to have been rather quiescent since z ~ 2; atypical in CDM? M31 more violent history? (A. Ferguson et al 2002; Brown et al 03) M33 more quiet – is ...
K2-98b: A 32 M ⊕ Neptune-Siza Planet in a 10 Day Orbit Transiting
... than 100 days (Marcy et al. 2014), determinations of masses with a precision of ∼25 % – or better – have been possible only for a few dozen Neptune-like planets1 . This is because of the small RV variations induced by such planets and the faintness of most of the Kepler host stars (V>13 mag), which ...
... than 100 days (Marcy et al. 2014), determinations of masses with a precision of ∼25 % – or better – have been possible only for a few dozen Neptune-like planets1 . This is because of the small RV variations induced by such planets and the faintness of most of the Kepler host stars (V>13 mag), which ...
Document
... • Stars experience rapid mass loss near the end of their “lives”, so the final mass can be much less than the initial mass. ...
... • Stars experience rapid mass loss near the end of their “lives”, so the final mass can be much less than the initial mass. ...
Cosmology: Black Holes, Dark Matter and Dark Energy
... VLBA Reveals Closest Pair of Supermassive Black Holes Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope have found the closest pair of supermassive black holes ever discovered in the Universe -- a duo of monsters that together are more than 150 milli ...
... VLBA Reveals Closest Pair of Supermassive Black Holes Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope have found the closest pair of supermassive black holes ever discovered in the Universe -- a duo of monsters that together are more than 150 milli ...
lec09_14oct2011
... not seen before w/IRAS. But, only the young ones (age < 3 to 6 MYr) The ages are uncertain due to models, but ~half the young wTTs lack disks (even at 0.8 to 1.5 Myr). Thus, time is NOT the only variable. How might disks ...
... not seen before w/IRAS. But, only the young ones (age < 3 to 6 MYr) The ages are uncertain due to models, but ~half the young wTTs lack disks (even at 0.8 to 1.5 Myr). Thus, time is NOT the only variable. How might disks ...
(r) and
... In this limit, each star moves in the smooth gravitational field (x,t) of the galaxy. This greatly simplifies the problem, since instead of thinking about the motion of one point in a phase space of 6N dimensions (3 spatial coordinates + 3 velocity coordinates, times N stars), we can think about ...
... In this limit, each star moves in the smooth gravitational field (x,t) of the galaxy. This greatly simplifies the problem, since instead of thinking about the motion of one point in a phase space of 6N dimensions (3 spatial coordinates + 3 velocity coordinates, times N stars), we can think about ...
Deep $ I $-band imaging of $ z=\ mathsf {5.99} $ quasar
... extended X-ray source is statistically significant. It is comprised of 7 counts, which exceeds by far the expected background flux of 0.13 counts. He estimated that the probability of observing 7 photons in a 10 arcsec2 box is 5.8×10−9. What are the chances of observing a galaxy with the given magni ...
... extended X-ray source is statistically significant. It is comprised of 7 counts, which exceeds by far the expected background flux of 0.13 counts. He estimated that the probability of observing 7 photons in a 10 arcsec2 box is 5.8×10−9. What are the chances of observing a galaxy with the given magni ...
Stars PowerPoint
... and is made up primarily of hydrogen and helium. • Astronomers learn about conditions inside the Sun by a combination of observation and theoretical models. • The Sun’s atmosphere consists of the photosphere, the chromosphere, and the corona. • The Sun has a 22-year activity cycle caused by reversal ...
... and is made up primarily of hydrogen and helium. • Astronomers learn about conditions inside the Sun by a combination of observation and theoretical models. • The Sun’s atmosphere consists of the photosphere, the chromosphere, and the corona. • The Sun has a 22-year activity cycle caused by reversal ...
Cygnus X-1
Cygnus X-1 (abbreviated Cyg X-1) is a well-known galactic X-ray source, thought to be a black hole, in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 6977229999999999999♠2.3×10−23 Wm−2 Hz−1 (7003230000000000000♠2.3×103 Jansky). Cygnus X-1 was the first X-ray source widely accepted to be a black hole and it remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 14.8 times the mass of the Sun and has been shown to be too small to be any known kind of normal star, or other likely object besides a black hole. If so, the radius of its event horizon is about 7004440000000000000♠44 km.Cygnus X-1 belongs to a high-mass X-ray binary system about 7019574266339685654♠6070 ly from the Sun that includes a blue supergiant variable star designated HDE 226868 which it orbits at about 0.2 AU, or 20% of the distance from the Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of jets, arranged perpendicular to the disk, are carrying part of the energy of the infalling material away into interstellar space.This system may belong to a stellar association called Cygnus OB3, which would mean that Cygnus X-1 is about five million years old and formed from a progenitor star that had more than 7001400000000000000♠40 solar masses. The majority of the star's mass was shed, most likely as a stellar wind. If this star had then exploded as a supernova, the resulting force would most likely have ejected the remnant from the system. Hence the star may have instead collapsed directly into a black hole.Cygnus X-1 was the subject of a friendly scientific wager between physicists Stephen Hawking and Kip Thorne in 1975, with Hawking betting that it was not a black hole. He conceded the bet in 1990 after observational data had strengthened the case that there was indeed a black hole in the system. This hypothesis has not been confirmed due to a lack of direct observation but has generally been accepted from indirect evidence.