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ASTR 1346 TEST 3 ACTUAL
QUESTIONS 2026 WITH VERIFIED
ANSWERS.
Virgo cluster
Nearest sizable cluster to the local group. Irregular in shape
with about 2500 galaxies
Qualities of superclusters
- contain dozens of individual clusters
- sizes up to 150 million ly
- 90-95% empty space
- largest coherent structures seen in the universe
Local supercluster
Roughly centered on the virgo cluster and contains several 10s
of 1000s of galaxies.
Filaments
- vast chains of superclusters
- occupy 10% of the universe
Voids
- empty bubbles
- 25-50 mpc in diameter
- 5-10x fewer galaxies than in superclusters
Grote Reber
Discovered the first Quasars in Illinois in 1936
Quasi-Stellar radio sources
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AKA as quasars. Normal hydrogen lines with extreme redshifts
Quasars/ quasi-stellar objects (QSO)
Galaxies with extremely luminous radio sources. Most luminous
objects in the universe
Qualities of quasars
- huge energy originates in a very small region
- varies in brightness in between weeks
- very high large redshift
- most distant objects in the universe
Quasar jets
Radio emission coming from radio lobes located on either side
of a galaxy in the center
Traits of normal galaxies
- dense central star cluster
- a composite stellar absorption line spectrum
- weak nebular emission lines
Active galaxies
1% of all galaxies. Huge amount of energy produced by nuceli
Traits of active galaxies
- bright, compact nucleus (looks like a star)
- strong, broad emission lines from hot, dense, highly excited
gas
- rapidly variable luminosity
BL Lacertae/ Blazars
Active and extremely bright cores of elliptical galaxies without
radio lobes. Brighter than quasars.
Accretion disk model
ASTR 1346 TEST 3 ACTUAL
QUESTIONS 2026 WITH VERIFIED
ANSWERS.
Virgo cluster
Nearest sizable cluster to the local group. Irregular in shape
with about 2500 galaxies
Qualities of superclusters
- contain dozens of individual clusters
- sizes up to 150 million ly
- 90-95% empty space
- largest coherent structures seen in the universe
Local supercluster
Roughly centered on the virgo cluster and contains several 10s
of 1000s of galaxies.
Filaments
- vast chains of superclusters
- occupy 10% of the universe
Voids
- empty bubbles
- 25-50 mpc in diameter
- 5-10x fewer galaxies than in superclusters
Grote Reber
Discovered the first Quasars in Illinois in 1936
Quasi-Stellar radio sources
, Page | 2
AKA as quasars. Normal hydrogen lines with extreme redshifts
Quasars/ quasi-stellar objects (QSO)
Galaxies with extremely luminous radio sources. Most luminous
objects in the universe
Qualities of quasars
- huge energy originates in a very small region
- varies in brightness in between weeks
- very high large redshift
- most distant objects in the universe
Quasar jets
Radio emission coming from radio lobes located on either side
of a galaxy in the center
Traits of normal galaxies
- dense central star cluster
- a composite stellar absorption line spectrum
- weak nebular emission lines
Active galaxies
1% of all galaxies. Huge amount of energy produced by nuceli
Traits of active galaxies
- bright, compact nucleus (looks like a star)
- strong, broad emission lines from hot, dense, highly excited
gas
- rapidly variable luminosity
BL Lacertae/ Blazars
Active and extremely bright cores of elliptical galaxies without
radio lobes. Brighter than quasars.
Accretion disk model
