Astroquery¶

This is the documentation for the Astroquery affiliated package of astropy.

Code and issue tracker are on GitHub.

Introduction¶

Astroquery is a set of tools for querying astronomical web forms and databases.

There are two other packages with complimentary functionality as Astroquery: pyvo is an Astropy affiliated package, and Simple-Cone-Search-Creator to generate a cone search service complying with the IVOA standard. They are more oriented to general virtual observatory discovery and queries, whereas Astroquery has web service specific interfaces.

Check out the A Gallery of Queries for some nice examples.

Installation¶

Astroquery has recently switched to a continuous deployment model, meaning that a release will be instantaniously available after each set of changes made to the code. The latest version of astroquery can be pip installed.

*Note: If an environment already has an older version of astroquery installed add --upgrade to make sure the latest version is installed.

$ pip install --pre astroquery

We also keep doing regular, tagged version for maintanence purposes. These can be then conda installed from the astropy conda channel.

$ conda install -c astropy astroquery

Building from source¶

The development version can be obtained and installed from github:

$ # If you have a github account:
$ git clone git@github.com:astropy/astroquery.git
$ # If you do not:
$ git clone https://github.com/astropy/astroquery.git
$ cd astroquery
$ python setup.py install

Requirements¶

Astroquery works with Python 3.6 or later.

The following packages are required for astroquery installation & use:

and for running the tests:

The following packages are optional dependencies and are required for the full functionality of the alma module:

The following packages are optional dependencies and are required for the functionality of the cadc module:

pyVO (>=1.0)

The following packages are optional dependencies and are required for the full functionality of the cds module:

The following packages are optional dependencies and are required for the full functionality of the mast module:

boto3

Using astroquery¶

All astroquery modules are supposed to follow the same API. In its simplest form, the API involves queries based on coordinates or object names. Some simple examples, using SIMBAD:

>>> from astroquery.simbad import Simbad
>>> result_table = Simbad.query_object("m1")
>>> result_table.pprint(show_unit=True)
MAIN_ID      RA         DEC     RA_PREC ... COO_QUAL COO_WAVELENGTH     COO_BIBCODE
          "h:m:s"     "d:m:s"           ...
------- ----------- ----------- ------- ... -------- -------------- -------------------
  M   1 05 34 31.94 +22 00 52.2       6 ...        C              R 2011A&A...533A..10L

All query tools allow coordinate-based queries:

>>> from astropy import coordinates
>>> import astropy.units as u
>>> # works only for ICRS coordinates:
>>> c = coordinates.SkyCoord("05h35m17.3s -05d23m28s", frame='icrs')
>>> r = 5 * u.arcminute
>>> result_table = Simbad.query_region(c, radius=r)
>>> result_table.pprint(show_unit=True, max_width=80, max_lines=5)
  MAIN_ID         RA          DEC      ... COO_WAVELENGTH     COO_BIBCODE
               "h:m:s"      "d:m:s"    ...
------------ ------------ ------------ ... -------------- -------------------
       M  42   05 35 17.3    -05 23 28 ...                1981MNRAS.194..693L
         ...          ...          ... ...            ...                 ...
V* V2114 Ori 05 35 01.671 -05 26 36.30 ...              I 2003yCat.2246....0C

For additional guidance and examples, read the documentation for the individual services below.

Available Services¶

If you’re new to Astroquery, a good place to start is the A Gallery of Queries:

A Gallery of Queries

The following modules have been completed using a common API:

These others are functional, but do not follow a common & consistent API:

There are also subpackages that serve as the basis of others.

WFAU Queries (astroquery.wfau)

Catalog, Archive, and Other¶

A second index of the services by the type of data they serve. Some services perform many tasks and are listed more than once.

Catalogs¶

The first serve catalogs, which generally return one row of information for each source (though they may return many catalogs that each have one row for each source)

Archives¶

Archive services provide data, usually in FITS images or spectra. They will generally return a table listing the available data first.

Simulations¶

These services query databases of simulated or synthetic data:

Line List Services¶

There are several web services that provide atomic or molecular line lists, as well as cross section and collision rates. Those services are:

Other¶

There are other astronomically significant services, that don’t fit the above categories. Those services are here:

Topical Collections¶

Some services focusing on similar topics are also collected in topical submodules:

Developer documentation¶

The modules and their maintainers are listed on the Maintainers wiki page.

The Astroquery API Specification is intended to be kept as consistent as possible, such that any web service can be used with a minimal learning curve imposed on the user.

The following Astroquery modules are mostly meant for internal use of services in Astroquery, you can use them for your scripts, but we don’t guarantee API stability.

License¶

Astroquery is licensed under a 3-clause BSD style license - see Licenses.

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