Planning

Principles

• All pull requests will be reviewed by at least one (and hopefully) two of the repository maintainers (currently Karl Gordon, JD Smith, and Els Peteers).
• IDL PAHFIT version are v1.x. Python PAHFIT versions are v2.x.
• PAHFIT v2.0 publication should be referenced when using the python PAHFIT code at a minimum.

Name

• PAHFIT
• other names were considered, but PAHFIT deemed the best

Features

• Science model
  • Dust features: PAHs, Silicates, Ices, Dust attenuation
  • Gas Features: Ionized, Atomic, Molecular (H_2)
  • includes intrinsic widths/profiles
• Instrument model
  • spectral resolutions/profiles
    • allow for variations with wavelength
• Fitting
  • use different fitters
    • chisqr minimum optimizers
    • MCMC optimizers (e.g., emcee)
    • grid search?
  • constraint packs
    • vary with data and source type
    • at least: min/max for feature properties including ratios between features
    • ideal: full prior specifications for more complicated than min/max flat constraints

version 1.0-1.4 (IDL)

• http://tir.astro.utoledo.edu/jdsmith/research/pahfit.php

version 2.0 (python)

• Updates:
  • Translation of IDL version to Python (with bugfixes)
  • Update PAHFIT to use astropy.modeling framework
  • Set-up the modular approach for future additions
• Use different fitters
• Applicable to: Spitzer data
• Object focus: galaxy spectra
• Lead by: Karl/JD
• Developed fully open
  • Official version released when it works
  • Development versions available, but not advertised till released
• Possible training sets / tests (IDL vs Python):
  • Spitzer data on galaxies (low and high R): Karin?
  • Spitzer data on galaxies of all types (low R): Henrik?
  • Spitzer data on HII regions in M33/M83 (low and high R): Els/Alexandros
• Timeline: Spring 2019
• Publication:
  • "lightweight" publication with all contributors at that point
  • could focus on IDL vs python testing and introduction python package
  • possible refereed journals: JOSS (https://joss.theoj.org/​) or PASP

version 2.1

• Updates:
  • version 2.0 extended to include Akari data (shorter wavelengths)
  • Include ices
  • Updated attenuation model
• Applicable to: Akari+Spitzer data
• Object focus: galaxy spectra
• Lead by: Thomas Lai and JD
• Not advertised until paper released
• Training Set / Test:
  • Akari + Spitzer data on galaxies: Thomas & JD
  • Spitzer data on galaxies (including ices): Henrik?
• Timeline: Winter 2019
• Publication: Paper 2 of Thomas’ PhD

version 2.2

• Updates:
  • Modify so it’s applicable to ISO-SWS wavelength and resolution
  • Add continuum options
• Applicable to: ISO-SWS
• Object focus: PDR spectra (1st priority) & circumstellar spectra (2nd priority)
• Lead by: Els/Alexandros
• Developed fully open
  • Official version released when it works
  • Development versions available, but not advertised until released
• Training Set / Test:
  • ISO-SWS data of HII Regions, PDRs, evolved stars(?) & 3 galaxies: Els/Alexandros
• Timeline: Fall 2019
• Publication: ?

version 2.3

• Updates:
  • Make it suitable for real JWST NIRSpec and MIRI data
• Applicable to: JWST NIRSpec and MIRI spectroscopy
• Object focus: PDR and galaxy spectra
• Lead by: All
• Developed fully open
  • Official version released when it works
  • Development versions available, but not advertised till released
• Training Set / Test:
  • Simulated JWST data
  • ERS(/GTO?) JWST data
• Timeline: Launch + 1 year?
• Publication: with ERS team/data, others for galaxy datasets

Training sets

• it would be good to have publicly available sets of data
• use them as part of jypter notebooks, tutorials, automated testing, etc.
• Spitzer
  • Galaxies: JD/Henrick?
  • MW objects: ??
• Spitzer+AKARI
  • Thomas: ??
• ISO
  • MW objects: Els?
  • Galaxies: Henrick?
• JWST
  • ERS PDR program: Karl/Els/Alexandros/...