Homework #7
ASTR 3800
Due April 5, 2016

I have pulled an image of M33 off the NASA Extragalactic Database. It was originally in FITS format. In order to open fits you must have access to an astronomy user's libraray. Getting access to that library of routines would be a hassle for many of us right now. So I opened up the image myself and saved it as an unformatted binary file called m33.dat.

Download the file from this site. The image is a 1000x1000 array of integers. Write a python procedure to open it read it into an array called 'image'. Plot the image to the screen. Change color tables to another one you like.

you will need this snippet of code to read the file:

data = fromfile('m33.dat', dtype=int16)
data_fortran = data.reshape((1000,1000),order="FORTRAN")

Save both images as a jpg's.

Make a contour plot that shows the galaxy. Save that as a jpg.

Then plot a line of intensities across the image. image[*,500]

Save that plot as a jpg.

Find the brightest point in the image. How bright is it? Where is it?

What is the typical brightness per pixel of the galaxy near its center?

Answer the last two questions and submit along with the images as attachments to get credit for the homework.