.. |ang| unicode:: U+212B .. include:: include/links.rst .. _spectralindices: Spectral Indices ================ The spectral indices to be measured by the DAP are divided into two groups: (1) absorption-line indices that measure the equivalent width of an absorption feature and (2) bandhead or color indices that measure the ratio of fluxes is in two passbands. Both sets of indices are measured using :class:`~mangadap.proc.spectralindices.SpectralIndices`; see :ref:`spectral-index-measurements`. ---- .. _spectralindices-absorption: Absorption-line Indices ----------------------- Calculation ~~~~~~~~~~~ .. include:: include/absindices.rst See :class:`~mangadap.proc.spectralindices.AbsorptionLineIndices`. Index Parameters ~~~~~~~~~~~~~~~~ The table below provides a compilation of absorption-line indices. Recent survey-level runs of the DAP have included all of these measurements. +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Name | Main Passband (|ang|) | Blue Sideband (|ang|) | Red Sideband (|ang|) | Frame | Units | Ref | +===========+=======================+=======================+======================+=======+=======+======+ | CN1 | 4142.125 -- 4177.125 | 4080.125 -- 4117.625 | 4244.125 -- 4284.125 | air | mag | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | CN2 | 4142.125 -- 4177.125 | 4083.875 -- 4096.375 | 4244.125 -- 4284.125 | air | mag | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Ca4227 | 4222.250 -- 4234.750 | 4211.000 -- 4219.750 | 4241.000 -- 4251.000 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | G4300 | 4281.375 -- 4316.375 | 4266.375 -- 4282.625 | 4318.875 -- 4335.125 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe4383 | 4369.125 -- 4420.375 | 4359.125 -- 4370.375 | 4442.875 -- 4455.375 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Ca4455 | 4452.125 -- 4474.625 | 4445.875 -- 4454.625 | 4477.125 -- 4492.125 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe4531 | 4514.250 -- 4559.250 | 4504.250 -- 4514.250 | 4560.500 -- 4579.250 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | C24668 | 4634.000 -- 4720.250 | 4611.500 -- 4630.250 | 4742.750 -- 4756.500 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Hb | 4847.875 -- 4876.625 | 4827.875 -- 4847.875 | 4876.625 -- 4891.625 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe5015 | 4977.750 -- 5054.000 | 4946.500 -- 4977.750 | 5054.000 -- 5065.250 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Mg1 | 5069.125 -- 5134.125 | 4895.125 -- 4957.625 | 5301.125 -- 5366.125 | air | mag | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Mg2 | 5154.125 -- 5196.625 | 4895.125 -- 4957.625 | 5301.125 -- 5366.125 | air | mag | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Mgb | 5160.125 -- 5192.625 | 5142.625 -- 5161.375 | 5191.375 -- 5206.375 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe5270 | 5245.650 -- 5285.650 | 5233.150 -- 5248.150 | 5285.650 -- 5318.150 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe5335 | 5312.125 -- 5352.125 | 5304.625 -- 5315.875 | 5353.375 -- 5363.375 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe5406 | 5387.500 -- 5415.000 | 5376.250 -- 5387.500 | 5415.000 -- 5425.000 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe5709 | 5696.625 -- 5720.375 | 5672.875 -- 5696.625 | 5722.875 -- 5736.625 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Fe5782 | 5776.625 -- 5796.625 | 5765.375 -- 5775.375 | 5797.875 -- 5811.625 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | NaD | 5876.875 -- 5909.375 | 5860.625 -- 5875.625 | 5922.125 -- 5948.125 | air | |ang| | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | TiO1 | 5936.625 -- 5994.125 | 5816.625 -- 5849.125 | 6038.625 -- 6103.625 | air | mag | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | TiO2 | 6189.625 -- 6272.125 | 6066.625 -- 6141.625 | 6372.625 -- 6415.125 | air | mag | [1]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | HDeltaA | 4083.500 -- 4122.250 | 4041.600 -- 4079.750 | 4128.500 -- 4161.000 | air | |ang| | [2]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | HGammaA | 4319.750 -- 4363.500 | 4283.500 -- 4319.750 | 4367.250 -- 4419.750 | air | |ang| | [2]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | HDeltaF | 4091.000 -- 4112.250 | 4057.250 -- 4088.500 | 4114.750 -- 4137.250 | air | |ang| | [2]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | HGammaF | 4331.250 -- 4352.250 | 4283.500 -- 4319.750 | 4354.750 -- 4384.750 | air | |ang| | [2]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | CaHK | 3899.5 -- 4003.5 | 3806.5 -- 3833.8 | 4020.7 -- 4052.4 | air | |ang| | [3]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | CaII1 | 8484.0 -- 8513.0 | 8474.0 -- 8484.0 | 8563.0 -- 8577.0 | air | |ang| | [4]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | CaII2 | 8522.0 -- 8562.0 | 8474.0 -- 8484.0 | 8563.0 -- 8577.0 | air | |ang| | [4]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | CaII3 | 8642.0 -- 8682.0 | 8619.0 -- 8642.0 | 8700.0 -- 8725.0 | air | |ang| | [4]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Pa17 | 8461.0 -- 8474.0 | 8474.0 -- 8484.0 | 8563.0 -- 8577.0 | air | |ang| | [4]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Pa14 | 8577.0 -- 8619.0 | 8563.0 -- 8577.0 | 8619.0 -- 8642.0 | air | |ang| | [4]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | Pa12 | 8730.0 -- 8772.0 | 8700.0 -- 8725.0 | 8776.0 -- 8792.0 | air | |ang| | [4]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | MgICvD | 5165.0 -- 5220.0 | 5125.0 -- 5165.0 | 5220.0 -- 5260.0 | vac | |ang| | [5]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | NaICvD | 8177.0 -- 8205.0 | 8170.0 -- 8177.0 | 8205.0 -- 8215.0 | vac | |ang| | [5]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | MgIIR | 8801.9 -- 8816.9 | 8777.4 -- 8789.4 | 8847.4 -- 8857.4 | vac | |ang| | [5]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | FeHCvD | 9905.0 -- 9935.0 | 9855.0 -- 9880.0 | 9940.0 -- 9970.0 | vac | |ang| | [5]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | NaI | 8168.500 -- 8234.125 | 8150.000 -- 8168.400 | 8235.250 -- 8250.000 | air | |ang| | [6]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | bTiO | 4758.500 -- 4800.000 | 4742.750 -- 4756.500 | 4827.875 -- 4847.875 | air | mag | [7]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | aTiO | 5445.000 -- 5600.000 | 5420.000 -- 5442.000 | 5630.000 -- 5655.000 | air | mag | [7]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | CaH1 | 6357.500 -- 6401.750 | 6342.125 -- 6356.500 | 6408.500 -- 6429.750 | air | mag | [7]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | CaH2 | 6775.000 -- 6900.000 | 6510.000 -- 6539.250 | 7017.000 -- 7064.000 | air | mag | [7]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | NaISDSS | 8180.0 -- 8200.0 | 8143.0 -- 8153.0 | 8233.0 -- 8244.0 | air | |ang| | [8]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ | TiO2SDSS | 6189.625 -- 6272.125 | 6066.625 -- 6141.625 | 6422.0 -- 6455.0 | air | mag | [8]_ | +-----------+-----------------------+-----------------------+----------------------+-------+-------+------+ Input Data Format ~~~~~~~~~~~~~~~~~ The parameters that define the absorption-line-index calculations are provided via the :class:`~mangadap.par.absorptionindexdb.AbsorptionIndexDB` object, which is built using an `SDSS-style parameter file`_. The core level class that calculates the raw absorption-line indices is :class:`~mangadap.proc.spectralindices.AbsorptionLineIndices`. The columns of the parameter file are: +---------------+-----------+-----------------------------------------------------------------------+ | Parameter | Format | Description | +===============+===========+=======================================================================+ | ``index`` | int | Unique integer identifier of the absorption-line index. **Must** be | | | | unique. | +---------------+-----------+-----------------------------------------------------------------------+ | ``name`` | str | Name of the index. **Must** be unique. | +---------------+-----------+-----------------------------------------------------------------------+ | ``primary`` | float[2] | A two-element vector with the starting and ending wavelength for the | | | | primary passband surrounding the absorption feature(s). | +---------------+-----------+-----------------------------------------------------------------------+ | ``blueside`` | float[2] | A two-element vector with the starting and ending wavelength for a | | | | passband to the blue of the primary band. | +---------------+-----------+-----------------------------------------------------------------------+ | ``redside`` | float[2] | A two-element vector with the starting and ending wavelength for a | | | | passband to the red of the primary band. | +---------------+-----------+-----------------------------------------------------------------------+ | ``waveref`` | str | The reference frame of the wavelengths; must be either 'air' for air | | | | or 'vac' for vacuum. | +---------------+-----------+-----------------------------------------------------------------------+ | ``units`` | str | Units for the absorption index, which must be either 'ang' or 'mag'. | +---------------+-----------+-----------------------------------------------------------------------+ | ``component`` | int | **Never used**: Binary flag (0-false,1-true) that the index is a | | | | component of a composite index. If true (1), all components with the | | | | same NAME are added together to form the composite index. | +---------------+-----------+-----------------------------------------------------------------------+ and an example file might look like this: .. code-block:: c typedef struct { int index; char name[9]; double primary[2]; double blueside[2]; double redside[2]; char waveref[3]; char units[3]; int component; } DAPABI; DAPABI 1 CN1 { 4142.125 4177.125 } { 4080.125 4117.625 } { 4244.125 4284.125 } air mag 0 DAPABI 2 CN2 { 4142.125 4177.125 } { 4083.875 4096.375 } { 4244.125 4284.125 } air mag 0 Note that the functionality implied by the ``component`` parameter has been a notional future development for the module, but has never been implemented. However, unfortunately, it's still a required element of the database file. Changing the absorption-line index parameters ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The absorption-line indices are measured by :class:`~mangadap.proc.spectralindices.SpectralIndices`; see :ref:`spectral-index-measurements`. A set of parameter files that define a list of absorption-line index sets are provided with the DAP source distribution and located at ``$MANGADAP_DIR/mangadap/data/absorption_indices``. The database you wish to use is selected by the ``absindex`` parameter in the relevant parameter block of the :ref:`plan` file. The keyword is simply the capitalized name of the file without the ".par" extension. For example, to use the `extindx.par `__ database, the plan file would include .. code-block:: toml [default.indices] absindex = 'EXTINDX' To provide a user-defined database, simply replace the ``absindex`` keyword with the name of the local file defining the database (in the format given above). For example, .. code-block:: toml [default.indices] absindex = '/path/to/my/local/file/my_abs_database.par' ---- .. _spectralindices-bandhead: Bandhead or Color Indices ------------------------- Calculation ~~~~~~~~~~~ .. include:: include/bhdindices.rst See :class:`~mangadap.proc.spectralindices.BandheadIndices`. Index Parameters ~~~~~~~~~~~~~~~~ The table below provides a compilation of bandhead and color indices. Recent survey-level runs of the DAP have included all of these measurements. +--------+-----------------------+----------------------+-------+-------------------+-------+-------+ | Name | Blue Sideband (|ang|) | Red Sideband (|ang|) | Frame | Integrand | Order | Ref | +========+=======================+======================+=======+===================+=======+=======+ | D4000 | 3750 -- 3950 | 4050 -- 4250 | air | :math:`F_\nu` | R/B | [9]_ | +--------+-----------------------+----------------------+-------+-------------------+-------+-------+ | Dn4000 | 3850 -- 3950 | 4000 -- 4100 | air | :math:`F_\nu` | R/B | [10]_ | +--------+-----------------------+----------------------+-------+-------------------+-------+-------+ | TiOCvD | 8835 -- 8855 | 8870 -- 8890 | vac | :math:`F_\lambda` | B/R | [5]_ | +--------+-----------------------+----------------------+-------+-------------------+-------+-------+ Input Data Format ~~~~~~~~~~~~~~~~~ The parameters that define the bandhead index calculations are provided via the :class:`~mangadap.par.bandheadindexdb.BandheadIndexDB` object, which is built using an `SDSS-style parameter file`_. The core level class that calculates the raw bandhead indices is :class:`~mangadap.proc.spectralindices.BandheadIndices`. The columns of the parameter file are: +---------------+-----------+-----------------------------------------------------------------------+ | Parameter | Format | Description | +===============+===========+=======================================================================+ | ``index`` | int | Unique integer identifier of the absorption-line index. **Must** be | | | | unique. | +---------------+-----------+-----------------------------------------------------------------------+ | ``name`` | str | Name of the index. **Must** be unique. | +---------------+-----------+-----------------------------------------------------------------------+ | ``blueside`` | float[2] | A two-element vector with the starting and ending wavelength for a | | | | passband to the blue of the primary band. | +---------------+-----------+-----------------------------------------------------------------------+ | ``redside`` | float[2] | A two-element vector with the starting and ending wavelength for a | | | | passband to the red of the primary band. | +---------------+-----------+-----------------------------------------------------------------------+ | ``waveref`` | str | The reference frame of the wavelengths; must be either 'air' for air | | | | or 'vac' for vacuum. | +---------------+-----------+-----------------------------------------------------------------------+ | ``integrand`` | str | Integrand within the passband for the construction of the index, | | | | which must be either 'fnu' or 'flambda'. | +---------------+-----------+-----------------------------------------------------------------------+ | ``order`` | str | Define the order to use when constructing the index. The options are | | | | either a ratio of red-to-blue or blue-to-red, which are respectively | | | | selected using 'r_b' or 'b_r'. | +---------------+-----------+-----------------------------------------------------------------------+ and an example file might look like this: .. code-block:: c typedef struct { int index; char name[9]; double blueside[2]; double redside[2]; char waveref[3]; char integrand[7]; char order[3]; } DAPBHI; DAPBHI 1 D4000 { 3750.000 3950.000 } { 4050.000 4250.000 } air fnu r_b DAPBHI 2 Dn4000 { 3850.000 3950.000 } { 4000.000 4100.000 } air fnu r_b DAPBHI 3 TiOCvD { 8835.000 8855.000 } { 8870.000 8890.000 } vac flambda b_r Changing the bandhead index parameters ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The bandhead and color indices are measured by :class:`~mangadap.proc.spectralindices.SpectralIndices`; see :ref:`spectral-index-measurements`. A set of parameter files that define a list of bandhead index sets are provided with the DAP source distribution and located at ``$MANGADAP_DIR/mangadap/data/bandhead_indices``. The database you wish to use is selected by the ``bandhead`` parameter in the relevant parameter block of the :ref:`plan` file. The keyword is simply the capitalized name of the file without the ".par" extension. For example, to use the `bhbasic.par `__ database, the plan file would include .. code-block:: toml [default.indices] bandhead = 'BHBASIC' To provide a user-defined database, simply replace the ``bandhead`` keyword with the name of the local file defining the database (in the format given above). For example, .. code-block:: toml [default.indices] bandhead = '/path/to/my/local/file/my_bhd_database.par' ---- .. [1] `Trager et al. (1998, ApJS, 116, 1) `_ .. [2] `Worthey & Ottaviani (1997, ApJS, 111, 377) `_ .. [3] `Serven et al. (2005, ApJ, 627, 754) `_ .. [4] `Cenarro et al. (2001, MNRAS, 326, 959) `_; however, note that each index is considered seperately, which is *not* the definition provided in Table 4 of their paper. .. [5] `Conroy & van Dokkum (2012, ApJ, 747, 69) `_ .. [6] `Spiniello et al. (2012, ApJL, 753, 32) `_ .. [7] `Spiniello et al. (2014, MNRAS, 438, 1483) `_ .. [8] `La Barbera et al. (2013, MNRAS, 433, 3017) `_ .. [9] `Bruzual (1983, ApJ, 273, 105) `_ .. [10] `Balogh et al. (1999, ApJ, 527, 54) `_