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CH 22 HW
Detecting a black hole is a challenging endeavor for astronomers. Why is it so difficult for astronomers to observationally detect black holes?
Black holes reside in a region of space that is dark, empty, and undetectable by any astronomical instruments. |
Black holes reside at the centers of bright stars, whose light outshines the light emitted from the black holes. |
Black holes have an escape speed that is greater than the speed of light. |
Black holes emit radiation only once every few thousand years. |
The most rapidly "blinking" pulsars are those that
are oldest. |
are hottest. |
spin fastest. |
are most massive. |
The X-ray emission from a neutron star in a binary system comes mainly from
the neutron star's magnetic field. |
the surface of the companion star. |
the hot surface of the neutron star itself. |
heated material in an accretion disk around the neutron star. |
Gamma-ray bursts are observed to occur
near pulsars. |
mainly near the Sun. |
throughout the Milky Way Galaxy. |
approximately uniformly over the entire sky. |
The properties of neutron stars help explain their relationship to pulsars. Which of the following is (are) important when explaining how a pulsar generates the radiation we detect?
Neutron stars can rotate extremely rapidly, as quickly as 30 times a second or more. |
The extremely high temperatures produce gamma rays from fusion in the neutron star. |
The magnetic field lines in a neutron star are squeezed close together, creating an extremely intense magnetic field. |
A neutron star is a dense sphere composed almost entirely of compressed neutrons with a mass one to three times that of the Sun. |
If the Sun were magically to turn into a black hole of the same mass,
Earth would fly off into space. |
Earth's orbit would remain unchanged. |
Earth would be torn apart. |
Earth would start to spiral inward. |
Neutron stars and pulsars are associated with
the collapse and supernova explosion of massive stars |
the end stage of low-mass star evolution |
the birth of low-mass stars |
the birth of massive stars |
Black holes...
are the end states of stars like our Sun |
suck up everything in their vicinity, so orbits around them are not possible |
prevent anything inside the event horizon from escaping |
If there is a black hole in a binary system with a blue supergiant star, the X-ray radiation we may observe would be due to the
supergiant star |
accretion disk of material falling into the black hole |
radiation from inside the event horizon of the black hole |
The best evidence for supermassive black holes in the centers of galaxies is
the absence of stars there. |
unknown visible and X-ray spectral lines. |
gravitational redshift of radiation emitted from near the center. |
rapid gas motion and intense energy emission. |
A neutron star's immense gravitational attraction is due primarily to its small radius and
large mass. |
rapid rotation rate. |
high temperature. |
strong magnetic field. |
NoteStudied by 10 peopleNoteStudied by 41 peopleNoteStudied by 173 peopleNoteStudied by 11 peopleNoteStudied by 4 peopleNoteStudied by 4 people