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Introduction

This page contains tutorials to guide new ALMA users through some common types of data imaging and analysis using example ALMA datasets. In addition, we provide detailed guides to the calibration and imaging of some of the publicly-available ALMA Science Verification data that illustrate several different ALMA capabilities.

If you are a new user of CASA, take a look at Getting Started in CASA.

If you are new to CASAguides, start with How_To_Use_A_CASAGuide.

To extract scripts from these guides, see Extracting scripts from these tutorials.

Guides that have been updated to demonstrate CARTA will include this statement near the top:

This guide features CARTA, the “Cube Analysis and Rendering Tool for Astronomy,” which is the new NRAO visualization tool for images and cubes. The CASA viewer (imview) has not been maintained for a few years and will be removed from future versions of CASA. We strongly recommend using CARTA, as it provides a much more efficient, stable, and feature rich user experience. A comparison of the CASA viewer and CARTA, as well as instructions on how to use CARTA at NRAO, is provided in the CARTA section of the CASA docs.

General Imaging Tutorials

The following tutorials use example ALMA datasets to guide new CASA users through the basic steps required for imaging and self-calibration. ALMA data are delivered with standard calibrations applied and they are ready for imaging.

The following guides have been updated to run in CASA 6.5.4, which uses Python 3.

• A first look at imaging: This guide gives a first look at imaging and image analysis in CASA.
• A first look at self-calibration: This guide demonstrates continuum self-cal.
• A first look at spectral line imaging: This guide shows imaging of a spectral line.
• A first look at image analysis: This guide demonstrates moment creation and basic image analysis.

First look guides for older versions of CASA, as well as other guides that have stopped being updated, are located at Archived ALMA CASAguides.

New!

• A guide to automasking: This guide demonstrates the automasking functionality of tclean.
• A guide for utilizing ADMIT for your data: This guide discusses how to use ADMIT and customize it for your data.
• Examples for using the tclean CASA task for ALMA Imaging.

Information for ALMA users wishing to reprocess or reimage ALMA data

• Examples for ALMA Imaging Pipeline Reprocessing

• A guide for using the North American ALMA Manual Imaging Template

CASAguides for reducing ALMA Science Verification data

The links below lead to overview pages for each science verification observation. The guides themselves are linked from the overview pages. These guides are useful tools for those who would like to learn the process of calibration and imaging in detail.

The following ALMA science verification guides are being actively maintained, and have been validated for the CASA versions listed.

• AntennaeBand7: Mosaic of the galaxy merger NGC 4038/4039 (Antennae) at Band 7 (0.87 mm). Validated for CASA 6.5.4.
• M100_Band3: Demonstration of combining 12m-array, 7m-array, and Total Power data for M100. Validated for CASA 6.5.4.
• IRAS16293Band9: Mosaic of the protostellar cluster IRAS16293-2422 at Band 9 (0.45 mm). Validated for CASA 6.5.4.
• 3C286_Polarization: Demonstration of the reduction of ALMA continuum polarization toward the quasar 3C286. Validated for CASA 6.5.4.
• Sunspot_Band6: Demonstration of the reduction and imaging of the sunspot data at Band 6 (1.25mm). Validated for CASA 5.4.

Legacy guides and scripts for reducing ALMA Science Verification data

The following ALMA science verification guides and scripts have been validated for older versions of CASA, and will not continue to be updated for new CASA releases.

• TWHydraBand7: The protoplanetary disk source TW Hya at Band 7 (0.87 mm). Last validated for CASA 4.3.
• NGC3256Band3: The galaxy merger NGC 3256 at Band 3 (3 mm). Last validated for CASA 4.3.
• ALMA2014_LBC_SVDATA: Imaging scripts and details for the 2014 ALMA Long Baseline Campaign science verification data for Juno, Mira, HL Tau, and SDP.81. Last validated for CASA 4.2.2.
• File:BR1202 SV Band7 Calibration notes.pdf: Supplemental notes on the calibration of Science Verification target BR1202-0725 in CASA 3.3.

Additional information on relevant techniques and tools for ALMA data

• A Guide to CASA Data Weights and How to Ensure They are Correct for Data Combination

• Examples for using the new tclean CASA task for ALMA Imaging

• Analysis Utilities -- a Python module containing utilities for analysis and plotting.

• Solar System Models in CASA 4.0 and beyond

• Tutorials related to ALMA Solar Science Verification Data: CASA 4.7

Processing Cycle 0 data from the ALMA archive

A Guide to Processing ALMA Data for Cycle 0 (last checked in CASA 4.2) takes you through the steps of processing Cycle 0 data from the ALMA data archive. The guide describes some helpful hints for downloading the data, and describes the process all the way through imaging and self-calibration, and image analysis.

You can also get a look at example data calibration scripts used for Cycle 0 data at the following links. These were written for CASA version 3.4.

• TDM (128 channels/spw) File:TDM.example.ms.scriptForCalibration.py
• FDM (3840 channels/spw) File:FDM.example.ms.scriptForCalibration.py
• If you need to update 3.4 scripts to 4.2 or later, see more information here

Simulating ALMA data

Start here to learn about simulations: Guide To Simulating ALMA Data

Jump directly to examples: Simulating Observations in CASA

Old guides for other telescopes

Several older millimeter/submillimeter casaguides that may be of interest to users are listed in Past MM/Submm CASA Guides. Note that they are not currently being maintained and have been last validated for the CASA version listed beside each.

For CASA guides that focus on VLA data, please see Karl G. Jansky VLA Tutorials.

Other useful Information

• ALMA Science homepage
• CASA homepage including download and installation information
• ALMA Sensitivity Calculator
• CASA Hints, Tips & Tricks
• ALMA Pipeline Known Issues