1 Background¶
1.1 Purpose¶
Pypahdb is used to characterize emission from one of the most prevalent types of organic molecules in space, namely polycyclic aromatic hydrocarbons (PAHs). It leverages the detailed studies of organic molecules done at the NASA Ames Research Center. Pypahdb is a streamlined Python version of the NASA Ames PAH IR Spectroscopic Database’s (PAHdb; www.astrochemistry.org/pahdb/) suite of IDL and Python tools. PAHdb has been extensively used to analyze and interpret the PAH signature from a plethora of emission sources, ranging from solar-system objects to entire galaxies. Pypahdb decomposes astronomical PAH emission spectra into contributing PAH sub-classes in terms of charge and size using a database-fitting technique. The inputs for the fit are spectra constructed using the spectroscopic libraries of PAHdb and take into account the detailed photo-physics of the PAH excitation/emission process.
1.2 Features¶
The purpose of pypahdb is to derive astronomical parameters directly from JWST observations, but the tool is not limited to JWST observations alone. Pypahdb is the light version of a full suite of Python software tools[1] that is an analog of the off-line IDL tools[2]. A feature comparison is presented in the table below. Pypahdb will enable PAH experts and non-experts alike to analyze and interpret astronomical PAH emission spectra.
Pypahdb |
IDL/Python Tools |
|
|---|---|---|
Included molecules. |
Fixed |
User defined |
Excitation energy |
Fixed |
User defined |
Emission profile |
Fixed |
Selectable |
FWHM |
Fixed |
User defined |
Band redshift |
Fixed |
User defined |
Emission model |
Fixed |
Selectable |
NNLS |
✓ |
✓ |
NNLC |
✓ |
|
Class breakdown |
✓ |
✓ |
Parallelization |
✓ |
✓ |
Uncertainties |
✓ |
1.3 Academic references¶
You are kindly asked to consider the following references for citation when using pypahdb:
Shannon, M.J., Boersma, C., “ORGANIC MOLECULES IN SPACE: INSIGHTS FROM THE NASA AMES MOLECULAR DATABASE IN THE ERA OF THE JAMES WEBB SPACE TELESCOPE”, 2018, SciPy, 99 https://doi.org/10.25080/majora-4af1f417-00f
C.W. Bauschlicher, Jr., A. Ricca, C. Boersma, L.J. Allamandola, “THE NASA AMES PAH IR SPECTROSCOPIC DATABASE: COMPUTATIONAL VERSION 3.00 WITH UPDATED CONTENT AND THE INTRODUCTION OF MULTIPLE SCALING FACTORS”, The Astrophysical Journal Supplement Series, 234, 32, 2018, https://doi.org/10.3847/1538-4365/aaa019
C. Boersma, C.W. Bauschlicher, Jr., A. Ricca, A.L. Mattioda, J. Cami, E. Peeters, F. Sánchez de Armas, G. Puerta Saborido, D.M. Hudgins, and L.J. Allamandola, “THE NASA AMES PAH IR SPECTROSCOPIC DATABASE VERSION 2.00: UPDATED CONTENT, WEBSITE AND ON/OFFLINE TOOLS”, The Astrophysical Journal Supplement Series, 211, 8, 2014, https://doi.org/10.1088/0067-0049/211/1/8
C.W. Bauschlicher, Jr., C. Boersma, A. Ricca, A.L. Mattioda, J. Cami, E. Peeters, F. Sánchez de Armas, G. Puerta Saborido, D.M. Hudgins, and L.J. Allamandola, “THE NASA AMES PAH IR SPECTROSCOPIC DATABASE: THE COMPUTED SPECTRA”, The Astrophysical Journal Supplement Series, 189, 341, 2010, https://doi.org/10.1088/0067-0049/189/2/341
Mattioda, A. L., Hudgins, D. M., Boersma, C., Ricca, A., Peeters, E., Cami, J., Sánchez de Armas, F., Puerta Saborido, G., Bauschlicher, C. W., J., and Allamandola, L. J. “THE NASA AMES PAH IR SPECTROSCOPIC DATABASE: THE LABORATORY SPECTRA”, The Astrophysical Journal Supplement Series, 251, 22, 2020, https://doi.org/10.3847/1538-4365/abc2c8