EVLA Continuum Tutorial 3C391

Overview

This article describes the calibration and imaging of a multiple-pointing EVLA continuum dataset on the supernova remnant 3C 391. The data were taken in OSRO1 mode, with 128 MHz of bandwidth in each of two widely spaced spectral windows, centered at 4.6 and 7.5 GHz, and were set up for full polarization calibration. To generate the full data reduction script described here, use the script extractor.

Getting hold of your data

The data are publicly available from the NRAO archive, under Project name TDEM0001. The archive lists two separate files; one taken on 2010-Apr-15, and the other on 2010-Apr-24. You will want to download the second file (file size 39.79 GB). This file contains data at the full 1-s time resolution.

Loading in your data

importevla(asdm='TDEM0001_sb1218006_1.55310.33439732639',vis='3c391_mosaic_fullres.ms',flagzero=True,shadow=True)

Examining your data

Before starting the calibration process, we want to get some basic information about the data set. To examine the observing conditions during the observing run, and to find out any known problems with the data, download the observer log. Simply fill in the known observing date (in our case 2010-Apr-24) as both the Start and Stop date, and click on the "Show Logs" button. The relevant log is labeled with the project code, TDEM0001, and can be downloaded as a PDF file.

listobs(vis='3c391_ctm_mosaic_10s.ms')

plotants(vis='3c391_ctm_mosaic_10s.ms',figfile='3c391_ctm_mosaic_antenna_layout.png')

Editing the data

flagdata(vis='3c391_ctm_mosaic_10s.ms',mode='quack',quackinterval=20.0,quackmode='beg')