Skip to content

Latest commit

 

History

History
26 lines (14 loc) · 4.19 KB

Assignment01.md

File metadata and controls

26 lines (14 loc) · 4.19 KB
Raw

Assigment 1

Due: 29 September 2020, Revisions accepted until 30 September 2020.

Please make sure your homework has your name (both Chinese and pinyin). You are free to work with others in the class, but everyone should hand in their own assignment. You should submit your assignment as a Jupyter notebook or PDF by email to Kaixiang Wang. Please make sure the notebook is well documented with comments and descriptions of what you have done, not just codes and plots.

Recommended:

Download and read the Week 1 Notes. This covers the basics of galaxies and some language of astrophysics. If you are new to astronomy, please pay close attention to the terminology, as we will use it often. For those of you who are not familiar with magnitudes, colors, filters, etc., I encourage you to look at the SDSS exercise on color and light.

Install scientific Python. If you don't already have Python (and associated scientific libraries) installed on your computer, do it! Whether you choose Python 2.7 or >3.3 is up to you, but I recommend Python 3.x if you are new to Python. You can try the instructions at Python4Astronomers/Installing Scientific Python, or many other places online.

Become familiar with scientific Python. Look at the Python4Astronomers/Quick Tour. I suggest you look at the following referenecs and examples: a) Read a Table and Plotting, b) Curve Fitting with Scipy, and c) Synthetic Images. Some of you may be familiar with Python already, but for those who are not, I recommend you do these examples.

For basic learning, you can check out Google's Python Introduction, as well as many other resources online.

Work to be handed in:

  1. Manipulating galaxy images. The Sloan Digital Sky Survey is the largest public, homogeneous, digital sky survey. Using the SDSS Science Archive Server, go to the Imaging->Single Fields and search for the galaxy M101. Download the u-band, g-band, and r-band FITS images (links below the color image). Use these images to make a color image following the instructions from the Python4Astronomers Quick Tour, Make a Publication Quality Image. Save your color image. Does your color image look different from the one that SDSS produced? What are the wavelength ranges sampled by the u, g, and r bands? Think about what it means to make a color image. Set the range of intensity values in each filter to bring out the detail you wish to emphasize. This is best submitted as a Jupyter notebook plus a png of your final image.

  2. Exploring galaxies in the SDSS. Go to the SDSS Galaxies Exercise, and do Exercises 1-7. You may work with others in the class, but please do the initial classification (Exercise 1) by yourself (and turn in your classifications as part of your homework). The purpose of this exercise is for you to look at galaxies with your own eyes and see some of the variation in them, and to have familiarty with the SDSS SkyServer.

  3. Now that you have seen many galaxies, read Galaxy Formation and Evolution, Chapter 1, through the end of Sec 1.2 (pages 1-13). Based on this reading and what we discussed in class, write one paragraph describing the basic framework for the origin of galaxies and their evolution. How do we get galaxies, and what determines how they evolve with time?

During our meeting time on Week 2, we can discuss any or all of the material covered in this assignment.