.. _astroquery_atomic: ************************************** Atomic Line List (`astroquery.atomic`) ************************************** Getting started =============== "Atomic Line List" is a collection of more than 900,000 atomic transitions in the range from 0.5 Å to 1000 µm (source_). ``AtomicLineList`` has 13 parameters of which all are optional. In the example below, only a restricted set of the available parameters is used to keep it simple: ``wavelength_range``, ``wavelength_type``, ``wavelength_accuracy`` and ``element_spectrum``. The respective web form for Atomic Line List can be found at http://www.pa.uky.edu/~peter/atomic/. As can be seen there, the first form fields are "Wavelength range" and "Unit". Because astroquery encourages the usage of AstroPy units, the expected type for the parameter ``wavelength_range`` is a tuple with two AstroPy quantities in it. This has the positive side-effect that even more units will be supported than by just using the web form directly. In the following Python session you can see the ``atomic`` package in action. Note that Hz is actually not a supported unit by Atomic Line List, the atomic package takes care to support all spectral units. .. doctest-remote-data:: >>> from astropy import units as u >>> from astroquery.atomic import AtomicLineList >>> wavelength_range = (15 * u.nm, 1.5e+16 * u.Hz) >>> AtomicLineList.query_object(wavelength_range=wavelength_range, wavelength_type='Air', ... wavelength_accuracy=20, element_spectrum='C II-IV') LAMBDA VAC ANG SPECTRUM TT ... J J A_ki LEVEL ENERGY CM 1 float64 str4 str2 ... str5 float64 str18 -------------- -------- ---- ... ----- ----------- ------------------ 196.8874 C IV E1 ... 1/2-* 91300000.0 0.00 - 507904.40 197.7992 C IV E1 ... 1/2-* 118000000.0 0.00 - 505563.30 199.0122 C IV E1 ... 1/2-* 157000000.0 0.00 - 502481.80 Troubleshooting =============== If you are repeatedly getting failed queries, or bad/out-of-date results, try clearing your cache: .. code-block:: python >>> from astroquery.atomic import AtomicLineList >>> AtomicLineList.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.atomic :no-inheritance-diagram: .. _source: http://www.pa.uky.edu/~peter/atomic/documentation.html