.. _iron vac: Iron VAC (DR1) ============== .. contents:: Contents :depth: 3 Overview -------- This page describes the ``Iron`` value-added catalog, which will be publicly released as part of the `DESI Data Release 1 (DESI/DR1)`_ sometime in 2024 (exact date TBD). Please refer to the :ref:`acknowledgments` section for the conditions for using this VAC. .. note:: We only document the *latest* version of this VAC here; please see below for information regarding :ref:`previous versions`. Data Content & Access --------------------- Data from the ``Iron`` VAC can be accessed at any of the following links: ============================ ================================================================== Data url https://data.desi.lbl.gov/public/dr1/vac/dr1/fastspecfit/iron/v2.1 `NERSC`_ (for collaborators) ``/global/cfs/cdirs/desi/public/dr1/vac/dr1/fastspecfit/iron/v2.1`` ============================ ================================================================== For more information regarding the content and organization of the VAC, please click on the following links: * :ref:`Healpix Catalogs` * :ref:`Merged Catalogs` * :ref:`Sample Selection` * :ref:`Updated QSO Redshifts` Summary Statistics ------------------ The next two tables summarize the size and number of targets in each merged catalog. The first table gives the sample in each survey and program, while the second table combines all the individual programs into separate ``main``, ``sv``, and ``special`` catalogs. .. rst-class:: columns ================================= ========= ================= File Name File Size Number of Targets ================================= ========= ================= fastspec-iron-cmx-other.fits 11.2 MB 2,762 fastspec-iron-main-backup.fits 59.1 MB 15,163 fastspec-iron-main-bright.fits 24.6 GB 6,445,926 fastspec-iron-main-dark.fits 38.5 GB 10,075,557 fastspec-iron-special-backup.fits 2.31 MB 552 fastspec-iron-special-bright.fits 169 MB 43,261 fastspec-iron-special-dark.fits 58.3 MB 14,954 fastspec-iron-special-other.fits 166 MB 42,064 fastspec-iron-sv1-backup.fits 13.6 MB 3,331 fastspec-iron-sv1-bright.fits 506 MB 126,650 fastspec-iron-sv1-dark.fits 931 MB 233,201 fastspec-iron-sv1-other.fits 136 MB 34,112 fastspec-iron-sv2-backup.fits 593 KB 105 fastspec-iron-sv2-bright.fits 186 MB 46,486 fastspec-iron-sv2-dark.fits 211 MB 52,690 fastspec-iron-sv3-backup.fits 6.25 MB 1,524 fastspec-iron-sv3-bright.fits 1.04 GB 265,292 fastspec-iron-sv3-dark.fits 2.32 GB 592,190 fastspec-iron.fits 70.9 GB 17,995,820 ================================= ========= ================= The following table summarizes the number of QSO targets whose redshift has been updated using the procedure documented :ref:`here`. .. rst-class:: columns ================================= ================= =============================== Catalog Number of Objects Number with Corrected Redshifts ================================= ================= =============================== fastspec-iron-cmx-other.fits 2,762 34 fastspec-iron-main-backup.fits 15,163 0 fastspec-iron-main-bright.fits 6,445,926 348 fastspec-iron-main-dark.fits 10,075,557 59,907 fastspec-iron-special-backup.fits 552 0 fastspec-iron-special-bright.fits 43,261 2 fastspec-iron-special-dark.fits 14,954 137 fastspec-iron-special-other.fits 42,064 0 fastspec-iron-sv1-backup.fits 3,331 40 fastspec-iron-sv1-bright.fits 126,650 27 fastspec-iron-sv1-dark.fits 233,201 2,199 fastspec-iron-sv1-other.fits 34,112 67 fastspec-iron-sv2-backup.fits 105 0 fastspec-iron-sv2-bright.fits 46,486 1 fastspec-iron-sv2-dark.fits 52,690 485 fastspec-iron-sv3-backup.fits 1,524 0 fastspec-iron-sv3-bright.fits 265,292 28 fastspec-iron-sv3-dark.fits 592,190 1,668 fastspec-iron.fits 17,995,820 64,943 ================================= ================= =============================== Code & Template Versions ------------------------ The following tables document the code versions and environment variables used to produce this VAC. For details regarding the revision history of ``FastSpecFit``, please see the `change log`_. Note that the tagged dependencies can be retrieve from any FITS file with the following bit of code:: import fitsio from desiutil.depend import Dependencies codever = Dependencies(fitsio.read_header('/path/to/fastspecfit/file.fits, ext=0)) for codename, version in codever.items(): print(codename, version) .. rst-class:: columns ================ ========== Software Package Version(s) ================ ========== python 3.10.8 numpy 1.22.4 scipy 1.8.1 astropy 5.2.1 yaml 6.0 matplotlib 3.6.2 fitsio 1.1.8 desiutil 3.4.2 desispec 0.60.2 desitarget 2.7.0 desimodel 0.19.0 speclite 0.17 fastspecfit 2.5.0, 2.5.1 ================ ========== .. rst-class:: columns ==================== ===== Environment Variable Value ==================== ===== DESI_ROOT /dvs_ro/cfs/cdirs/desi DUST_DIR /dvs_ro/cfs/cdirs/cosmo/data/dust/v0_1 FPHOTO_DIR /dvs_ro/cfs/cdirs/desi/external/legacysurvey/dr9 FTEMPLATES_DIR /dvs_ro/cfs/cdirs/desi/science/gqp/templates/fastspecfit FTEMPLATES_FILE ftemplates-chabrier-1.3.0.fits (see `README.txt`_) FPHOTO_FILE /global/common/software/desi/perlmutter/desiconda/20230111-2.1.0/code/fastspecfit/2.5.1/lib/python3.10/site-packages/fastspecfit/data/legacysurvey-dr9.yaml EMLINES_FILE /global/common/software/desi/perlmutter/desiconda/20230111-2.1.0/code/fastspecfit/2.5.1/lib/python3.10/site-packages/fastspecfit/data/emlines.ecsv ==================== ===== .. _previous versions - iron: Notes & Known Issues -------------------- v2.1 (latest release) ~~~~~~~~~~~~~~~~~~~~~ * Release date: January 2024 * ``FastSpecFit`` version: ``2.5.0``, ``2.5.1`` * Templates: ``ftemplates-chabrier-1.3.0.fits`` (see `README.txt`_). * Notes: * Several updates to the spectrophotometric templates aimed at addressing the stellar mass bias identified in `issue/#159`_ (see `PR/#166`_): * Templates are now just solar metallicity (previously 0.1, 1, and 1.6 times solar). * Five age bins now (vs 8 previously). * Expanded velocity dispersion grid (new measurable maximum value is now 475 km/s). * Correction to how the light-weighted ages, dust attenuations, and SFRs were being computed. * When fitting the broad+narrow emission-line model, [OIII] 4959,5007 is now fitted separately and the narrow Balmer+helium+forbidden line-widths and velocity shifts are all tied together. * All known bugs fixed. * Known issues: * None at this time. v2.0 ~~~~ * Release date: August 2023 * ``FastSpecFit`` versions: ``2.4.1``, ``2.4.2`` * Templates: ``ftemplates-chabrier-1.1.0.fits`` (see `README.txt`_). * Notes: * Minor updates to spectrophotometric templates. * Just two rounds of emission-line fitting, not three (see `PR/#151`_). * Updated IGM attenuation coefficients (see `PR/#136`_). * Major algorithmic updates related to how emission-line amplitudes, fluxes, and inverse variances are computed, including a bug fix which the emission-line model spectra were not being convolved with the resolution matrix (see `PR/#137`_). * Known Issues: * **Warning**: Stellar masses are systematically higher (by 0.2-0.5 dex) compared to other methods, so they should be used with caution (see `issue/#159`_). Similarly, star-formation rates and other SPS model parameters have not been fully validated. * **Bug**: Fluxes (and EWs) of lines which lie in the camera-overlap region are overestimated by a factor of 2 due to a bug handling the different pixel scale (fixed in `PR/#157`_). v1.0 ~~~~ * Release date: February 2023 * ``FastSpecFit`` versions: ``2.1.0``, ``2.1.1`` * Templates: ``ftemplates-chabrier-1.0.0.fits`` (see `README.txt`_). * Known Issues: * **Bug**: [OII] 7320,7330 doublet amplitude ratio incorrectly inverted (fixed in `PR/#120`_). * **Bug**: Artificial redshift dependence in derived stellar masses due to age prior (fixed in `PR/#132`_). * **Bug**: Emission-line subtracted Dn(4000) values incorrectly computed (fixed in `PR/#135`_). .. _`DESI Data Release 1 (DESI/DR1)`: https://data.desi.lbl.gov/public/dr1 .. _`NERSC`: https://nersc.gov .. _`open a ticket`: https://github.com/desihub/fastspecfit/issues .. _`change log`: https://github.com/desihub/fastspecfit/blob/main/doc/changes.rst .. _`README.txt`: https://data.desi.lbl.gov/public/external/templates/fastspecfit/README.txt .. _`issue/#159`: https://github.com/desihub/fastspecfit/issues/159 .. _`PR/#120`: https://github.com/desihub/fastspecfit/pull/120 .. _`PR/#132`: https://github.com/desihub/fastspecfit/pull/132 .. _`PR/#135`: https://github.com/desihub/fastspecfit/pull/135 .. _`PR/#136`: https://github.com/desihub/fastspecfit/pull/136 .. _`PR/#137`: https://github.com/desihub/fastspecfit/pull/137 .. _`PR/#151`: https://github.com/desihub/fastspecfit/pull/151 .. _`PR/#157`: https://github.com/desihub/fastspecfit/pull/157 .. _`PR/#158`: https://github.com/desihub/fastspecfit/pull/158 .. _`PR/#166`: https://github.com/desihub/fastspecfit/pull/166