Output Data Products ==================== 3DCubeGen produces several types of output files depending on the command and spectrograph used. All output files are FITS format and are gzip-compressed by default. LVM Cubes --------- **Filename:** ``lvmCube-.fits.gz`` Generated by ``sincube`` and ``pipecube``. .. list-table:: :header-rows: 1 :widths: 10 20 70 * - HDU - Type - Content * - 0 - PrimaryHDU - Flux cube [n_wave, n_y, n_x]. Contains WCS header with RA/Dec (TAN projection) and wavelength (linear, Angstroms) axes. * - 1 - ImageHDU - Error cube [n_wave, n_y, n_x] (if ``errors: True``). Propagated errors from inverse-variance weighting. * - 2 - ImageHDU - Unity array (reserved) * - 3 - ImageHDU - Mask array (reserved) Key header keywords: - ``CRVAL1``, ``CRVAL2`` -- RA, Dec reference coordinates (deg) - ``CD1_1``, ``CD2_2`` -- pixel scale in RA, Dec (deg/pix) - ``CRVAL3``, ``CD3_3``, ``CRPIX3`` -- wavelength solution (Angstroms) - ``CTYPE3: WAVE`` -- air wavelength (linear) - ``IFUCON`` -- number of fibers used in reconstruction - ``BUNIT`` -- flux units (``10^-16 erg/s/cm^2`` when ``flu16: True``, otherwise ``erg/s/cm^2``) LVM Maps -------- **Filename:** ``lvmMap-_.fits.gz`` Generated by ``sinmap`` and ``pipemap``. .. list-table:: :header-rows: 1 :widths: 10 20 70 * - HDU - Type - Content * - 0 (FLUX) - PrimaryHDU - Flux map [n_y, n_x] in erg/s/cm\ :sup:`2`. Contains 2D WCS header with RA/Dec (TAN projection). * - 1 (MAG) - ImageHDU - Magnitude map [n_y, n_x] in AB mag/arcsec\ :sup:`2`. * - 2 - ImageHDU - Flux error map * - 3 - ImageHDU - Magnitude error map The ```` suffix corresponds to the photometric filter used: .. list-table:: :header-rows: 1 :widths: 15 85 * - Band - Description * - OII - [OII] 3728 A narrow-band * - OIII - [OIII] 5008 A narrow-band * - HI - H-alpha 6565 A narrow-band * - SII - [SII] 6733 A narrow-band * - g - SDSS g broad-band * - r - SDSS r broad-band * - i - SDSS i broad-band JPEG Composite Images --------------------- **Filename:** ``_.jpeg`` Generated by ``pipemap`` after all seven photometric bands are produced. These are three-color composite images constructed from the magnitude maps. Available composites: .. list-table:: :header-rows: 1 :widths: 15 30 55 * - Type - Channels (R, G, B) - Description * - OHS - [SII], H-alpha, [OIII] - Narrow-band emission line composite * - OOH - H-alpha, [OIII], [OII] - Narrow-band emission line composite * - gri - i, r, g - Broad-band continuum composite * - griOOH - Weighted blend - Combined broad-band + narrow-band with configurable weights LVM RSS (from cube) ------------------- **Filename:** ``lvmRSS-.fits.gz`` Generated by ``pipecube`` when ``cube2rss: True``, or manually via ``rssp_extract()`` after a ``sincube`` run (see :doc:`daptools`). Each non-zero spaxel in the input cube becomes one "fiber" row in the RSS. .. list-table:: :header-rows: 1 :widths: 8 18 16 58 * - HDU - EXTNAME - Status - Content * - 0 - ORIGINAL - Real - Primary header copied from the cube. ``POSCIRA``/``POSCIDE`` are set from the cube's ``CRVAL1``/``CRVAL2``. ``EXPOSURE`` is hardcoded to ``000000`` (not recoverable from the cube). * - 1 - FLUX - Real - Flux array [n_spaxels, n_wave] extracted spaxel-by-spaxel from cube HDU 0. Units match the cube (see `Flux Units`_ below). * - 2 - IVAR - Real\ [#err]_ - Inverse variance [n_spaxels, n_wave] computed as ``1 / error²`` from cube HDU 1. * - 3 - MASK - Placeholder - Zero array. No mask information is stored in the cube. * - 4 - WAVE - Real - Wavelength array [1, n_wave] in Angstroms, reconstructed from the cube header keywords ``CRVAL3``, ``CDELT3``/``CD3_3``, ``CRPIX3``. * - 5 - LSF - Placeholder - Ones array. The line spread function is not preserved in the cube. * - 6 - SKY_EAST - Placeholder - Ones array. Sky spectra are not stored in the cube. * - 7 - SKY_EAST_IVAR - Placeholder - Ones array. * - 8 - SKY_WEST - Placeholder - Ones array. * - 9 - SKY_WEST_IVAR - Placeholder - Ones array. * - 10 - SLITMAP - Real - Binary table. ``ra``/``dec`` are computed from the cube WCS. ``xpmm``/``ypmm`` store the pixel column/row in the cube for back-referencing. Bookkeeping columns (``targettype``, ``telescope``, ``ifulabel``, etc.) contain generic placeholder strings. .. [#err] Requires the cube to have been generated with ``errors: True``. If error propagation was disabled, HDU 1 of the cube is an array of ones and the IVAR extension will contain ones throughout. MEGARA Outputs -------------- **Cube:** ``megCube-.fits`` / ``megCube-_.fits.gz`` The MEGARA cube follows a similar structure to the LVM cube (flux in HDU 0, WCS header) but includes VPH grating information and spectrophotometric calibration metadata in the header. **Spectrum:** ``megSpec-_.fits.gz`` A 1D extracted spectrum generated by ``runfulldrp`` from the reconstructed cube. VirusP Outputs -------------- **Cube:** ``vpCube-.fits`` The VirusP cube follows the same structure as the LVM cube (flux in HDU 0 with 3D WCS, error in HDU 1 if enabled). The output is not gzip-compressed by default unless configured otherwise. Flux Units ---------- The flux unit convention depends on the ``flu16`` parameter: - ``flu16: True`` (default) -- flux values are in units of **10**\ :sup:`-16` **erg/s/cm**\ :sup:`2`\ **/A**. The header keyword ``BUNIT`` is set to ``10^-16 erg/s/cm^2``. - ``flu16: False`` -- flux values are in native units of **erg/s/cm**\ :sup:`2`\ **/A**. The 10\ :sup:`-16` scaling is applied by dividing the flux array by 10\ :sup:`-16`, so numerical values in the FITS file are larger and more convenient to work with.