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.
>>> 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_type='Air', wavelength_accuracy=20, element_spectrum='C II-IV')
<Table rows=3 names=('LAMBDA VAC ANG','SPECTRUM','TT','TERM','J J','LEVEL ENERGY CM 1')>
array([(196.8874, 'C IV', 'E1', '2S-2Po', '1/2-*', '0.00 - 507904.40'),
(197.7992, 'C IV', 'E1', '2S-2Po', '1/2-*', '0.00 - 505563.30'),
(199.0122, 'C IV', 'E1', '2S-2Po', '1/2-*', '0.00 - 502481.80')],
dtype=[('LAMBDA VAC ANG', '<f8'), ('SPECTRUM', 'S4'), ('TT', 'S2'), ('TERM', 'S6'), ('J J', 'S5'), ('LEVEL ENERGY CM 1', 'S18')])