Quasars are small because they are powered by supermassive black holes at the centers of galaxies. The intense energy emitted by the accretion of matter onto the black hole creates a very compact and luminous source in the center of a galaxy.
Astronomers determine the size of quasars by analyzing the variability of their light. Quasars show rapid and dramatic changes in brightness over short periods, indicating that they must be very compact, likely smaller than our own solar system. By studying the time scales of these changes, astronomers can estimate the size of quasars.
Quasars typically have large redshifts, which indicate that they are moving away from us at high speeds. This redshift is due to the expansion of the universe and can help astronomers determine the distance and age of quasars.
Typically, a galaxy may contain one or a few quasars. Quasars are incredibly luminous objects powered by supermassive black holes at the centers of galaxies. They are rare and only occur under specific conditions, so it is not common for a galaxy to have multiple quasars.
Quasars are highly luminous due to the accretion of mass onto supermassive black holes at their centers. Since their luminosity comes from a small region near the black hole, they must be compact in size. Observations of rapid variability in their light output further support the idea that quasars are small objects, as these changes happen on timescales that would be consistent with a compact source.
Not the existence of quasars, but the fact that all quasars are distant from us. The best explanation for what we observe when we see quasars is that they are super-massive black holes in early galaxies, burning up solar "fuel" so rapidly that they eventually run out. We do not observe any quasars near to us, so the conditions that allowed quasars to form must have existed only several billion years ago. If our Universe has not changed its basic structure and density over the last 15 billion years or so, then the conditions that would allow quasars would allow them to exist at any time over that span. This would mean that there should be just as many quasars close to us as there are far from us. But we just don't see that. As is the case with many of the things we see, this is easy to explain via Big Bang Cosmology but almost impossible to explain with any alternative.
Astronomers determine the size of quasars by analyzing the variability of their light. Quasars show rapid and dramatic changes in brightness over short periods, indicating that they must be very compact, likely smaller than our own solar system. By studying the time scales of these changes, astronomers can estimate the size of quasars.
Quasars typically have large redshifts, which indicate that they are moving away from us at high speeds. This redshift is due to the expansion of the universe and can help astronomers determine the distance and age of quasars.
Typically, a galaxy may contain one or a few quasars. Quasars are incredibly luminous objects powered by supermassive black holes at the centers of galaxies. They are rare and only occur under specific conditions, so it is not common for a galaxy to have multiple quasars.
Quasars are highly luminous due to the accretion of mass onto supermassive black holes at their centers. Since their luminosity comes from a small region near the black hole, they must be compact in size. Observations of rapid variability in their light output further support the idea that quasars are small objects, as these changes happen on timescales that would be consistent with a compact source.
quasars
Not the existence of quasars, but the fact that all quasars are distant from us. The best explanation for what we observe when we see quasars is that they are super-massive black holes in early galaxies, burning up solar "fuel" so rapidly that they eventually run out. We do not observe any quasars near to us, so the conditions that allowed quasars to form must have existed only several billion years ago. If our Universe has not changed its basic structure and density over the last 15 billion years or so, then the conditions that would allow quasars would allow them to exist at any time over that span. This would mean that there should be just as many quasars close to us as there are far from us. But we just don't see that. As is the case with many of the things we see, this is easy to explain via Big Bang Cosmology but almost impossible to explain with any alternative.
Quasars are thought to be distant super-massive black holes.
The first quasars were discovered in the 1950's
Yes. Quasars are the size of the solar system.
Quasars do not have galaxies in them, quasars are at the hearts of galaxies. All quasars are located in galaxies, as a quasar involves massive amounts of material falling into a supermassiv black hole. Neither of these can be found outside of a galaxy.
Quasars are not gone; they are still observed in the universe. Quasars are powered by accretion of material onto supermassive black holes at the centers of galaxies, which can make them appear as some of the brightest and most powerful objects in the universe. However, the number of observed quasars may be influenced by factors such as the current stage of galaxy evolution or observational limitations.
pulsar and quasars