Quasars, Redshifts and Controversies
Quasars, Redshifts and Controversies is a 1987 book by Halton Arp, an astronomer famous for his work on anomalous redshifts.
List of quasars
Pages in category "Quasars"
The following 2 pages are in this category, out of 2 total.
In this view quasars are special Active Galactic Nuclei that have their jets lined up with our line of sight. So we are looking straight down the jet and it seems extraordinarily bright.
The first quasars were discovered in the early 1960s, when measured their very strong radio emissions.
Quasars
Wow!
Quasars give off more energy than 100 normal galaxies combined.
quasars turning on in a finite time
dust envelopes around quasars dispersing
galaxies forming
an effect of opacity in the IGM or intervening galaxies ...
Astronomers believe that the early Universe was dust free, which means that the first quasars must also be devoid of dust, however no one had observed such pristine examples until now.
Quasars
Quasars comprise the most luminous subclass of AGNs, with nuclear magnitudes MB h0. A small minority (5-10%) of these sources are the strong radio sources that originally defined the quasar class.
Quasars
In the late 1950s and early 1960s, a new class of radio source objects was first catalogued. These sources of radio waves were soon matched to what appeared to be very dim stars in the visual band (2).
Quasars as Probes of the Distant Universe
Absorption of their light by intervening objects ...
Quasars, or quasi-stellar objects, were first discovered as starlike radio sources with unknown broad spectral lines.
Quasars
Quasars appear to radiate with the luminosity of hundreds of galaxies, but each quasar is smaller than a typical galaxy by a factor of nearly a million.
Quasars - Even the brightest star, at a luminosity of 40 million suns, it is still not the brightest object in the universe. This honor belongs to the Quasars, of which several hundred are currently known.
Quasars
Quasars were originally thought to be stars with very strange spectra. If you look at a quasar you usually see a point of light - just like what you see when you look at a normal star in our galaxy.
[edit] Quasars
In the 1950s, some strong radio sources were found to be associated with very dim objects that seemed to be very blue. These were named Quasi-stellar radio sources, or quasars.
type II quasars
a quasar enshrouded in gas and dust that emits very little visibile light, however, is easily seen in the infrared and x-ray region of the electromagnetic spectrum
type II supernova ...
Quasars are a subset of the active galaxy class, which is probably powered by a super massive black hole at the center of the galaxy.
Quasars tend to be found at great distances from us; there are no nearby quasars. When we look at quasars, we see them as they were billions of years ago.
Quasars are a good candidate source because they are highly efficient at converting mass to energy, and emit a great deal of light above the threshold for ionizing hydrogen.
Quasars were first detected as unresolved sources in surveys conducted during the 1950s by radio astronomers in Cambridge, Eng.
Quasars are very compact objects - the word "quasar" and the acronym "QSO" are short for "quasi-stellar radio source" and "Quasi-stellar object" respectively, due to their 'star-like' appearance.
Quasars
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The Universe ...
quasars Originally, a distant, highly luminous object that looks like a star. Strong evidence now exists that a quasar is produced by gas falling into a supermassive black hole in the center of a galaxy. [More Info: Field Guide] ...
Quasars are perhaps the most luminous object known; some (including 3 C 273) are known to have absolute magnitudes as great as -27.
Burnham (p. 2101) gives an identification chart, as well as a detailed discussion on the phenomenon of quasars.
Quasars exhibit very bright emission features relative to a low intensity continuum in their spectra. Indeed it was only through careful analysis of the spectra of quasars that astronomers realised they were not just faint stars.
Quasars are predicted to only be possible in the early stages of a dynamic cosmos by the Big Bang theory, and observational evidence supports this, as quasar populations become denser the further away one looks. (more needed)
Olbers' Paradox ...
[8.4] QUASARS
[9.0] Cosmology & The Big Bang
[9.1] THE ORIGINS OF COSMOLOGY / THE EXPANDING UNIVERSE ...
RADIO STAR
Quasars were called "radio stars" in the early 1960's when they were first detected, because they emit large amounts of radiation, including radio waves.
Distance to quasars ( Here is one of the most famous quasars, 3C273. Courtesy NOAO/NSF.)
1024
Size of a typical cluster of galaxies ( One example of galaxy cluster, near 3C324. Courtesy STScI.) ...
quasars (High Energy Astrophysics Dictionary- GSFC) A specific type of quasi-stellar source. A stellar-appearing object of very large redshift that is a strong source of radio waves; presumed to be extragalactic and highly luminous.
The theory that quasars are not at great distances but relatively nearby.
Long Period Variable
A variable star with a period ranging from 100 days to over 400 days.
Quasars were discovered as the visible counterparts of certain discrete celestial sources of radio waves (see radio astronomy). Similar starlike objects that do not emit radio waves were subsequently discovered and named quasi-stellar objects (QSOs).
AGN are found at the heart of active galaxies, including quasars, Seyfert galaxies, blazars, and radio galaxies. In addition to their great energy output, they can be highly variable.
For many years there was only indirect evidence of supermassive black holes: the existence of quasars.
The most powerful active galaxies are quasars. They are among the brightest and most distant objects in the universe. A quasar may emit more energy than an entire galaxy of stars from a region no bigger than our own solar system.
Young objects such as quasars were only observed at the very edges of the universe, indicating that such objects only existed in times long past, whereas the Steady State predicted that young galaxies should be scattered all over the universe, ...
Infrared observations reveal quasars to be associated with active host galaxies (McLeod and Rieke 1994, 1995), despite initial claims by J. Bahcall that Hubble images revealed many quasars to be "naked" (Kaiser 1995, Travis 1995).
Quasars and other active galaxies were also found to be strong infrared emitters. All of this new information came from near-infrared observations which could be made from the ground.
Quasars, ultra-luminous galaxies thought to be powered by supermassive black holes, are found throughout the ancient universe. Usually seen as point-like objects, telescopes such as Hubble can resolve the disk of surrounding material.
Some quasars (quasi-stellar objects, or QSOs) are strong radio sources. Radio-emitting quasars were the first to be discovered.
An example was the early belief that all quasars are radio sources, when the principal method used to discover quasars was to look for radio sources and then to find out whether they had other properties associated with quasars.
Definition: microquasar: Microquasars are stellar mass black holes, that display characteristics of the supermassive black holes found at the centers of some galaxies. For instance, they have radio jets - something not every black hole has.
The word "quasar" is derived from quasi-stellar radio source, because this type of object was first identified as a kind of radio source. Quasars also are called quasi-stellar objects (QSOs).
It has been predicted that the average daily discovery count will include about 100 asteroids, 30 stars possessing planets, 50 stars exploding in other galaxies and 300 distant quasars. GAIA may ultimately identify half a million new quasars.
Quasars were first identified as being high redshift sources of electromagnetic energy, including radio frequency and visible spectrum, that were point-like, similar to stars, rather than extended sources similar to galaxy....
Quasar
An unusually bright object found in the remote areas of the universe. Quasars release incredible amounts of energy and are among the oldest and farthest objects in the known universe. They may be the nuclei of ancient, active galaxies.
Even professional astronomers, after long nights observing distant galaxies, quasars, and pulsars will occasionally turn their gaze upon our sister world, the Moon.
Neutron Stars and Pulsars
Black Holes
Quasars
Exploding and Colliding Galaxies ...
QSO
QSO stands for Quasi-Stellar Object, and is a newer term for quasars (renamed to include the radio-quiet type of quasar).
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Quasar -- Quasi-stellar object observed mainly in radio waves. Quasars are extragalactic objects believed to be the very distant centers of active galaxies.
RA -- Right Ascension.
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43. BL Lac Object
Objects resemble quasars; thought to highly luminous cores of distant galaxies.
V/Vmax Test - A statistical method used to determine whether quasars have changed over time
Van Allen Belts - Two doughnut-shaped regions in the Earth's magnetosphere within which many energetic ions and electrons are trapped ...
You will also learn how stars "live and die", unusual astronomical events (variable stars, quasars, black holes, etc.), formation of stars, the Solar System and galaxies, movements of and distances to stars and galaxies, ...
An incredibly luminous object in the distant universe which releases an enormous amount of energy. Because of their immense distances, quasars appear as star-like points of light in the largest telescopes, and they are not fully understood.
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This set of abundances occurs with great regularity throughout the universe; it is found in such diverse objects as quasars, meteorites, and new stars. The Sun is roughly 90 percent hydrogen by number of atoms and 9.9 percent helium.
There may be at least three types of active galaxies, including Seyfert galaxies, quasars, and blazars (although these three may be the same type of galaxy viewed from different distances and perspectives).
BL Lacertæ objects. Objects which are strong emitters of infra-redradiation. They are very luminous and remote and are thought to have similar properties to quasars.
The importance of SS433 stems from the fact that we see great jets emerging from such energetic systems as quasars and galaxies (to be discussed later).
unified model: The attempt to explain the different kinds of active galaxies and quasars by a single model.
Thirdly, quasars, particularly the Lensed Quasar in Ursa Major near NGC3079. Then, planetary nebulae. They come in an endless variety. Finally, globulars. M15 is my favorite, particularly as one of its zillion stars has burst into tiny 15th mag.
 See also: Quasar, Galaxies, Universe, Light, Galaxy
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