Astro 2201   Paper #3

Lect #2   Prof. Haynes     Due: Wed Nov 11th, 2009



You've just got a job in a publishing house that specializes in books for young teenagers. Your editor, the feared and respected Calpurnia I. S. Stiffaswood, challenges you with a task that will allow to show off your training in Astronomy at Cornell.

A book on "Cosmic Wonders" is being prepared to be used as a middle school textbook on general astronomy. In addition to the main content exposition, the book is to contain "boxes", of about 1000 words each, printed and double-spaced, illustrating in vivid detail special astrophysical concepts. You are to write one of such "boxes" to accompany the attached image. The general theme for the discussion you should prepare is "Supermassive Black Holes in the Local Group". You have quite a bit of latitude about what information you might include in your write-up, but keep in mind the audience and stick to information relevant to the theme.

Among the guidelines the editor provides you with are the following:

  • Be sure to explain what is seen in the image.
  • Be quantitative where you can be. You should not write out equations, but any numbers you use should be correct.
  • Previous sections in the book will explain the concept of light year, light month, light seconds etc., but not parsecs.
  • Previous sections in the book with explain black holes in general. Other boxes will present supernovae, X-ray binary stars and stellar mass black holes.
  • Terms like "Schwarschild radius", "escape velocity", "doppler shift", "Milky Way Galaxy" and "Local Group" will have been introduced.
  • Discuss at least three supermassive black holes in the Local Group and give quantitative data on their masses, distances from us, and other detail relevant to your discussion.
  • Also discuss basic information about the galaxies in which those SMBHs reside. Compare and contrast where you can.
  • Explain the methods used to infer the existence of the three supermassive black holes that you discuss. Give some general detail on the observations, the telescopes and the techniques used to estimate the masses of the SMBHs.
If you have any questions about what terms might or might not have been already introduced, please ask us for a ruling.

Remember, you are writing for smart children: be clear, be succinct, be entertaining. And if you use other sources, make sure you quote them with proper references.