Blazars appear to produce more gamma radiation than other
types of active galaxies, but this may be because one of their jets is pointed toward Earth.
For decades, astronomers have tried to pin down why two of the most common
types of active galaxies, known as Type I and Type II galaxies, appear different when observed from Earth.
Known as Seyfert galaxies, these are
another type of active galaxy with relatively low mass black holes residing at their centers.
«Blazars are one
type of active galaxy,» said Marco Ajello, a professor of physics and astronomy and Paliya's advisor.
The particular
type of active galaxy seen then simply depends on the angle the accretion disk and dust ring are to the line of sight.
A third
type of active galaxy called BL Lacertae objects (BL Lac objects for short) are probably radio galaxies with their jets pointed right at us.
One
type of active galaxy is the Seyfert galaxy, named after Carl Seyfert who was the first to discover the peculiar spectra of these types of galaxies.
Blazars are
a type of active galaxy — about 1,000 have been cataloged [source: A Review of the Universe].
Not exact matches
This may explain why jellyfish
galaxies seem more likely than other
types of galaxies to have
active black holes at their centres.
Although the origin
of the gamma rays is still being investigated, their discovery suggests the flaring behaviour
of Cygnus X-3 is an even better analogue to that
of quasars and other
types of flaring
galaxies known as «
active galactic nuclei» (AGN) than previously thought.
Although both
galaxy types host voracious supermassive black holes known as
active galactic nuclei, which actively swallow matter and emit massive amounts
of radiation,
Type I
galaxies appear brighter to astronomers» telescopes.
«By putting us on a path to better understand the differences between the
galaxies that host
Type I and
Type II
active nuclei, this work will help us better understand how supermassive black holes influence the evolution
of their host
galaxies.»
One reason Morris and a growing number
of astronomers are mesmerized by the maelstrom at the core
of our
galaxy is that it doesn't fit neatly into any
of the models that scientists have painstakingly assembled over the decades to describe the various
types of «
active»
galaxies they observe.
The two different classes
of jet - spewing
active galaxies called blazars may, in fact, be a single hybrid
type that evolves over time, according to new research.
Active galaxies come in a variety
of types, including Seyfert
galaxies, radio
galaxies, and quasars.
Active galactic nuclei (AGN) are a
type of extremely bright
galaxy core seemingly fueled by powerful black holes actively gobbling large amounts
of material.
There are four classifications
of active galaxy, but the
type we observe may depend more upon our viewing angle than structural differences.