Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
The Milky Way
the milky way galaxy and other galaxies
| Question | Answer |
|---|---|
| What phenomenon is triggered by the passage of density waves through the material of a galaxy? | A local increase in star-formation rates along the line of the density increase |
| A typical Cepheid variable will have a period of light variation of approximately | 10 days |
| Evidence for dark matter in our Galaxy comes from | orbital periods of stars in the galaxy |
| The distance of our Sun from the center of the Galaxy is about | 8 kpc |
| There is a small source of intense radiation at the center of our Galaxy that may have a mass of about | 4,000,000 Suns |
| The Milky Way in the sky is | the visible part of the galactic disk |
| The approximate mass of our Galaxy (to a radius of 40 kpc) is about | 600 billion solar masses |
| Another star in our Galaxy, closer to the Galactic center, will revolve around that center | with a shorter period than the Sun |
| We can observe material within our Galaxy at the greatest distances using | radio telescopes |
| What type of matter is observed using radio telescopes in the mapping of the Galactic structure? | atomic hydrogen and the carbon monoxide molecule |
| How fast would a galaxy 600 megaparsecs away be moving with respect to us, according to Hubble's law? | 42,000 km/s |
| What is the Tully–Fisher relation? | It relates rotational speeds of galaxies as measured by the broadness of their emission lines to their luminosities. |
| What are the two objects observable from Earth's Southern Hemisphere that are known as the Magellanic Clouds? | They are dwarf irregular galaxies of a few billion stars each that orbit the Milky Way. |
| The type of galaxy that exhibits the largest range of sizes and masses is the | elliptical |
| Which of the following galaxies exhibits the greatest amount of gas and dust? | Sc |
| What characteristic of some lobe radio galaxies contributes to the idea that their energy emission is intermittent? | They display "blobs" of material along their lobes that indicates this material to have been ejected in bursts. |
| Quasars, lobe galaxies, and Seyfert galaxies | "all these are true" |
| In a lobe radio galaxy, the ultimate energy source for the entire galaxy is thought to reside | in the galaxy's center |
| Except for the nucleus, a Seyfert galaxy is likely to look much like | a spiral galaxy |
| Early attempts to explain the spectra of quasars were unsuccessful because the spectra were | redshifted by a larger amount than expected. |
| If quasars are among the most distant objects in the universe, then they must also be the | most luminous |
| A head–tail radio galaxy is one that has ______ significantly while ejecting its radio lobes. | moved |
| What is the defining characteristic of starburst galaxies? | They have a large number of young O- and B-type stars. |
| Intracluster gas has been observed in the __________ region of the spectrum. | x-ray |
| ____________ galaxies are relatively rare in regions of high galaxy density. | spiral |
| Most quasars became inactive about ___________ years ago. | 10 billion |
| What is the average distance between adjacent galaxies in a galactic cluster? | a few hundred thousand parsecs |
| What do astronomers learn from a redshift survey? | Since the redshift gives us the distance to galaxies, we can construct a three dimensional map of the galaxies. |
| Which law is used in the calculation of the combined galaxy masses of a binary galaxy system? | Kepler's third law |
| What is unusual about the results of mass determinations of clusters of galaxies? | There is much more mass than can be accounted for by the visible galaxies. |
Created by:
katesmarie
Popular Physical Science sets