adrita-khan / astromundus2017_python

Lectures given at the Innsbruck University on December 2017

Python as a practical tool for Astrophysicists

The jupyter notebook

• Start the Jupyter notebook
• Shut down the Jupyter Notebook App
• Using the Jupyter notebook

Introduction to Python

• Scalar Objects in Python
• Variable assignment
• Comments
• Booleans
• Conditional statements: if, elif, else
• while loops
• Strings
• Containers: Tuples, Lists and Dictionaries
• Random numbers
• Mathematical functions
• Basic string operations
• for loops
• List comprehensions: Creating lists using for loops:
• break and continue statements
• Functions
• The input function
• Read and write ASCII files
• Exercises

Get help

• Python help() function
• Get help in a jupyter notebook
• Other sourcce of information

Numpy

• Numpy
• Create an array
• Operations
• Numpy: functions and methods
• Manipulating arrays
• Reshaping, resizing and stacking arrays
• Copy and "deep copy"
• Load ascii files
• Numpy reference guide
• Exercises

FITS files

• FITS File Format
• Read FITS file using astropy
• Convenience Functions
• modify an existing header
• Creating a new FITS image
• WCS

Python Classes

• Classes

Plotting with matplotlib

• Simple plot
• Save the figure
• lines
• subplots
• images
• scatter plot
• histogram
• Exercises

Introduction to Astropy

• The astropy project
• Quantities and units
• Constants
• Coordinates
• Tables

Model fitting

• Polynomials with numpy
• The astropy.modeling Package
• Fitting models using astropy

Working on a real problem

• The RGB slope - metallicity relation (Valenti et al. 2004)
• Download data from vizier
• Use one cluster as a test case
• put it all togheter in a function
• iterate on all obects

The Virtual Observatory

• The astroquery package
• Retrieve images from SkyView
• Retrieve complete catalogs from Vizier
• Query a sky region from a Vizier catalog

Python scripts