FIRST Queries (astroquery.image_cutouts.first)

Getting started

This module may be used to fetch image cutouts in the FITS format from the Faint Images of the Radio Sky at Twenty-cm (FIRST) VLA radio survey. The only required parameter is the target you wish to search for. This may be specified as a name - which is resolved online via astropy functions or as coordinates using any of the coordinate systems available in astropy.coordinates. The FITS image is returned as an HDUList object. Here is a sample query:

>>> from astroquery.image_cutouts.first import First
>>> from astropy import coordinates
>>> from astropy import units as u
>>> image = First.get_images(coordinates.SkyCoord(162.530*u.deg, 30.677*u.deg,
...                                                frame='icrs'))
>>> image

[<astropy.io.fits.hdu.image.PrimaryHDU object at 0x11c189390>]

There are some other optional parameters that you may additionally specify. For instance the image size may be specified by setting the image_size parameter. It defaults to 1 arcmin, but may be set to another value using the appropriate Quantity object.

Troubleshooting

If you are repeatedly getting failed queries, or bad/out-of-date results, try clearing your cache:

>>> from astroquery.image_cutouts.first import First
>>> First.clear_cache()

If this function is unavailable, upgrade your version of astroquery. The clear_cache function was introduced in version 0.4.7.dev8479.

Reference/API

astroquery.image_cutouts.first Package

FIRST Image Query Tool

Classes

FirstClass()

Conf()

Configuration parameters for astroquery.image_cutouts.first.