How can you tell the difference between a Seyfert galaxy and a normal spiral galaxy?
Explanation: A Seyfert galaxy is a spiral galaxy with an active nucleus. An active galactic nucleus occurs when the supermassive black hole at the galactic centre has an accretion disc of dust and gas falling into the black hole.
What is the difference between a radio galaxy and a Seyfert galaxy?
Seyfert galaxies are visible galaxies with active nuclei. They have unusually bright core regions. Radio galaxies have active nuclei which emit mainly in the X Ray spectrum. These are normally associated with elliptical galaxies which have particularly large supermassive black holes.
What is the difference between a type 1 Seyfert galaxy and a type 2 Seyfert galaxy?
The nuclear spectra of Type 1 Seyfert galaxies show broad emission lines, which are indicative of a central concentration of hot gas that is expanding at speeds of up to thousands of kilometres per second. Type 2 Seyferts have strong emission lines, but they indicate more-modest velocities, less than 1,000 km/sec.
What is peculiar about the spectra of Seyfert galaxies?
There is also a spectroscopic definition of a Seyfert galaxy, which requires that they have strong and broad emission lines in their spectra (Seyfert 1943). Such lines are never seen in galaxies without bright nuclei, but there are some galaxies with bright nuclei that do not have such emission lines.
Which of the following is a characteristic of a Seyfert galaxy?
Which of the following is a characteristic of a Seyfert galaxy? The nucleus of a Seyfert galaxy is unusually bright compared with the spiral arms.
Are Seyfert galaxies irregular?
Irregular galaxies have some hints of organized spiral structures, but are loosely scattered. Active Galactic Nuclei is a term that describes four types of galaxies: Radio Galaxies. Seyfert galaxies.
How does a lenticular galaxy differ from a normal spiral galaxy quizlet?
How does a lenticular galaxy differ from a normal spiral galaxy? It has no spiral arms.
What is the primary difference between an active galaxy and a normal one quizlet?
What is the primary difference between an active galaxy and a normal one? An active galaxy's central black hole has lots of gas falling into it. A normal galaxy's black hole doesn't.
What is a Seyfert 2 galaxy?
Type II Seyfert galaxies have the characteristic bright core, as well as appearing bright when viewed at infrared wavelengths. Their spectra contain narrow lines associated with forbidden transitions, and broader lines associated with allowed strong dipole or intercombination transitions.
What are the characteristic properties of Seyfert galaxies?
Type II Seyfert galaxies have the characteristic bright core, as well as appearing bright when viewed at infrared wavelengths. Their spectra contain narrow lines associated with forbidden transitions, and broader lines associated with allowed strong dipole or intercombination transitions.
Are Seyfert galaxies radio loud?
Radio-loud Narrow-line Seyfert 1 (NLS1) galaxies are unique probes of the formation of powerful radio jets at extreme (near-Eddington) accretion rates and low black hole masses, in a regime very different from classical blazars and, therefore, not probed before.
What are the observational characteristics of active galaxies select all that apply quizlet?
What are the observational characteristics of active galaxies? (Select all that apply.) Seyfert galaxies, and some active galactic nuclei like quasars, show rapid brightness changes. Active galaxies have high luminosities for at least some wavelengths, such as radio and X-ray wavelengths.
What describes an elliptical galaxy?
Elliptical galaxies lack the swirling arms of their more well-known siblings, spiral galaxies. Instead, they bear the rounded shape of an ellipse, a stretched-out circle.
What are the three main types of active galaxies list the main characteristics of each?
What Kinds of Galaxies Are There? Astronomers classify galaxies into three major categories: elliptical, spiral and irregular. These galaxies span a wide range of sizes, from dwarf galaxies containing as few as 100 million stars to giant galaxies with more than a trillion stars.
What is the major difference between an elliptical galaxy and a spiral galaxy?
Elliptical galaxies are ellipsoids with no clearly visible internal structure. Spiral galaxies have a very dense nucleus and a region of stars bulging outwards from the disks and, therefore, called the central bulge. Elliptical galaxies also have dense centers, but they do not protrude from the body of the galaxy.
What is Leavitt’s Law explain how Hubble used it to prove that the Andromeda Galaxy lies beyond the bounds of the Milky Way?
How did Hubble use it to prove that the Andromeda Galaxy lies beyond the bounds of the Milky Way? Leavitt's law is a relationship between a period of a Cepheid variable star and its luminosity. Hubble observed Cepheid variables in the Andromeda Galaxy and obtained their luminosities using Leavitt's law.
What is the primary difference between an active galaxy and a normal one?
What is the primary difference between an active galaxy and a normal one? An active galaxy's central black hole has lots of gas falling into it. A normal galaxy's black hole doesn't.
What is the difference between the terms radio galaxy and active galaxy quizlet?
An active spiral galaxy with a bright, starlike nucleus and strong emission lines in its spectrum is categorized as a Seyfert galaxy. A radio galaxy has a bright nucleus and a pair of radio-bright jets that stream out in opposite directions.
What are the basic properties of Seyfert galaxies?
Seyfert Galaxies are spiral galaxies with unusually bright, tiny cores that fluctuate in brightness. They do not have radio lobes. Most are powerful sources of infrared radiation. In addition, some emit intensely in the radio, X ray, and gamma ray regimes.
What one characteristic do Seyfert quasar and Blazar galaxies seem to have in common?
All of the Active Galaxies (Seyferts, Radio Galaxies, Blazars, Quasars) have properties in common: bright nuclei and rapid variability.
Do Seyfert galaxies have jets?
NGC 1097, has four narrow optical jets coming out from its nucleus. NGC 1275, whose central black hole producing the lowest B-flat note ever recorded. NGC 1365, notable for its central black hole spinning almost the speed of light. NGC 1566, one of the first Seyfert galaxies classified.
Is the Milky Way a Seyfert galaxy?
Our galaxy isn't generally considered a Seyfert galaxy, or a particularly active galaxy at all. But the Milky Way is known to have a 4-million-solar-mass black hole at its heart, called Sagittarius A*, or Sgr A* (pronounced Sagittarius A-star).
What is the difference between an E6 galaxy and an E2 galaxy?
What is the difference between an E6 galaxy and an E2 galaxy? The E6 galaxy is more elliptical than the E2 galaxy.
What’s the difference between spiral and elliptical galaxies?
Spiral and barred spiral galaxies are subclassified by how tightly wound the spiral arms appear. Elliptical galaxies don't show any structure, but have a smooth ellipsoidal shape, appearing as a large spherical or elliptical ball of stars. Elliptical galaxies can be classified in terms of how long and thin they appear.
What are the differences between the 3 types of galaxies?
As their name suggests, elliptical galaxies are round or oval, with stars distributed fairly uniformly throughout. They have a bulge and halo, like spiral galaxies, but don't have the flat disk of stars. The stars in ellipticals tend to be older. Irregular galaxies have no identifiable shape or structure to them.
What are the differences between spiral and irregular galaxies?
A spiral galaxy consists of a spinning, flattened disk with arms that rotates very fast. An elliptical galaxy is the most common type of galaxy, has a roundish shape, and demonstrates little or no star formation. An irregular galaxy is a galaxy with no defined shape that has very young stars.
How are spiral galaxies and elliptical galaxies different quizlet?
Spiral galaxies have both young and old stars, whereas elliptical galaxies have only old stars. Among the large galaxies in the universe outside of clusters, most are spiral. Elliptical galaxies are bluer and contain more dust than spiral galaxies.
How do elliptical and spiral spectra differ?
These spectra lines are caused by the movement of electrons between energy levels in atoms. In general, galaxies can be divided into two different categories: elliptical and spiral galaxies. Elliptical galaxies have absorption lines, while spiral galaxies have emission lines due to the presence of interstellar gas.
What are two difference between normal and active galaxies?
Normal galaxies contain stars that are generally similar to those in our own Galaxy; and spiral galaxies have additional similarities to the Milky Way in their gas and dust content. Active galaxies show extra emission of radiation, and this is most apparent from the spectra.
What are the properties of a Seyfert galaxy?
Seyfert Galaxies are spiral galaxies with unusually bright, tiny cores that fluctuate in brightness. They do not have radio lobes. Most are powerful sources of infrared radiation. In addition, some emit intensely in the radio, X ray, and gamma ray regimes.