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.
Exploring the functional activity of brain regions by using fMRI scans.
Longer regions have more crossovers and thus higher recombinant frequencies
A permanent epicardial pacemaker. The pulse generator can be placed in subcutaneous pockets in the s
Interacting and Colliding Galaxies
Vertebral regions showing the four spinal curves.
Air-Mass Source Regions for North America