Baylor Astronomy Test 4 - Russell, Astronomy Exam 4 - Dwight Russell, Astronomy Test 4 Dr. Russell, astronomy russell test 4

Réussis tes devoirs et examens dès maintenant avec Quizwiz!

Bulge

- center of the galaxy - football shape - population II stars - little gas and dust - supermassive black hole at the center

Disk

- flattened shape, spiral arms (pop I) - both population I and population II stars - interstellar gas and dust

'Rungs' in the Distance Ladder

1. The radius of the Earth 2. Size, shape, and location of the moon 3. Size and location of the sun 4. Distances from the Sun to the planets 5. The speed of light 6. Distance to nearby stars 7. Distance to moderately distant stars 8. Distances to very distant stars 9. The shape of the universe

MW: Size

100 thousand light years across

what is the size of the milky way (in light years)?

100,000 light years

MW: Sun's position

2/3rds of the way out from the center (takes 230 million years for the sun to orbit the MW

How many stars are there in the milky way?

200 billion

MW: Stars

200 billion stars

Number of Stars in the Milky Way

200 billion stars

how many years does it take the sun to orbit the milky way?

230 million

How long does it take for the sun to go around the milky way once?

230 million years

How long does it take the sun to go around the Milky Way once?

230 million years

what is an elliptical galaxy

3 dimensional, football shaped, very little gas and dust,

Elliptical galaxy

A galaxy shaped like a round or flattened ball, generally containing only old stars. stars are distributed in an elliptical shape. pop II stars, hardly any gas or dust, smooth and elliptical in appearance, no disk, old stars only.

Irregular Galaxy

A galaxy that does not have a regular shape to fit Hubble's classification scheme. Pop I stars, young blue stars, gas and dust, galaxies in collision, no definite structure.

1. Planck Epoch

A mystery partly because we lack a quantum theory of gravity

Planck Epoch

A mystery partly because we lack a quantum theory of gravity

Planck Epoch

A mystery partly because we lack a quantum theory of gravity.

Size of the milky way

About 100,000 light years across

7. Dark Ages

Atoms exist but stars don't

Dark Ages

Atoms exists but stars don't

Dark Ages

Atoms exists but stars don't.

6. Photons, Nucleosynthesis and the Cosmic Background Radiation

Atoms form (Hydrogen and Helium) and Cosmic Background Radiation 'decouples' from matter

Photons, Nucleosynthesis and the Cosmic Background Radiation

Atoms form (Hydrogen and Helium) and Cosmic Background radiation ' decouples ' from matter

Protons, Nucleosynthesis and the Cosmic Background Radiation

Atoms form (Hydrogen and Helium) and Cosmic Background radiation 'decouples' form matter.

MW: Type of Galaxy

Barred Spiral

DL: Nearby Galaxies

Cepheids

Nearby Galaxies

Cepheids

Nearby galaxies

Cepheids

Halo

Contains Globular clusters, is spherical in shape, contains pop. II stars and very little interstellar gas and dust.

Rich Cluster

Contains thousands of individual galaxies

Tully-Fisher relation

Distant standards

Why are infrared and radio telescopes the instruments of choice for studying the galactic center?

Dust in the plane of the Milky Way obscures observations at other wavelengths.

The astronomer who originally classified galaxies into S, E, and Irr was

Edwin Hubble.

A galaxy with little cool gas or dust and no evidence of ongoing star formation is most likely a(n)

Elliptical

Which of the following types of galaxies has experienced no significant star formation during the last 10 billion years?

Elliptical

Compared to the spirals, elliptical galaxies tend to be more dusty. T/F

False

Globular clusters trace out the structure of the Galactic disk. T/F

False

Irregulars typically have very few blue stars. T/F

False

Most elliptical galaxies contain only young stars.T/F

False

Most galaxies are spirals like the Milky Way. T/F

False

Most galaxies are spirals. T/F

False

On average, elliptical galaxies are richer star forming regions than spirals. T/F

False

The Galactic halo contains as much gas and dust as the disk. T/F

False

2. The Grand Unification Epoch

Forces except gravity are unified

The Grand Unification Epoch

Forces except gravity are unified

What is the criterion for a group of galaxies to be considered a cluster?

Galaxies in a cluster are bound together by their mutual gravitational pull.

Shapely used what to determine the size and position of the center of the Milky Way?

Globular Clusters

What are the shapes and regions of the Milky Way?

Halo, Disk, Bulge

Which type of star is common in the spiral arms of our Galaxy, and found almost nowhere else?

High-mass O and B stars

DL: Further out

Hubble's Law

Farthest objects

Hubble's law

What is the sun's position in the milky way?

In the disk, about 2/3 out from the center

What effect does a spiral density wave have on the material it encounters?

It slows the material down, causing it to compress and heat up, assisting gravity in forming stars.

DL: Milky Way

Main-Sequence Fitting

Milky Way

Main-sequence fitting

Self-Propagating star formation for spiral arm formation

Need a gas cloud that starts to collapse on itself. SuperNova explosion causes the next supernova to form

DL: Nearby Stars

Parallax

Nearby Stars

Parallax

DL: Solar System

Radar Ranging

Solar System

Radar ranging

Which of the following is not one of Hubble's types of galaxies?

Seyfert spirals

"Modern" Era

Stars form - Quantum fluctuations at the time of inflation determines the distribution of matter in the universe. Denser areas are where stars will form. Gravity is the major large-scale force

8. Modern Era

Stars form. Quantum fluctuations at the time of inflation determines the distribution of matter in the universe. Denser areas are where stars will form. Gravity is the major large-scale force.

Virgo Cluster

The closest cluster of galaxies to our local cluster. Contains roughly 2000 galaxies.

Size of the Milky Way

The disk of the Milky Way galaxy is about 100,000 light years in diameter (one light year is about 9.5 x 1015 meters), but only about 1000 light years thick

Which of the following is NOT a difference between the disk and the halo of the Galaxy?

The halo population stars are primarily red in color, and there are no red stars in the disk.

What did a major discovery made by Harlow Shapley using RR Lyrae stars and globular clusters establish?

The size of the Galaxy an the Sun's position in it.

Density wave theory for spiral arm formation

The spiral arms are regions where the gas and dust are slightly denser so when objects move slowly in it they get compressed like a traffic jam (stars are like the cars) the traffic jam will be there but they are different cars

Which of the following best compares the motion of stars in the halo to the motion of the stars in the disk of the Galaxy?

The stars in the halo move in randomly-oriented orbits, while the disk stars generally stay confined to moving in the disk.

Which of the following statements describes the orbits of stars within most elliptical galaxies?

They have random orbits in three dimensions.

Cepheid variables can be used to determine the distances to the nearest galaxies. T/F

True

Herschel's attempt to map the Milky Way by counting stars led to an inaccurate estimate of the Galaxy's size because he was unaware of absorption by interstellar dust. T/F

True

Irr II galaxies may be the result of a collision, or close encounter, of two normal galaxies. T/F

True

Irregular galaxies, although small, have large star-forming (HII) regions and much ongoing star formation for their size. T/F

True

M31 in Andromeda is a bigger version of our Galaxy, and the largest member of the Local Group. T/F

True

Stars and gas in the Galactic disk move in roughly circular orbits around the Galactic center. T/F

True

The Galactic halo contains only old stars. T/F

True

The orbit of the Solar System around the Galaxy is similar to that of a planet, almost circular and in the galactic plane. T/F

True

Unlike spirals, elliptical galaxies do not contain a flattened disk. T/F

True

DL: Galaxy Clusters

Tully - Fisher Relation; distant standards

Which of these standard candles has been used to determine distances to the most distant galaxies?

Type I supernovae

The inflationary Epoch

Universe expands rapidly smaller than a proton to bigger than a melon - Supported experimentally

3. The Inflationary Epoch

Universe expands rapidly smaller than a proton to bigger then a melon - supported experimentally

4. Electroweak Epoch

Weak and electromagnetic forces act as one

Electroweak epoch

Weak and electromagnetic forces act as one

Electroweak epoch

Weak and electromagnetic forces act as one.

The Quark, Hadron and Lepton Epoch

What we think of a "normal" elementary particle form and survive

The Quark, Hadron, and Lepton Epoch

What we think of a "normal" elementary particle form and survive.

5. The Quark, Hadron, and Lepton Epoch

What we think of as "normal" elementary particle form and survive

Galaxy Clusters

White Dwarf Supernovae

A telescope searching for newly formed stars would make the most discoveries if it were pointed

Within a spiral arm

Pop I star

Young stars, typically bright blue and in the disk. Around interstellar gas and dust. Formed relatively recently.

what is a spiral arm?

a distribution of material in a pinwheel shape design

what is density?

a measure of compactness

Local group

a new level of structure in the universe above the scale of our galaxy

what is the sun's position in relation to the milky way?

about 8kpc from center (in the disk, 2/3 of the way out from center)

what is the shape of the milky way?

barred spiral

what are the three regions of the milky way?

bulge, disk, and halo

what are the characteristics of a bulge?

center of galaxy, supermassive black hole at center, football shape, population II stars, little gas/dust

Virgo Cluster

closest rich cluster to us hundreds of galaxies irregular shape large gravitational pull

what is the local group cluster?

cluster that contains milky way

Pop I

contain young bright and blue stars; young lives; surrounded by interstellar dust

Population I Stars

contain young stars, all colors including blue gas and dust present

what is the self propagating star formation theory?

creation & explosion of stars can create waves to trigger next round of star formation (possible spiral structure cause)

what could be considered similar to a traffic jam?

density wave theory

what is the seventh rung on the distance ladder?

distance between moderately distant stars

what is the sixth rung on the distance ladder?

distance between stars

what is the fourth rung on the distance ladder?

distance between sun and planets

what is the eighth rung on the distance ladder?

distance between very distant stars

Which type of galaxy exhibits the largest range of sizes and masses?

elliptical

a galaxy with very little or no interstellar gas and dust is _________

elliptical

what kind of galaxy exhibits a large range of sizes/masses?

elliptical

Which of these would be made up of only Population II stars?

elliptical galaxies

what are the three types of galaxies?

elliptical, spiral, irregular

what happened in the inflationary epoch?

expansion. size of a proton -> size of a melon

T/F irregular galaxies are big

false

Spiral Galaxy/ Barred Spiral Galaxy

flat mix (Pop I) irregular in shape; mainly galaxies in collision

what are the characteristics of a disk?

flat, spiral arms, population I and II stars, interstellar gas/dust

Galactic Disk

flattened shape, spiral arms, both pop I and pop II stars, interstellar dust and gas, pop I stars associated with spiral arms

what happened in the grand unification epoch?

forces were unified

Shapely methods

globular clusters contain millions of stars, can be spotted at large distances and can help determine edge and center of galaxy

Self Propagating Stars

going super nova to make the next generation of stars

what is the oldest component of a galaxy?

halo

what makes up the space between galaxies in a cluster?

hot gas & dark matter

how many stars are in the milky way?

hundreds of billions (200 billion)

Rich Clusters

hundreds to thousands of galaxies large gravitational pull

what kind of galaxy has a lot of gas/dust?

irregular

what kind of galaxy has a lot of star production?

irregular

what kind of galaxy is made up of mainly population I stars?

irregular

Irregular Galaxy

largest percentage of population I and gas and dust other galaxies colliding with each other low mass high gas content and high star formation

Poor clusters

loosely held together, local group

Milky way

main sequence fitting

how do you determine position, or distance of the milky way?

main sequence fitting

Spiral Galaxy

mix of stars halo, bulge, galactic disk

what is the second rung on the distance ladder?

moon

Pop II

older stars, long life, little gas and dust in the area

Population II Stars

older stars, yellows and reds in color very little gas and dust

population II stars

older, yellow and red, long lifetime stars

Self-propagating star formation

one generation dies, new ones come; waves of stars; requires supernova explosions

Which property is common to spiral galaxies?

ongoing star formation and emission nebula in the arms

Poor Clusters

only a handful of galaxies, low mass, irregular in shape

Nearby stars

parallax

what is used to measure distance to nearby stars?

parallax

what epoch came first in the big bang?

planck epoch

what kind of cluster doesn't have as many galaxies in it?

poor

what kind of cluster has fewer galaxies because it has lower mass?

poor

what kind of cluster tends to be more irregularly shaped?

poor

Local Group

poor cluster milky way galaxy is a part of

what kind of star can you associate a spiral arm with?

population I

Elliptical Galaxy

population II stars low star formation, globular clusters, little gas or dust old stars, radial star motion

Pop II star

population of older stars, yellow and red, like globular clusters, with low metals, very little gas and dust.

Solar system

radar ranging

what is the first rung on the distance ladder?

radius of the earth

Elliptical Galaxy

random shaped

what was the distance ladder created for?

relate distances on a variety of scales

what kind of cluster has a lot of galaxies in it?

rich

what is the ninth rung on the distance ladder?

shape of the universe

Compared to our own Galaxy, elliptical galaxies

show no evidence of ongoing star formation.

what is the fifth rung on the distance ladder?

speed of light

what are the characteristics of a halo?

spherical, globular clusters, population II stars, little gas/dust

what kind of galaxy has a dense nucleus?

spiral

what kind of galaxy has an extended halo?

spiral

what kind of galaxy has spiral arms?

spiral

what kind of galaxy has a flattened disk?

spiral (also has spiral arms)

What is the shape of the milky way?

spiral galaxy

Spiral/Barred Galaxy

spiral galaxy in which a bar of material passes through the center of the galaxy, with the spiral arms beginning near the ends of the bar.

what is a barred spiral shape?

spiral galaxy with a central bar shape

what is the third rung on the distance ladder?

sun

where does a spiral arm originate?

the galaxy's center

Which is the oldest component of the Galaxy?

the halo

what is our galaxy?

the milky way

what is the density wave theory?

the stars move to denser regions but the spiral arms remain (greater mass density and increased pressure)

Density Wave Theory

traffic jam; cars = stars; stars move to denser regions; in and out, but spiral arm remains; young stars

T/F elliptical galaxies contain a lot of old stars

true

Galaxy clusters

tully fisher distant standards

what is the closest cluster to us?

virgo

what was the electroweak epoch?

weak and electromagnetic forces acting as one

what was the dark ages?

when atoms existed but stars did not

Clusters

where galaxies reside; MW is in the "local group" (a poor cluster); Rich clusters: Virgo cluster- big, a lot going on, giant elliptical galaxies

what kind of stars do elliptical galaxies have a lot of?

yellow pop II

was the inflationary epoch proven?

yes

what kind of stars do irregular galaxies have?

young blue stars

population I stars

young, bright blue, short lifetime stars


Ensembles d'études connexes

AP Art History Chapter 1 Test Part 1

View Set

csd 425 exam 3 pre/post class quizzes

View Set

Spanish Countries Geography Facts

View Set