Iron fastphot VAC (DR1)

Overview

This page describes the Iron fastphot value-added catalog, which contains photometry-only continuum fitting results and was publicly released as part of DESI Data Release 1 (DESI/DR1). For the companion full spectrophotometric catalog, see the Iron fastspec VAC.

Please refer to the 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 previous versions.

Data Content & Access

Data from the Iron fastphot VAC can be accessed at any of the following links:

Data url

https://data.desi.lbl.gov/desi/vac/dr1/fastphot/iron/v1.0

NERSC (for collaborators)

/global/cfs/cdirs/desi/vac/dr1/fastphot/iron/v1.0

For more information regarding the content and organization of the VAC, please click on the following links:

Updated QSO Redshifts

The QSO redshift corrections applied to this VAC are identical to those used in the Iron fastspec VAC; refer to that page for the algorithm description and per-catalog correction counts.

Summary Statistics

The following tables summarize the size and number of targets in each merged catalog, organized by survey and program.

File Name

File Size

Number of Targets

fastphot-iron-cmx-other.fits

2.34 MB

2,762

File Name

File Size

Number of Targets

fastphot-iron-sv1-backup.fits

2.95 MB

3,331

fastphot-iron-sv1-bright.fits

106 MB

126,650

fastphot-iron-sv1-dark.fits

196 MB

233,202

fastphot-iron-sv1-other.fits

28.6 MB

34,112

Total (sv1)

334 MB

397,295

File Name

File Size

Number of Targets

fastphot-iron-sv2-backup.fits

132 KB

105

fastphot-iron-sv2-bright.fits

39.3 MB

46,486

fastphot-iron-sv2-dark.fits

44.4 MB

52,690

Total (sv2)

83.8 MB

99,281

File Name

File Size

Number of Targets

fastphot-iron-sv3-backup.fits

1.33 MB

1,524

fastphot-iron-sv3-bright.fits

229 MB

265,293

fastphot-iron-sv3-dark.fits

511 MB

592,191

Total (sv3)

741 MB

859,008

File Name

File Size

Number of Targets

fastphot-iron-special-backup.fits

458 KB

552

fastphot-iron-special-bright.fits

32.1 MB

43,261

fastphot-iron-special-dark.fits

11.1 MB

14,954

fastphot-iron-special-other.fits

32.9 MB

42,064

Total (special)

76.5 MB

100,831

File Name

File Size

Number of Targets

fastphot-iron-main-backup.fits

11.2 MB

15,163

fastphot-iron-main-bright-nside1-hp00.fits

76.8 MB

101,838

fastphot-iron-main-bright-nside1-hp01.fits

766 MB

1,017,041

fastphot-iron-main-bright-nside1-hp02.fits

1.02e+03 MB

1,358,627

fastphot-iron-main-bright-nside1-hp03.fits

304 MB

403,581

fastphot-iron-main-bright-nside1-hp04.fits

740 MB

981,600

fastphot-iron-main-bright-nside1-hp05.fits

227 MB

301,057

fastphot-iron-main-bright-nside1-hp06.fits

1.02e+03 MB

1,347,464

fastphot-iron-main-bright-nside1-hp07.fits

508 MB

673,711

fastphot-iron-main-bright-nside1-hp08.fits

61.6 MB

81,734

fastphot-iron-main-bright-nside1-hp09.fits

50.4 MB

66,856

fastphot-iron-main-bright-nside1-hp10.fits

34.4 MB

45,570

fastphot-iron-main-bright-nside1-hp11.fits

50.4 MB

66,848

fastphot-iron-main-dark-nside1-hp00.fits

269 MB

352,447

fastphot-iron-main-dark-nside1-hp01.fits

853 MB

1,118,746

fastphot-iron-main-dark-nside1-hp02.fits

1.26 GB

1,699,122

fastphot-iron-main-dark-nside1-hp03.fits

164 MB

214,658

fastphot-iron-main-dark-nside1-hp04.fits

1.29 GB

1,739,317

fastphot-iron-main-dark-nside1-hp05.fits

441 MB

579,026

fastphot-iron-main-dark-nside1-hp06.fits

2.12 GB

2,851,879

fastphot-iron-main-dark-nside1-hp07.fits

787 MB

1,032,151

fastphot-iron-main-dark-nside1-hp08.fits

165 MB

216,757

fastphot-iron-main-dark-nside1-hp09.fits

119 MB

156,454

fastphot-iron-main-dark-nside1-hp10.fits

56.8 MB

74,463

fastphot-iron-main-dark-nside1-hp11.fits

31 MB

40,609

Total (main)

12.3 GB

16,536,719

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.

Software Package

Version(s)

python

3.10.14

numpy

1.22.4

scipy

1.8.1

astropy

6.0.1

yaml

6.0.1

matplotlib

3.8.4

fitsio

1.2.1

mpi4py

3.1.6

healpy

1.16.6

desiutil

3.4.3

desispec

0.68.1

desitarget

2.8.0

speclite

0.20

fastspecfit

3.2.0

Environment Variable

Value

DESI_ROOT

/global/cfs/cdirs/desi

DUST_DIR

/dvs_ro/cfs/cdirs/desi/external/dust/v0_1

FPHOTO_DIR

/dvs_ro/cfs/cdirs/desi/external/legacysurvey/dr9

FTEMPLATES_DIR

/dvs_ro/cfs/cdirs/desi/public/external/templates/fastspecfit

FTEMPLATES_FILE

ftemplates-chabrier-2.0.0.fits (see README.txt)

Notes & Known Issues

v1.0 (latest release)

  • Release date: June 2026

  • FastSpecFit version: 3.2.0

  • Templates: ftemplates-chabrier-2.0.0.fits (see README.txt).

  • Notes:

    • Initial public release of the Iron fastphot VAC.

  • Known issues:

    • None at this time.