Which of the following statements about rich clusters of galaxies (those with thousands of galaxies) is not true?
A) They are sources of X-ray emission due to the presence of hot, intergalactic gas.
B) There likely have been numerous collisions among the member galaxies at some time in the past.
C) Galaxies in the central regions are predominantly spirals, while elliptical galaxies roam the outskirts.
D) They often have a very large, central dominant galaxy near their center, perhaps formed by the merger of several individual galaxies.
E) The speeds of the galaxies in the cluster indicate that most of the cluster mass is dark matter.
Question 2
Black holes with masses greater than a million solar masses explain the extremely rapidly moving stars and gas in the cores of galaxies.
Indicate whether the statement is true or false
Changes in light quality with depth: (a) the rich colours on a shallow coral reef;
Barred Spiral Galaxies
Distant Galaxies
Aggregated red-cell clusters have a streamlined shape, leading to further viscos
In the summer of 1793, a yellow fever epidemic struck Philadelphia, killing nearly 4,000. Tens of th
This fisherwoman from Kerry, one of the poorest counties in Ireland, may have been one of the many t