AtomNeb: IDL Library for Atomic Data of Ionized Nebulae

Spectra emitted from ionized nebulae typically contain collisionally excited and recombination lines, which can be used to trace physical conditions and chemical abundances of the interstellar medium in our Galaxy and other galaxies. "AtomNeb" is a database containing atomic data stored in the Flexible Image Transport System (FITS) file format, including the data for collisionally excited and recombination lines often observed in nebular astrophysics. The AtomNeb interface library is equipped with several application programming interface (API) functions developed in the Interactive Data Language (IDL), also usable in the GNU Data Language (GDL), and in the high-level, general-purpose programming language Python. The IDL library relies on the FITS file-related IDL procedures from the IDL Astronomy User's library, while the Python package depends on the Python packages Astropy and NumPy. The AtomNeb IDL library and the corresponding Python package, in conjunction with the "proEQUIB" IDL library and "pyEQUIB" Python package, respectively, can be used to perform plasma diagnostics and abundance analysis of emission lines from ionized gaseous nebulae.