2.5. utils.specutils_stis package

2.5.1. get_association_indices

utils.specutils_stis.get_association_indices.get_association_indices(associations)

Given a list of associations, determines the indices that will be plotted. If n_associations > 3, this is the first, middle, and last associations, otherwise it’s all of them.

Parameters:

associations (list) – All of the associations for this STIS spectrum.

Returns:

list – The indices of the list that will be plotted.

2.5.2. plotspec

utils.specutils_stis.plotspec(stis_spectrum, association_indices, stitched_spectra, output_type, output_file, flux_scale_factor, fluxerr_scale_factor, plot_metrics, dpi_val=96.0, output_size=1024, debug=False, full_ylabels=False, optimize=True)

Accepts a STIS1DSpectrum object from the READSPEC function and produces preview plots.

Parameters:

  • stis_spectrum (STIS1DSpectrum) – STIS spectrum as returned by READSPEC.

  • association_indices (list) – The indices of the original list of associations for this spectrum that will be plotted. Used in the informational plot title, e.g., Association <x> of <y>., where <x> is the association index and <y> is the total number of associations in this spectrum.

  • stitched_spectra (list) – List of order-stitched spectra for each association, as created in utils.specutils.stitch_components().

  • output_type (str) – What kind of output to make?

  • output_file (str) – Name of output file (including full path).

  • flux_scale_factor (float) – Max. allowed ratio between the flux and a median flux value, used in edge trimming. Default = 10.

  • fluxerr_scale_factor (float) – Max. allowed ratio between the flux uncertainty and a median flux uncertainty value, used in edge trimming. Default = 5.

  • plot_metrics (list) – Collection of plot metrics (flux statistics, axis ranges, etc.) to use when making the plots. These are computed using utils.specutils.calc_plot_metrics().

  • dpi_val (float) – The DPI value of your device’s monitor. Affects the size of the output plots. Default = 96. (applicable to most modern monitors).

  • output_size – Size of plot in pixels (plots are square in dimensions). Defaults to 1024.

  • output_size – int

  • debug (bool) – Should the output plots include debugging information (color-coded data points based on rejection criteria, shaded exclude regions)? Default = False.

  • full_ylabels (bool) – Should the y-labels contain the full values (including the power of 10 in scientific notation)? Default = False.

  • optimize (bool) – If set to True, will use a slightly optimized version of determining the plot covering fraction.

Raises:

OSError, utils.specutils.SpecUtilsError

Note

This function assumes a screen resolution of 96 DPI in order to generate plots of the desired sizes. This is because matplotlib works in units of inches and DPI rather than pixels.

2.5.3. readspec

utils.specutils_stis.readspec(input_file)

Reads in a STIS spectrum FITS file (x1d, sx1) and returns the wavelengths, fluxes, and flux uncertainties for the two (FUV segments) or three (NUV stripes).

Parameters:

input_file (str) – Name of input FITS file.

Returns:

STIS1DSpectrum – The spectroscopic data (wavelength, flux, flux error, etc):

2.5.4. stis1dspectrum

class utils.specutils_stis.stis1dspectrum.STIS1DSpectrum(association_spectra, orig_file=None)

Bases: object

Defines a STIS 1D spectrum (either “x1d” extracted or “sx1” summed extracted), including wavelegnth, flux, and flux errors. A STIS 1D spectrum object consists of N associations. If the file is an association, then N > 1, otherwise N = 1. Each of these N associations can contain M orders. If the association is an Echelle spectrum, then 24 < M < 70, depending on instrument configuration, otherwise M = 1. Each of these M orders contain typical spectral data (wavelengths, fluxes, etc.), stored as STISOrderSpectrum objects. The final data structure is then <STIS1DSpectrum>.associations[n].order[m].wavelengths (or .fluxes, .fluxerrs, etc.).

Raises:

ValueError

class utils.specutils_stis.stis1dspectrum.STISExposureSpectrum(order_spectra)

Bases: object

Defines a STIS exposure spectrum, which consists of “M” STISOrderSpectrum objects.

class utils.specutils_stis.stis1dspectrum.STISOrderSpectrum(nelem=None, wavelengths=None, fluxes=None, fluxerrs=None, dqs=None)

Bases: object

Defines a STIS order spectrum, including wavelength, flux, flux errors, and data quality flags, which are stored as numpy arrays. A scalar int property provides the number of elements in this segment.