pypeit.spectrographs.vlt_fors module

Module for VLT FORS (1 and 2)

class pypeit.spectrographs.vlt_fors.VLTFORS2Spectrograph[source]

Bases: VLTFORSSpectrograph

Child to handle VLT/FORS2 specific code

camera = 'FORS2'

Name of the spectrograph camera or arm. This is used by specdb, so use that naming convention

comment = '300I, 300V gratings. Supports LSS and MOS mode only.'

A brief comment or description regarding PypeIt usage with this spectrograph.

config_independent_frames()[source]

Define frame types that are independent of the fully defined instrument configuration.

This method returns a dictionary where the keys of the dictionary are the list of configuration-independent frame types. The value of each dictionary element can be set to one or more metadata keys that can be used to assign each frame type to a given configuration group. See set_configurations() and how it interprets the dictionary values, which can be None.

Returns:

Dictionary where the keys are the frame types that are configuration-independent and the values are the metadata keywords that can be used to assign the frames to a configuration group.

Return type:

dict

config_specific_par(scifile, inp_par=None)[source]

Modify the PypeIt parameters to hard-wired values used for specific instrument configurations.

Parameters:
  • scifile (str) – File to use when determining the configuration and how to adjust the input parameters.

  • inp_par (ParSet, optional) – Parameter set used for the full run of PypeIt. If None, use default_pypeit_par().

Returns:

The PypeIt parameter set adjusted for configuration specific parameter values.

Return type:

ParSet

configuration_keys()[source]

Return the metadata keys that define a unique instrument configuration.

This list is used by PypeItMetaData to identify the unique configurations among the list of frames read for a given reduction.

Returns:

List of keywords of data pulled from file headers and used to constuct the PypeItMetaData object.

Return type:

list

get_detector_par(det, hdu=None)[source]

Return metadata for the selected detector.

Parameters:
  • det (int) – 1-indexed detector number. ESO writes each of the two detectors to separate files. When hdu is provided, this is ignored and instead the chip is determined by the header parameter “EXTNAME”. If hdu is None (for automatically generated documentation only), this can be used to set the chip (1 or 2) that is returned.

  • hdu (astropy.io.fits.HDUList, optional) – The open fits file with the raw image of interest. If not provided, frame-dependent parameters are set to a default.

Returns:

Object with the detector metadata.

Return type:

DetectorContainer

header_name = 'FORS2'

Name of the spectrograph camera or arm from the Header. Usually the INSTRUME card.

name = 'vlt_fors2'

The name of the spectrograph. See Spectrographs for the currently supported spectrographs.

parse_dither_pattern(file_list, ext=None)[source]

Parse headers from a file list to determine the dither pattern.

Parameters:
  • strings) (file_list (list of) – List of files for which dither pattern is desired

  • (int (ext) – Extension containing the relevant header for these files. Default=None. If None, code uses self.primary_hdrext

  • optional) – Extension containing the relevant header for these files. Default=None. If None, code uses self.primary_hdrext

Returns:

  • dither_pattern, dither_id, offset_arcsec

  • dither_pattern (str numpy.ndarray) – Array of dither pattern names

  • dither_id (str numpy.ndarray) – Array of dither pattern IDs

  • offset_arc (float numpy.ndarray) – Array of dither pattern offsets

raw_header_cards()[source]

Return additional raw header cards to be propagated in downstream output files for configuration identification.

The list of raw data FITS keywords should be those used to populate the configuration_keys() or are used in config_specific_par() for a particular spectrograph, if different from the name of the PypeIt metadata keyword.

This list is used by subheader_for_spec() to include additional FITS keywords in downstream output files.

Returns:

List of keywords from the raw data files that should be propagated in output files.

Return type:

list

supported = True

Flag that PypeIt code base has been sufficiently tested with data from this spectrograph that it is officially supported by the development team.

class pypeit.spectrographs.vlt_fors.VLTFORSSpectrograph[source]

Bases: Spectrograph

Child of Spectrograph to handle VLT/FORS specific code Parent for FORS1 and FORS2

check_frame_type(ftype, fitstbl, exprng=None)[source]

Check for frames of the provided type.

Parameters:
Returns:

Boolean array with the flags selecting the exposures in fitstbl that are ftype type frames.

Return type:

numpy.ndarray

compound_meta(headarr, meta_key)[source]

Methods to generate metadata requiring interpretation of the header data, instead of simply reading the value of a header card.

Parameters:
Returns:

Metadata value read from the header(s).

Return type:

object

configuration_keys()[source]

Return the metadata keys that define a unique instrument configuration.

This list is used by PypeItMetaData to identify the unique configurations among the list of frames read for a given reduction.

Returns:

List of keywords of data pulled from file headers and used to constuct the PypeItMetaData object.

Return type:

list

classmethod default_pypeit_par()[source]

Return the default parameters to use for this instrument.

Returns:

Parameters required by all of PypeIt methods.

Return type:

PypeItPar

init_meta()[source]

Define how metadata are derived from the spectrograph files.

That is, this associates the PypeIt-specific metadata keywords with the instrument-specific header cards using meta.

ndet = 1

Number of detectors for this instrument.

telescope = Parameter     Value                Default  Type        Callable ---------------------------------------------------------------- name          VLT                  KECK     str         False    longitude     -70.40498688000002   None     int, float  False    latitude      -24.627439409999997  None     int, float  False    elevation     2668.999999999649    None     int, float  False    fratio        None                 None     int, float  False    diameter      8.2                  None     int, float  False    eff_aperture  51.2                 None     int, float  False   

Instance of TelescopePar providing telescope-specific metadata.

url = 'https://www.eso.org/sci/facilities/paranal/instruments/fors.html'

Reference url