The document is a chapter excerpt from an astronomy textbook about pulsars and black holes. It contains 8 multiple choice questions about pulsars, gamma ray bursters, Cygnus X-1, and properties of black holes such as the event horizon and what would happen if the sun was replaced by a black hole of the same mass.

1. © 2007 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students except by instructors using the accompanying text in their classes. All recipients of this work are expected to abide by these restrictions and to honor the intended pedagogical purposes and the needs of other instructors who rely on these materials. Conceptual Test PRS-Enabled Chapter 13 ASTRONOMY, A Beginner’s Guide to the Universe 5 th edition Chaisson McMillan

2. 1) extremely rapid rotation. 2) high temperature fusion reactions. 3) a narrow regular pulse of radiation. 4) high speed motion through the Galaxy. 5) an intense magnetic field. Question 1 Pulsars usually show ALL of the following except

3. Question 1 Pulsars usually show ALL of the following except Pulsars are neutron stars no longer undergoing fusion in their cores. 1) extremely rapid rotation. 2) high temperature fusion reactions. 3) a narrow regular pulse of radiation. 4) high speed motion through the Galaxy. 5) an intense magnetic field.

4. 1) emission nebulae. 2) giant molecular clouds. 3) globular clusters. 4) planetary nebulae. 5) open clusters. Question 2 Many millisecond pulsars lie within

5. 1) emission nebulae. 2) giant molecular clouds. 3) globular clusters. 4) planetary nebulae. 5) open clusters. Question 2 Many millisecond pulsars lie within The cores of globular clusters are densely packed with stars, suggesting that millisecond pulsars might result from “spinning up” as a result of stellar encounters. The core of globular cluster 47 Tucanae

6. Question 3 The lighthouse model explains how 1) pulsars can be used as interstellar navigation beacons. 2) the period of pulsation increases as a neutron star collapses. 3) pulsars have their rotation axis pointing toward Earth. 4) a rotating neutron star generates an observable beam of light.

7. 1) pulsars can be used as interstellar navigation beacons. 2) the period of pulsation increases as a neutron star collapses. 3) pulsars have their rotation axis pointing toward Earth. 4) a rotating neutron star generates an observable beam of light. Question 3 The lighthouse model explains how

8. 1) matter spiraling into a large black hole. 2) the collision of neutron stars in a binary system. 3) variations in the magnetic fields of a pulsar. 4) repeated nova explosions. 5) All of the above are possible. Question 4 One possible explanation for a gamma-ray burster is

9. 1) matter spiraling into a large black hole. 2) the collision of neutron stars in a binary system. 3) variations in the magnetic fields of a pulsar. 4) repeated nova explosions. 5) All of the above are possible. Question 4 One possible explanation for a gamma-ray burster is Gamma-ray bursts vary in length, and the coalescence of two neutron stars seems to account for short bursts.

10. 1) NASA’s latest X-ray orbiting telescope. 2) a millisecond pulsar with three planets. 3) the strongest X-ray eclipsing binary system. 4) a likely black hole binary star system. 5) the first gamma ray burster spotted in X-rays. Question 5 Cygnus X-1 is

11. 1) NASA’s latest X-ray orbiting telescope. 2) a millisecond pulsar with three planets. 3) the strongest X-ray eclipsing binary system. 4) a likely black hole binary star system. 5) the first gamma ray burster spotted in X-rays. Question 5 Cygnus X-1 is Cygnus X-1 is an X-ray source with one visible star orbited by an unseen companion of at least 10 solar masses, and very rapid changes in the signal indicating a small source.

12. 1) a beam of light. 2) a massive object. 3) neutrinos. 4) antimatter. 5) all of the above Question 6 The force of gravity can pull on

13. 1) a beam of light. 2) a massive object. 3) neutrinos. 4) antimatter. 5) all of the above Question 6 The force of gravity can pull on Gravity is described by general relativity as a bending of space, and all particles, including photons, move through warped space along curved paths.

14. 1) Earth’s orbit would not change. 2) Earth would be pulled into the black hole. 3) X-rays would destroy Earth. 4) Earth would be torn apart from the tidal force. 5) life would be unchanged. Question 7 If the sun was replaced by a one-solar-mass black hole

15. 1) Earth’s orbit would not change. 2) Earth would be pulled into the black hole. 3) X-rays would destroy Earth. 4) Earth would be torn apart from the tidal force. 5) life would be unchanged. Question 7 If the sun was replaced by a one-solar-mass black hole The force of gravity depends only on mass and distance, not the type of matter, or its size.

16. 1) is the point where X-rays emerge. 2) is the physical surface of the hole. 3) defines the outer edge of an accretion disk. 4) is measured by the Schwarzschild radius. 5) extends for millions of miles into space. Question 8 The event horizon of a black hole

17. 1) is the point where X-rays emerge. 2) is the physical surface of the hole. 3) defines the outer edge of an accretion disk. 4) is measured by the Schwarzschild radius. 5) extends for millions of miles into space. Question 8 The event horizon of a black hole The event horizon is the surface of an imaginary sphere around a collapsed object inside of which nothing, including light, can escape.