Astronomers observe huge bubbles of hot gas, some over a thousand light-years across, in the Milky Way. What is their cause?
What will be an ideal response?
These huge bubbles arise from many supernovae occurring close together in both space and time and are called "superbubbles." The supernovae are correlated because stars tend to form in clusters and massive stars live for a relatively short time. Thus when the massive stars supernova, they are still relatively close together and do so within a few hundred thousand years of each other (which is a short time compared to Galactic timescales).
You might also like to view...
Carnot Engine: A real (non-Carnot) heat engine, operating between heat reservoirs at temperatures of 450 K and 270 K, performs 3.3 kJ of net work, and rejects 8.2 kJ of heat in a single cycle.(a) What is the thermal efficiency of this heat engine?(b) What is the maximum efficiency it could possibly have?
Fill in the blank(s) with the appropriate word(s).
The atomic number and mass number for calcium-39 are 20 and 39, respectively. How many neutrons are in one atom?
A) 1 B) 19 C) 20 D) 39 E) 59
An interval of one Celsius degree is equivalent to an interval of:
a. one Fahrenheit degree. c. 5/9 Fahrenheit degree. b. one kelvin. d. 5/9 kelvin.
Market justice is the foundation of public health
a. true b. false