MOCs¶

MOC stands for Multi-Order Coverage map and is a standard in astronomy for showing survey coverage (see here for a tutorial on both HiPS and MOCS). MOCs of the VAST pilot survey are packaged into VAST Tools and are available to load for use within an analysis.

Info: mocpy

All MOCs are loaded as mocpy objects. Refer to the documentation of mocpy here to learn more about what can be achieved with the package, including how to plot a MOC onto a sky map.

The MOCs available to load are in VAST Tools are:

Tile
These are MOCs of the individual tiles that construct the overall pilot survey observation.
Field
These are groups of tiles that construct a unique field used in the pilot survey. For example, the VAST pilot survey phase 1 used a survey footprint of 6 distinct fields.
Epoch
The entire footprint observed for a single epoch of the pilot survey.
Full Pilot STMOC
The entire VAST Pilot survey contained in a MOC that contains Space and Time information - a STMOC. See this document for information on STMOCs.

Using the MOC Component¶

Info: MOCs Example Notebook

A notebook example of using the MOCs component can be found in the example notebooks section here.

Info: VAST Pilot Survey Details

Full details of the design of the VAST Pilot survey can be found these wiki pages (askap-vast GitHub membership required to access):

The MOC component is known as VASTMOCS in VAST Tools a VASTMOCS instance can be initialised with:

Example

from vasttools.moc import VASTMOCS

vast_moc = VASTMOCS()

No arguments are required as all the MOCs can be loaded from this object.

Available Methods¶

The following methods are available with the VASTMOCS class.

Info: Code Reference

Each method below has a link to the Code Reference section which provides full details of the method, including the arguments.

load_pilot_tile_moc¶

Code reference.

This loads the MOC of a single tile, returning a mocpy.MOC instance.

Example

Loading the MOC for field VAST_0012-06A.

tile_moc = vast_moc.load_pilot_tile_moc('VAST_0012-06A')

load_pilot_field_moc¶

Code reference.

This loads the MOC of a VAST pilot survey field, returning a mocpy.MOC instance.

Example

Loading the MOC for field 1:

field_moc = vast_moc.load_pilot_field_moc('1')

load_pilot_epoch_moc¶

Code reference.

This loads the MOC of a VAST pilot survey epoch, returning a mocpy.MOC instance. Enter as string with no zero padding on the epoch.

Example

Loading the MOC for epoch 7x:

epoch_moc = vast_moc.load_pilot_epoch_moc('7x')

load_pilot_stmoc¶

Code reference.

This loads the STMOC of all the VAST pilot observations, returning a mocpy.MOC instance.

Example

Loading the STMOC:

stmoc = vast_moc.load_pilot_stmoc()

load_survey_footprint¶

Code reference.

This loads a MOC of the footprint of either the pilot or full VAST survey.

Example

Loading the survey footprint MOC:

pilot_moc = vast_moc.load_survey_footprint('pilot')
full_moc = vast_moc.load_survey_footprint('full')

query_vizier_vast_pilot¶

Code reference.

This searches the provided Vizier table for sources that are in the VAST pilot survey epoch 1 footprint, returning a astropy.table.Table instance.

Example

To search for matches in the SUMSS catalogue (Vizier id: VIII/81B) the command would be:

vast_sumss_sources = vast_moc.query_vizier_vast_pilot('VIII/81B')

Last update: May 16, 2023
Created: July 23, 2021