Classifying galaxies

Big BangActive

galaxiesOur Local

GroupRandom

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Elliptical

What type of galaxy is on the far left hand side of the

tuning fork

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E0

A spherical galaxy (like M87) would be classified as

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Sa

A spiral galaxy with a large central bulge and tight arms

would be classified as

$800

E0 is circular, E7 is cigar shaped

How are an E0 and an E7 different?

$1000Sa hasLarger center (nucleus) and tighter

arms

How can you tell an Sa from an Sc

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increasing

Is the expansion rate of the universe increasing or

decreasing?

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Farther it is from us

Hubble’s laws tell us that the more red shift a galaxy has the_____________________ (farther or nearer) it is from us.

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expanding

Because the galaxies further from us are moving away faster, Astronomers know

that the universe is

$800An event that started the expansion of the universe

What is the Big bang?

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Contrast how dark matter and dark energy have different roles in the future of our universe.

Dark matter would slow down the universe’s expansion through gravitational influence, dark energy is accelerating the expansion.

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blazar

If we are looking at an active galaxy directly down through a jet are we seeing a radio galaxy or a blazar?

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Accretion disk (with infalling matter)

To provide radiate energy, active galaxies need both a

black hole and an

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Interactions with nearby galaxies or star clusters

What do active galaxies need to feed their central engines?

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Name the parts of an active galaxy

Jets, torus, accretion disk and black hole

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Look for jets, torus, accretion disk and black hole

Draw and label an active galaxy

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Small ellipticals

What type of galaxies compose our Local Group?

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Virgo

What is the nearest huge cluster of galaxies to our

Local Group

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Irregular

What type of galaxies are the Large and Small Magellanic

Clouds?

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Andromeda and the Milky Way

What are the largest members of the Local Group?

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45 galaxies total, Most are dwarf ellipticals and irregulars and three spirals: Milky Way, Andromeda and M33 are spirals

Describe the population, size and types of galaxies found in

our Local Group

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70%

How much of the universe might be dark energy?

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Luminous matter accounts for what percentage of the Universe’s total mass?

4%

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Galaxies are redshifting

The fact that photons are stretched as they travel and

space itself is expanding through time comes from the

fact that

$800distance

The greater a galaxies redshift the greater it’s

$1000

Mrs. Painter’s favorite astronomer is

Neil deGrasse Tyson