Astronomy Chapter 13

Supermassive black hole:

A black hole whose mass exceeds 1000 solar mass

M87:

And example of an elliptical galaxy we can see from earth

All quasars have in common is that they....

Appear to be a small source of energy with red shifts that indicate they are far away

If a nearby galaxy still acts like a quasar today, the galaxy must be undergoing a....

Collision with another galaxy that is providing fresh fuel for its central black hole

Astronomers use the red shift and Hubble's law to....

Find the distance to a remote quasar

When a quasar shines with a lot of energy, where does this huge amount of energy come from?

From an accretion desk around a supermassive black hole

The massive black hole at the center of galaxies help....

New stars conform when the flow of particles from the black hole accretion disk or jets compress the material some distance away from the black hole and starts the clumping that leads to the formation of stars

Relationship between Black Hole Mass and the Mass of the Host Galaxy:

Observations show that there is a close correlation between the mass of the black hole at the center of a galaxy and the mass of the spherical distribution of stars that surrounds the black hole. That spherical distribution may be in the form of either an elliptical galaxy or the central bulge of a spiral galaxy

The energy emitting regions from quasars are so small because...

Quasars are the result of matter falling in the black hole the event horizons of even supermassive black holes are extremely small on the cosmic scale

After several decades of observation, astronomers have concluded that....

Quasars are very powerful and compact sources of energy at the center of distinct galaxies

After the discovery of quasars, the astronomers discovered that....

The Milky Way has a black hole at the center with enough mass for 4 million suns

3C 273:

The first quasar identified and the brightest in apparent magnitude, it is unusually luminous for being so nearby, and has by far the brightest optical jet known among quasars.

For galaxies that have supermassive black holes at the center....

The more mass of the galaxy, the more mass of the center of black holes

Kepler's third law:

The square of the orbital period of a planet is directly proportional to the cube of semimajor access of its orbit

The quasars demonstrate that....

The universe evolves with time. the number of quasars reached a max sometime ago and how the numbers have been declining

The astronomers think that....

There are fewer quasars today than there were billions of years ago. Quasars are scene when the supermassive black hole at the center of a galaxy has a lot of food to eat (stars and gas) and the amount of available food tends to decrease with time

redshift:

a phenomenon where electromagnetic radiation (such as light) from an object undergoes an increase in wavelength. "redshift" means an increase in wavelength, equivalent to a decrease in wave frequency and photon energy, in accordance with, respectively, the wave and quantum theories of light

The solar mass is...

a standard unit of mass in astronomy, equal to approximately 2×10³⁰ kg. It is used to indicate the masses of other stars, as well as clusters, nebulae, and galaxies. It is equal to the mass of the Sun

An accretion disk is...

a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is typically a star.

Chandra X-ray Observatory is a...

a telescope specially designed to detect X-ray emission from very hot regions of the Universe such as exploded stars, clusters of galaxies, and matter around black holes.

quasar:

an extremely luminous active galactic nucleus (AGN), in which a supermassive black hole with mass ranging from millions to billions of times the mass of the Sun is surrounded by a gaseous accretion disk.

Kinetic energy:

the energy of mass in motion, in physics the KE of an object is the energy that it possesses due to its motion.

The Fermi bubbles are...

two large structures in gamma-rays above and below the Galactic center. They are associated with the microwave haze around the Galactic center.

Quasars are...

Ø are the most distant objects in the universe, and so are among the earliest objects known to have formed in the young universe, more than 12 billion years ago. The most widely accepted notion is that quasars are in galaxies with active, supermassive black holes at their centers. However, because of their enormous distance, the 'host' galaxies appear very small and faint and are very hard to see against the much brighter quasar light at the center. Though a quasar might no be much larger than our solar system it releases as much energy as billions of stars.