LIGHTNING_INPUT#

Name#

LIGHTNING_INPUT

Purpose#

Reads in the SED data that is to be fit by Lightning from a FITS file. The input fluxes are converted to luminosities using the user supplied redshift or luminosity distance. These luminosities are then saved to a .sav file for each SED to be fit by Lightning.

Calling Sequence#

lightning_input, input_file_fits [, cosmology = , /xray_emission, xray_unit = , xray_unc = ]

Input#

input_file_fitsstring scalar

The name (including path) to the FITS file containing the SED fluxes and distances (or redshifts) in a data table. The table must be in the first extension. (See FITS Table Format for full details, required contents, and format of the data table.)

Optional Inputs#

cosmologystructure

A structure containing the cosmology parameters H0, OMEGA_M, LAMBDA0, Q0, and K in individual tags. (Default = {H0: 70, OMEGA_M: 0.3, LAMBDA0: 0.7, Q0: -0.55, K: 0})

xray_emissionflag

If set, Lightning will search for and load the additional data products necessary to fit an X-ray emission model.

xray_unitstring scalar

The type of X-ray data to use in fitting. Current options are 'COUNTS' and 'FLUX'. (Default = 'COUNTS')

xray_uncstring scalar

The errors to assume if using X-ray count data. Current options are 'SQRT', 'GEHRELS', and 'USER'. (Default = 'GEHRELS')

Output#

A save file (<input_file_dir>/lightning_output/input_sav_files/lightning_input_<sed_id>.sav) for each SED that contains the data converted to luminosities. The data for each SED are stored in a structure with the following format:

TAG

TYPE

DESCRIPTION

SED_ID

string

Unique SED identifier

LNU_OBS

double(Nfilters)

Luminosities of the SED for each set of filters in terms of \(L_\nu\) \([\rm{L_{\odot}\ Hz^{-1}}]\)

LNU_UNC

double(Nfilters)

Uncertainties associated with the luminosities \([\rm{L_{\odot}\ Hz^{-1}}]\)

FILTER_LABELS

string(Nfilters)

Names of the filters associated with each luminosity

REDSHIFT

double

Redshift of the SED (if LUMIN_DIST was specified this is set to 0)

LUMIN_DIST

double

Luminosity distance of the SED as input or converted from the redshift \([\rm{Mpc}]\)

XRAY_LNU_OBS [1]

double(Nxray)

X-ray luminosities for each bandpass in terms of \(L_\nu\) \([\rm{L_{\odot}\ Hz^{-1}}]\)

XRAY_LNU_UNC [1]

double(Nxray)

Uncertainties associated with the X-ray luminosities \([\rm{L_{\odot}\ Hz^{-1}}]\)

XRAY_BANDPASS [1] [2]

double(2, Nxray)

Bandpasses of X-ray observations: first column contains the lower energy bound, second column contains the upper. \([\rm{keV}]\)

XRAY_EXPOSURE [2]

double(Nxray)

Exposure times of X-ray observations, one per band \([\rm{s}]\)

NET_COUNTS [2]

double(Nxray)

Net counts in each X-ray band \([\rm{counts}]\)

NET_COUNTS_UNC [2]

double(Nxray)

User-supplied uncertainty in net counts, if any \([\rm{counts}]\)

GALACTIC_NH [1] [2]

double

Galactic (i.e., Milky Way) HI column density along the line of sight \([10^{20}\ \rm{cm}^{-2}]\)

ARF_E_LO [2]

double(Nchannels)

Lower energy bounds of each channel in the ARF \([\rm{keV}]\)

ARF_E_HI [2]

double(Nchannels)

Upper energy bounds of each channel in the ARF \([\rm{keV}]\)

ARF_SPECRESP [2]

double(Nchannels)

Spectral response of the ARF at each channel \([\rm{cm^2}]\)

Modification History#

  • 2022/03/23: Created (Keith Doore)

  • 2022/04/25: Updated to allow for Xray ARF file path (Keith Doore)

  • 2022/04/28: Added unique SED_ID enforcement (Keith Doore)

  • 2022/05/18: Added optional cosmology input to allow for unique cosmologies in lumdist (Keith Doore)

  • 2022/05/18: Added check to make sure xray files existed (Keith Doore)

  • 2022/05/19: Replace n_elements(where()) statements in logicals with total() (Keith Doore)

  • 2022/06/27: Removed missing data from SED before saving to file (Keith Doore)

  • 2022/06/27: Fixed issue where xray_spec/arf file strings need to be trimmed of padded blanks (Keith Doore)

  • 2022/08/01: Added /silent to mrdfits (Keith Doore)

  • 2022/08/02: Undid removal of missing data from SED before saving to file to make post-processing simpler (Keith Doore)

  • 2022/08/02: Added ability to use redshift if lumin_dist is 0 for some SEDs (Keith Doore)

  • 2022/08/02: Added check to require both XRAY_SPEC_FILE and XRAY_ARF_FILE tags if including X-ray data (Keith Doore)

  • 2022/08/09: Added GALACTIC_NH as input for xray emission (Keith Doore)

  • 2022/08/10: Fixed bug with redshift distance being computed even with no redshifts (Keith Doore)

  • 2022/09/01: Added handling for user-supplied X-ray count uncertainties (Erik B. Monson)

  • 2022/09/14: Updated to allow fitting with X-ray fluxes (Erik B. Monson)

  • 2022/09/15: Updated documentation (Keith Doore)

  • 2022/10/24: Allowed for negative flux inputs (Keith Doore)