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35 Cards in this Set
- Front
- Back
The bottom up theory states that the galaxy formed...
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as a result of mergers between several smaller groups of gas, dust and stars.
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A dark region you see in the plane of the milky way is most likely to be produced by....
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a cloud of interstellar matter which contains dust particles.
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Open (galactic) star clusters..
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span a wide range of ages, some are quite young.
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What property do galaxies, start clusters, and stars have in common?
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(all of the above)
held together by gravity condensed out of clouds of gas are composed mostly of hydrogen |
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Edwin hubble recognized that the Andromeda nebula was a seperate "island universe" rather than a component of our own galaxy because..
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he used cephied variables to find it was a tremendous distance away
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Which of the following is a characteristic of the halo component of the milky way?
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randomly inclined stellar orbits
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Harlow shapely used globular clusters to show that the ...
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solar system is located far from the center of the milky way
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Astronomers use cephied variable stars to measure galaxies dtances because....
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thei luminosity can be determined from their period of variation
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based on the rotation curves of stars in spiral galaxies and the milky way, most of the mass in the galaxies is believed to be in the form of...
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dark matter
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Younger star have more heavy elements because
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heavy elements were made in the previous generation of stars
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______ galaxies contain large clouds of gas and dust, both young and old stars, but have no obvious spiral arms or nucleous.
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irregular
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The milky way galaxy is part od
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the local group
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hubbles law
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(all of the above)
tells us that the universe is expanding the universe was much smaller in the past neasure distance of distant galaxies and quasars more distant galaxies recede more rapidly than nearby ones |
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The rotation curve of a galaxy can be used to determine
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the mass of a galaxy
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Supermassive black holes are believed to be present in the center of
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(all of the above)
quasars milky way active galaxies |
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An elliptical galaxy could
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be formed from the collision and merger of spiral galaxies
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for which of the follwoing objects does hubbles law work?
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distant galaxies
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choose the best answer from the following: the one with the lease amount of gas or dust:
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elliptical
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quasars must be small because they
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have luminosities that fluctuate rapidly
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If the red shfts of quasars arise from the expansion of the univers
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a quasar must be very luminous
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Where is the center of the universe?
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There is no center
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Our galaxy is one of about thirty members of this collection of galaxies
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local group
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at 750 kpc away
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andromeda galaxy
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a collection of thousands of galaxies centered about 15 mpc away from us
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virgo cluster
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the cosmic background radiation comes frmo a time in the evolution of the universe
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when electrons began to recombine with nuclei to form atoms
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whether the universe is open, closed or flat depends on the _____ of the universe
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density
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the age of the universe can be determined if
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the hubble constant and density of the universe can be accurately determined
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if H equals 50 km/sec/mpc then a galaxy with a radical velocity of 2000 km/sec probably has a distance of
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40 mpc
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if the space telescope proved that hubbles constant is actually half as large as it is currently believed to be the implied age of the universe would be ______ the currently accepted value
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two times
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the universe is said to be closed if
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gravity is strong enough to stop the expansion in a finite time
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one quarter of the mass of the universe today is helium. this helium was produced
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by nuclear reactions occuring a few minutes after the big bang
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the hydrogen balmer line Hb has a wavelength 486.1nm in the lab it is observed in a quasar at 2430.5nm what is the shift of this quasar
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4
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a recently formed cluster of stars might be identified by the presence of
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(all of the above)
bright blue stars dusty patches hiding parts of the cluster glowing gas between the stars reflection nebulae around some stars |
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if galaxy A is four times more distant than galaxy B then according to the hubble law galaxy A will recede _____ than galaxy B
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4x faster
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besides hubbles observation of the expanding universe the best evidence for the big bang comes from
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the cosmic microwave background and the amount of helium, in the universe
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