.. _astroquery.hitran: ************************************ HITRAN Queries (`astroquery.hitran`) ************************************ Getting started =============== This module provides an interface to the high-resolution transmission molecular absorption database API (`HITRAN`_). The current version of the database contains a compilation of spectroscopic parameters for 49 molecular species along with their most significant isotopologues. Using the ``hitran`` module you can search transitions for a particular molecule in a given wavenumber range. Examples ======== This will download all transitions of the main isotopologue of water between the wavenumbers of 3400 and 4100 cm\ :sup:`-1`\ . The expected type for the parameters ``min_frequency`` and ``max_frequency`` is an AstroPy quantity. The data are returned as an `~astropy.table.Table` instance. .. doctest-remote-data:: >>> from astropy import units as u >>> from astroquery.hitran import Hitran >>> tbl = Hitran.query_lines(molecule_number=1, ... isotopologue_number=1, ... min_frequency=0. / u.cm, ... max_frequency=10. / u.cm) >>> tbl molec_id local_iso_id nu sw ... line_mixing_flag gp gpp int32 int32 float32 float32 ... bytes1 float32 float32 -------- ------------ -------- --------- ... ---------------- ------- ------- 1 1 0.072049 1.875e-30 ... 9.0 11.0 1 1 0.400571 2.528e-28 ... 27.0 21.0 1 1 0.741682 4.451e-25 ... 39.0 33.0 ... ... ... ... ... ... ... ... 1 1 9.640401 1.593e-34 ... 129.0 123.0 1 1 9.795592 1.794e-27 ... 39.0 45.0 1 1 9.834255 1.969e-35 ... 135.0 141.0 1 1 9.921502 6.136e-28 ... 13.0 15.0 Troubleshooting =============== If you are repeatedly getting failed queries, or bad/out-of-date results, try clearing your cache: .. code-block:: python >>> from astroquery.hitran import Hitran >>> Hitran.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 ============= .. automodapi:: astroquery.hitran :no-inheritance-diagram: .. _HITRAN: http://hitran.org