Centaurus A is a radio galaxy that has a visible galaxy at the center. This central elliptical galaxy of Centaurus A is encircled by a ring of gas and dust, different from most elliptical galaxies. The dust ring orbits about an axis that is perpendicular to the axis of rotation of the elliptical galaxy. What does this suggest about this central elliptical galaxy of Centaurus A?
a. The radio jets have caused the dust disk to be driven around the elliptical galaxy.
b. There are at least two black holes at the center of the elliptical galaxy.
c. Centaurus A is probably the result of a merger of an elliptical galaxy and a spiral galaxy.
d. Dust is produced as the jets interact with the intergalactic medium.
e. Elliptical galaxies often contain dust that forms a disk along their rotation axis.
Question 2
Mass is transferred from a normal star in a close binary system toward a white dwarf. The material that is transferred to the white dwarf forms a rapidly growing whirlpool of material known around the white dwarf known as a(n)
a. accretion disk.
b. Lagrangian point.
c. Algol paradox.
d. planetary nebula.
e. supernova remnant.
The Central Dogma of Genetics
The Lion Gate of Mycenae (detail)â€â€Âtwo lionesses flank the central column, c. 1300 B
The proportion of obese and extremely obese adults in the United States has increased over the past
A central port fuel-injection system.
The Visible Spectrum of Electromagnetic Energy
A longitudinal cut through the center of a shoot top of Coleus, a eudicot