ATNF Pulsar Data Archive: Users Guide

This page is still under construction!

Introduction

The ATNF Pulsar Data Archive exists to allow astronomers access to observations of pulsars made with the Parkes radio telescope in the last two decades.

The data comes either from the Parkes Southern Pulsar Survey (the "70cm Survey", Manchester et al. 1996, MN 279, 1235), or from observations of known pulsars with one of the Parkes instruments (WBC, DFB, CPSR2). We hope to make available data from the Multibeam Survey at some point in the near future.

Using the archive

Overview

The Pulsar Data Archive provides a means for accessing observational data. Queries are made according to position on the sky and can be filtered by parameters such as data type and date.

To download data, selections are made from the query results. These are stored in a "cart" from which they can be downloaded as a tar file.

Data access and availability

ATNF pulsar data has a month proprietary period. All data older than this is publicly available, but access to proprietary data is restricted to those involved in the project under which the data was taken.

To manage the access to data, we have two forms of access to the archive. Anonymous access allows access only to the non-proprietary data. Proprietary data from a project you were involved in is obtained by logging in with your email and OPAL password, with the same OPAL account you use for proposals. This will then verify that you were involved in the project (by use of the Project ID), and allow you access.

Note (Feb 18): At present, the use of OPAL authentication has not been enabled, and anonymous access is the only option (unless you obtained a login for the testing version of the archive). This will be rectified in the very near future.

How to make queries

The data is queried primarily on positional information. The user gives either a pulsar name or a RA/Dec position, plus a search radius. The pulsar name takes precedence over the RA/Dec position given, so to search by RA/Dec, make sure the pulsar name field is empty.

The search-by-name searches for files that either have the given pulsar name in their "src_name" field, or have an RA/Dec position within the given search radius of the pulsar. The pulsar's position is taken from the ATNF Pulsar Catalogue.

Important: When doing the position search, the beam size of the telescope is taken into account. For a given observation, there is a primary beam size, and if the primary beam intersects the search circle (i.e. the circle on the sky centred at the query position with radius equal to the search radius), then the observation is accepted.

Query options

The query can be refined according to a number of parameters:

Time: A time range for the observations can be specified. The default values for this are given by the extent of the archive (ie. the default "from" date is the earliest observation, and the default "to" date is the latest).
Obs Mode: The query can be restricted to only survey data (just the 70cm survey for the moment), or only timing data (ie. observations of a particular pulsar). The default is both types.
Data Type: One of the different instruments (WBC, DFB, CPSR2, FB_1BIT) can be selected. The default is all of them.
Frequency range: Multiple frequency bands can be selected from the list.

The list of options on the left hand side shows the possible parameters that can be returned with your query. Note that not all fields will have values for all observations.

The list can be ordered according to a limited range of these parameters: distance (from the query position - the default), date of observation, frequency, and filename.

Finally, it is possible to search for calibration observations that were taken within a given time period of the science observations. To do so, check the box under "DISPLAY OTHER DATA" and set the time limit in which to search for Cals (the default is 30 minutes).

Navigating around the archive

The first page returned when you submit your query is the list of the first (up to) 20 observations. Only 20 observations are displayed at a time. You can move through the list by clicking on the page numbers above or below the table.

Note that a limit of 1000 results is returned for the query -- if you are getting more than this, perhaps you can afford to narrow your search!

In the top right, you will find information on the number of files and total size of the cart, as well as a navigation icon. When the Query Results page is displayed, the icon shown is that of the cart. Alternatively, when the list of cart items is displayed, the icon shown is that of the results table. Clicking on the icon takes you to the page depicted.


Cart Icon	Table Icon

Viewing profiles of pulsars

For some types of data, it is possible to view a pre-scrunched pulse profile. To do so, select the observations using the check boxes in the table, and select "View selected profiles" from the drop-down menu. This will display profile plots for all selected observations, unless they are unable to be pre-scrunched (for instance, survey observations).

To return to the results table, click the table icon at top right.

Downloading data

Since there can be a large number of query results, spread over many pages, we have implemented the observation cart to act as a staging post for downloading data. Desired data is first saved to the cart using the drop-down menu, by selecting its check box. From the cart page, the drop-down menu offers the option of downloading either just the data or the data plus any cals that have been found. The data is returned in a tar file that can be saved to a local disk.

Caveats

The archive is still in a developmental stage, albeit a fairly complete one. The main area that needs some work is that many fields for a lot of the data files are not filled in. This will be rectified in the near future, but be aware that not all information will be present. Also note that not all fields can be filled in for each data file: e.g. survey data cannot have a period defined.