Term
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Definition
| the ______ of the wavelength of photons received at a distance gets very large as the point of emission of the photon gets deeper in a gravitational field |
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Term
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Definition
the large redshift of photons emitted near the event horizon coupled with the
long passage of time between the arrival of these photons at a distant observer due to the apparent slowing of time means events happening just outside the event horizon cannot, in practice, be “seen” by a distant observer, —hence, a "________" |
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Term
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Definition
according to Stephen Hawking, if one studies the event horizon with the
Quantum Theory one finds that the gravitation energy (and hence mass) of a black hole can be
converted into matter and anti-matter (mostly photons) with some of this material being ejected,
carrying off the mass of the hole as if the black hole had a temperature |
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Term
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Definition
For a black hole of ordinary stellar mass or larger the amount of mass
loss is negligible in the age of the Universe and may be ignored. A black hole of less than
asteroid mass could totally evaporate within the age of the Universe |
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Term
| Information Loss in Black Holes |
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Definition
| Quantum theory insists information is preserved; black holes seem to destroy it |
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Term
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Definition
| can be highly curved, but is “normal” in the sense that one can navigate and return to a given point of origin |
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Term
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Definition
| interior to event horizon space drags in one direction, just as time drags you older |
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Term
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Definition
| mass but no spin, no electrical charge. Time-like space leads to the singularity, so it cannot be avoided |
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Term
| Rotating or Kerr black hole |
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Definition
| the idealized mathematical solution of Einstein's equations developed by Kerr in which one assumes that all the mass is in the rotating singularity and that there is vacuum everywhere else. |
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Term
| Singularity in a rotating black hole |
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Definition
| shaped like a ring, surrounded by “normal ” space so that it can be avoided in principle |
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Term
| Time-like space in rotating black hole |
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Definition
the “in-going” time-like space is bounded on both sides
by an event horizon so that it does not extend down to the singularity. Inside the inner event
horizon is “normal” space surrounding the singularity. At the same place, but in the future, there
is a region of “out-going” time-like space again bounded by two event horizons leading out to a normal Universe of flat space. In the future of that Universe is another in-going time-like space |
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Term
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Definition
passing through the ring of the singularity leads to another volume of
“normal” space within the black hole surrounding the singularity, but it is not the same one that
surrounds the singularity that is first encountered when entering the black hole |
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Term
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Definition
Inside the rotating black hole the “normal” space will be one of huge
gravity and tidal forces, but they are not infinite, and one could survive in principle never emerging from the black hole, but also never hitting the singularity |
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Term
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Definition
in a real Universe matter and energy falling into a black hole will gain energy (blue
shift) and that energy will probably alter the “vacuum” Kerr solution, so no extra Universes are accessible. |
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Term
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Definition
| look for binary system where X-rays are produced in accretion disk before matter disappears down the black hole and Kepler’s law helps to determine mass greater than maximum mass of neutron star |
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Term
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Definition
First candidate black hole in a binary star system. Object of 10 M emits X-rays and orbits un-evolved star of 30 M. Astronomers worried that the 10 M object is itself a 9 M
star transferring mass to a 1 M neutron star. The 9 M star could be lost in glare of 30 M star.
This was ruled out by careful observations |
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Term
| Black hole candidates with low mass companion stars |
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Definition
for these systems the “unseen” X-ray
emitting star is more massive than the un-evolved companion. No third ordinary star could remain unseen |
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Term
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Definition
| contains a 4 million solar mass black hole as determined by orbits of stars near the center |
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Term
| Galaxy/Black Hole connection |
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Definition
The velocities of stars that respond to the bulge mass of a galaxy are correlated with the mass of the central supermassive black hole despite the fact that they are presently much too far from the black hole to sense its gravity. The bulge mass is always about 800 times the black hole mass. This suggests that the processes that cause the development of whole galaxies are nevertheless closely linked to the growth of the black hole when both first
formed |
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Term
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Definition
| flashes of gamma-ray energy detected by satellites about once per day lasting about 10 to 30 seconds |
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Term
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Definition
| the gamma-ray bursts occur randomly all over the sky, so they are not associated with our Galaxy |
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Term
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Definition
discovered only in 1997, these allow gamma-ray bursts to be associated
with other phenomena. They are in galaxies at cosmological distances |
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Term
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Definition
| fading radiation in radio, optical, and x-ray lasting for weeks or months after main burst, collision of ejected material with matter surrounding the star |
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Term
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Definition
Gamma-ray burst in March of 2003 proved that at least this burst was associated
with a Type Ic supernova. Several others have been associated with supernovae since then, all Type Ic |
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Term
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Definition
was 12.2 billion light years away. It was equivalent to 9000 supernovae, the
brightest optical event ever recorded. |
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Term
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Definition
is the most distant object for which a spectrum has been obtained, 13.1 billion light
years away, when the Universe was only 600 million years old. |
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Term
| Gamma-ray bursts and cosmology |
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Definition
| gamma-ray bursts are so bright they might be the first objects observable as stars first began to form and die at the end of the “Dark Ages” after the Big Bang cooled off |
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