Home - eakadams/ihow-hi GitHub Wiki

This wiki collects and explains the HI tutorials of the I-HOW workshop.

The test dataset used throughout this tutorial is the D-configuration data of Sextans B from the VLA ANGST sample. VLA ANGST was a project to observe the HI content of all star-forming galaxies within 4 Mpc, where these galaxies were all also observed with HST as part of the ANGST legacy program. You can find more information on VLA ANGST on their NRAO science website.

We will use CASA for this, and the CASA VLA Guides are a useful resource, in addition to the CASA Docs.

While this tutorial focuses on VLA HI data, MeerKAT follows the same principle, but with more baselines, and hence much larger datasizes.

The first steps of data retrieval, flagging and calibration are skipped during the HI portion of the workshop as they were covered earlier. You are welcome to also do these steps; you can start with "Load data into CASA" in the "Get the data" tutorial if you download the raw data from the tutorial google drive:

• Get the data
• Data inspection and flagging
• Cross calibration

The steps that we will focus on during the workshop are:

• Continuum subtraction
• Masking and cleaning
• Moment map creation

You can find the data and other relevant files for the workshop at this link