What’s New in the DAP

MPL-9 (2.4.1)

High-level changes

  • Extensions SPX_ELLCOO and BIN_LWELLCOO have a new channel. The 4 channels are now radius in arcsec, radius in \(R_{\rm eff}\), radius in \(h^{-1}{\rm kpc}\), and azimuth; the third channel is the new one. So the channels are:

    C1      = 'Elliptical radius'  / Data in channel 1
    U1      = 'arcsec  '           / Units of data in channel 1
    C2      = 'R/Re    '           / Data in channel 2
    U2      = '' / Units of data in channel 2
    C3      = 'R h/kpc '           / Data in channel 3
    U3      = 'kpc/h   '           / Units of data in channel 3
    C4      = 'Elliptical azimuth' / Data in channel 4
    U4      = 'degrees '           / Units of data in channel 4
  • The following extensions were added to the MAPS files:

    • EMLINE_SEW_CNT: Continuum used for summed-flux equivalent-width measurement
    • EMLINE_GEW_CNT: Continuum used for Gaussian-fit equivalent-width measurement
    • SPECINDEX_BCEN: Flux-weighted center of the blue sideband in the spectral-index measurement
    • SPECINDEX_BCNT: Continuum level in the blue sideband used in the spectral-index measurement
    • SPECINDEX_RCEN: Flux-weighted center of the red sideband in the spectral-index measurement
    • SPECINDEX_RCNT: Continuum level in the red sideband used in the spectral-index measurement
    • SPECINDEX_MODEL: Index measurement made using the best-fitting stellar continuum model.
  • All emission-line extensions now contain 35 lines, and channel ordering of the line list has changed compared to MPL-8. Current ordering is:

    C01     = 'OII-3727'           / Data in channel 1
    C02     = 'OII-3729'           / Data in channel 2
    C03     = 'H12-3751'           / Data in channel 3
    C04     = 'H11-3771'           / Data in channel 4
    C05     = 'Hthe-3798'          / Data in channel 5
    C06     = 'Heta-3836'          / Data in channel 6
    C07     = 'NeIII-3869'         / Data in channel 7
    C08     = 'HeI-3889'           / Data in channel 8
    C09     = 'Hzet-3890'          / Data in channel 9
    C10     = 'NeIII-3968'         / Data in channel 10
    C11     = 'Heps-3971'          / Data in channel 11
    C12     = 'Hdel-4102'          / Data in channel 12
    C13     = 'Hgam-4341'          / Data in channel 13
    C14     = 'HeII-4687'          / Data in channel 14
    C15     = 'Hb-4862 '           / Data in channel 15
    C16     = 'OIII-4960'          / Data in channel 16
    C17     = 'OIII-5008'          / Data in channel 17
    C18     = 'NI-5199 '           / Data in channel 18
    C19     = 'NI-5201 '           / Data in channel 19
    C20     = 'HeI-5877'           / Data in channel 20
    C21     = 'OI-6302 '           / Data in channel 21
    C22     = 'OI-6365 '           / Data in channel 22
    C23     = 'NII-6549'           / Data in channel 23
    C24     = 'Ha-6564 '           / Data in channel 24
    C25     = 'NII-6585'           / Data in channel 25
    C26     = 'SII-6718'           / Data in channel 26
    C27     = 'SII-6732'           / Data in channel 27
    C28     = 'HeI-7067'           / Data in channel 28
    C29     = 'ArIII-7137'         / Data in channel 29
    C30     = 'ArIII-7753'         / Data in channel 30
    C31     = 'Peta-9017'          / Data in channel 31
    C32     = 'SIII-9071'          / Data in channel 32
    C33     = 'Pzet-9231'          / Data in channel 33
    C34     = 'SIII-9533'          / Data in channel 34
    C35     = 'Peps-9548'          / Data in channel 35
  • Fixed flux ratios of doublets were improved using the following calculation: \(\lambda_2/\lambda_1\ \cdot\ (M1_1+E2_1)/(M1_2+E2_2)\), where \(M1\) and \(E2\) are the magnetic dipole and electric quadrapole Einstein \(A\) coefficients and \(\lambda\) is the line wavelength. The Einstein \(A\) coefficients are all taken from NIST. In all but the [O II] 7320,7330 complex (not included in MPL-9 fit), the magnetic dipole term dominates such that the electric quadrapole terms are effectively irrelevant. The fixed flux ratios are:

    • NeIII-3968/NeIII-3968 = 0.3
    • OIII-4960/OIII-5008 = 0.35
    • OI-6365/OI-6302 = 0.32
    • NII-6549/NII-6585 = 0.34
    • SIII-9071/SIII-9533 = 0.41
  • Lines with tied velocity dispersions (some because their fluxes are also tied) are:

    • OII-3727 + OII-3729
    • HeI-3889 + Hzet-3890
    • NeIII-3968 + NeIII-3968
    • OIII-4960 + OIII-5008
    • NI-5199 + NI-5201
    • OI-6302 + OI-6365
    • NII-6549 + NII-6585
    • SIII-9071 + SIII-9533

User-level changes/bug fixes

  • Allow emission-line moment, modeling, and spectral-index keys to be None, meaning that the DAP only fits the stellar kinematics but still produces the MAPS and LOGCUBE files.
  • Added beta version of hierarchically clustered MaStar templates
  • Added a script that computes the weights used during the ppxffit_qa plot construction.

Minor changes/bug fixes

  • Hotfix to accommodate change in padding computation in ppxf>=6.7.15
  • Fixed units bug in mangadap.proc.util.flux_to_fnu().
  • Fixed bug in templates when using iteration_mode = 'global_template'
  • Change from time.clock() to time.perf_counter()
  • Bug fix in record array dimensionality when writing to binary table
  • Minor plotting changes for Overview paper plots
  • Fixed masking of emission-line chi-square measurements
  • Remove MASKNAME header keyword inherited from DRP files

MPL-8 (2.3.0)

High-level changes

  • Change to DAPTYPE construction. DAPTYPE is now binning - stellar templates - emission-line templates. This was done because in future releases we plan to switch the templates used for the stellar kinematics (likely to remain MILESHC) to a different template set for the emission-line modeling with a longer spectral range to fit the full MaNGA spectral range.
  • Three additional emission-lines are fit: He I at 3889 angstroms, and the [N I] doublet at 5200 angstroms. The He I line has its dispersion tied to H:math:zeta at 3890, and the dispersions of the [N I] doublet are tied.
  • The MAPS file extensions were modified:
    • STELLAR_SIGMACORR now has two channels. The first provides the correction constructed using the same methodology as in MPL-7/DR15; the second provides a correction that we are currently testing for robustness as a replacement correction.
    • The data in the STELLAR_CONT_FRESID and STELLAR_CONT_RCHI2 extensions has been consolidated into a new single extension, STELLAR_FOM (FOM=figure-of-merit). Channel 3 of STELLAR_FOM is the same as STELLAR_CONT_RCHI2, and channels 4 and 5 are the same as the two channels in STELLAR_CONT_FRESID. See the data model for the full description of the additional channels in this extension.
    • 4 additional channels are provided related to the emission lines:
      • EMLINE_GA: The amplitude of the fitted Gaussians
      • EMLINE_GANR: The amplitude over noise of the fitted Gaussians
      • EMLINE_FOM: Full-spectrum figures-of-merit for the emission-line module; this now has exactly the same format as the STELLAR_FOM extension
      • EMLINE_LFOM: The reduced chi-square in 15 pixel windows around each fitted emission line.
  • To make the files easier to use, the LOGCUBE extensions were modified:
    • The EMLINE_BASE and EMLINE_MASK extensions have been removed.
    • The following extensions have been added:
      • MODEL_MASK is the mask to use with the MODEL extension (the result of the emission-line+continuum fit)
      • STELLAR is best-fitting stellar continuum from the stellar continuum fit
      • STELLAR_MASK is the mask for the stellar-continuum fit.
  • Numerous QA plots have been added; see the data model description.

Under-the-hood algorithmic changes

  • Allow the emission-line fitter to use the bin ID numbers directly instead of matching the spaxels to bins by coordinate proximity
  • Construction of the parameter tying object in the emission-line fitter is now done just before each spectrum is fit by ppxf (not globally in Sasuke) to better handle when components are omitted.
  • When deconstructing bins into spaxels for the emission-line modeling (hybrid binning scheme), the second fit iteration only fits spaxels that are components of binned spectra and does not refit spectra that constitute an entire bin themselves. I.e. this removes some largely redundant fitting.
  • mangadap.proc.ppxffit.PPXFFit and mangadap.proc.sasuke.Sasuke include calculations of the chi-square growth; and changed the names of the growth columns in the reference files.
  • Changed definitions of \(A\) to be the model amplitude; \(A/N\) is the model amplitude divided by the median noise in the two sidebands defined for the emission-line EW calculation.
  • Major changes to survey-level execution of the DAP, including that the input data is now pulled from the DRPall file instead of the plateTargets files.
  • Ignore minimum \(S/N\) limitation in emission-line moments and spectral indices for hybrid scheme as a stop-gap to minimize differences in moments, models, and indices BINID.

User-level changes/bug fixes

  • Fixed an error in setting up the tying structure passed to pPXF that led to the [O II] dispersion maps being fully masked.
  • Fixed an error in the propagation of the error in the passband integral calculation, which affects the non-parameteric emission-line measurement errors (summed data) and the spectral index errors. The calculation is now formally correct, but these propagated errors are still underestimated with respect to more robust calculations via an MC.
  • Fixed a bug that omitted the FORESTAR flag from getting propagated in the hybrid binning case.
  • Fixed \(\chi^2\) calculations reported in MAPS files (does not affect chi-square used during fit optimization) for both the stellar-continuum fit and the emission-line modeling.
  • Velocity-dispersion corrections are now applied to the spectral indices summary data provided in the DAPall file.
  • Fixed minor issue in propagating masks from the reference files to the maps files; primarily an issue for the hybrid binning scheme.

Minor changes/bug fixes

  • Fixed the bug that led to the error in the sigma corrections for MPL-7, what were replaced before distributing these data via DR15.
  • Fixed bug that was causing multiple instances of “Warning: converting a masked element to nan” during the emission-line moment measurements.
  • Significant changes to the pixel resampling code, but has a minor effect on the results.