How do astronomers know that the luminous regions of active nuclei of active galaxies are very small?
a. Their nuclei are much brighter than expected.
b. The orbits of stars near the center of the galactic nuclei are faster than expected.
c. The luminosity of the nuclei varies over short times.
d. The color of the nuclei is different than expected.
Question 2
Synchrotron radiation is produced
a. in planetary nebulae.
b. by red dwarfs.
c. in massive stars as their iron core collapses.
d. in supernova.
e. by neutrinos.
An ecological puzzle: the cicada, Diceroprocta apache, is active when air temperatures would appear
Position of the lungs within the thoracic cavity; anterior view illustrating regions of the lungs an
Giant Elliptical Galaxies
A Cluster of Galaxies
Far Oceania was the last of the regions of the world to be colonized by humans.
The effects of neonatal testosterone exposure on the size of the sexually dimorphic nuclei in male ...