Loa fastspec VAC (DR2)

Warning

This VAC has not yet been publicly released. It is currently accessible only to DESI collaboration members via NERSC.

Overview

This page describes the Loa fastspec value-added catalog, which contains full spectrophotometric fitting results (continuum + emission lines) and will be publicly released as part of DESI Data Release 2 (DESI/DR2). For the companion photometry-only catalog, see the Loa fastphot 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 Loa fastspec VAC can be accessed at any of the following links:

Data url

https://data.desi.lbl.gov/desi/vac/dr2/fastspecfit/loa/v1.0

NERSC (for collaborators)

/global/cfs/cdirs/desi/vac/dr2/fastspecfit/loa/v1.0

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

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

fastspec-loa-cmx-other.fits

12 MB

2,765

File Name

File Size

Number of Targets

fastspec-loa-sv1-backup.fits

5.11 MB

1,145

fastspec-loa-sv1-bright.fits

542 MB

126,658

fastspec-loa-sv1-dark.fits

1.01e+03 MB

235,821

fastspec-loa-sv1-other.fits

145 MB

34,004

Total (sv1)

1.66 GB

397,628

File Name

File Size

Number of Targets

fastspec-loa-sv2-backup.fits

652 KB

107

fastspec-loa-sv2-bright.fits

199 MB

46,491

fastspec-loa-sv2-dark.fits

225 MB

52,693

Total (sv2)

425 MB

99,291

File Name

File Size

Number of Targets

fastspec-loa-sv3-backup.fits

6.91 MB

1,573

fastspec-loa-sv3-bright.fits

1.11 GB

265,307

fastspec-loa-sv3-dark.fits

2.48 GB

592,128

Total (sv3)

3.6 GB

859,008

File Name

File Size

Number of Targets

fastspec-loa-special-backup.fits

2.32 MB

512

fastspec-loa-special-bright.fits

450 MB

105,172

fastspec-loa-special-dark.fits

1.15 GB

261,706

Total (special)

1.6 GB

367,390

File Name

File Size

Number of Targets

fastspec-loa-main-backup.fits

252 MB

60,372

fastspec-loa-main-bright-nside1-hp00.fits

1.33 GB

325,494

fastspec-loa-main-bright-nside1-hp01.fits

11 GB

2,693,426

fastspec-loa-main-bright-nside1-hp02.fits

12.9 GB

3,141,532

fastspec-loa-main-bright-nside1-hp03.fits

2.63 GB

641,198

fastspec-loa-main-bright-nside1-hp04.fits

9.36 GB

2,285,745

fastspec-loa-main-bright-nside1-hp05.fits

1.67 GB

408,754

fastspec-loa-main-bright-nside1-hp06.fits

9.67 GB

2,359,953

fastspec-loa-main-bright-nside1-hp07.fits

3.07 GB

749,725

fastspec-loa-main-bright-nside1-hp08.fits

1.26 GB

307,648

fastspec-loa-main-bright-nside1-hp09.fits

292 MB

69,672

fastspec-loa-main-bright-nside1-hp10.fits

254 MB

60,466

fastspec-loa-main-bright-nside1-hp11.fits

595 MB

141,886

fastspec-loa-main-dark-nside1-hp00.fits

3.47 GB

846,678

fastspec-loa-main-dark-nside1-hp01.fits

16.1 GB

3,937,260

fastspec-loa-main-dark-nside1-hp02.fits

15.3 GB

3,730,928

fastspec-loa-main-dark-nside1-hp03.fits

2.37 GB

578,709

fastspec-loa-main-dark-nside1-hp04.fits

21 GB

5,112,856

fastspec-loa-main-dark-nside1-hp05.fits

3.54 GB

864,168

fastspec-loa-main-dark-nside1-hp06.fits

22.2 GB

5,426,022

fastspec-loa-main-dark-nside1-hp07.fits

6.62 GB

1,616,210

fastspec-loa-main-dark-nside1-hp08.fits

3.18 GB

775,136

fastspec-loa-main-dark-nside1-hp09.fits

657 MB

156,454

fastspec-loa-main-dark-nside1-hp10.fits

588 MB

140,162

fastspec-loa-main-dark-nside1-hp11.fits

372 MB

88,647

Total (main)

150 GB

36,519,101

The following tables summarize the number of QSO targets whose redshift has been updated using the procedure documented here.

Catalog

Number of Objects

Number with Corrected Redshifts

fastspec-loa-cmx-other.fits

2,765

35

Catalog

Number of Objects

Number with Corrected Redshifts

fastspec-loa-sv1-backup.fits

1,145

17

fastspec-loa-sv1-bright.fits

126,658

34

fastspec-loa-sv1-dark.fits

235,821

2,958

fastspec-loa-sv1-other.fits

34,004

71

Total (sv1)

397,628

3,080

Catalog

Number of Objects

Number with Corrected Redshifts

fastspec-loa-sv2-backup.fits

107

0

fastspec-loa-sv2-bright.fits

46,491

2

fastspec-loa-sv2-dark.fits

52,693

674

Total (sv2)

99,291

676

Catalog

Number of Objects

Number with Corrected Redshifts

fastspec-loa-sv3-backup.fits

1,573

0

fastspec-loa-sv3-bright.fits

265,307

42

fastspec-loa-sv3-dark.fits

592,128

2,465

Total (sv3)

859,008

2,507

Catalog

Number of Objects

Number with Corrected Redshifts

fastspec-loa-special-backup.fits

512

0

fastspec-loa-special-bright.fits

105,172

1

fastspec-loa-special-dark.fits

261,706

242

Total (special)

367,390

243

Catalog

Number of Objects

Number with Corrected Redshifts

fastspec-loa-main-backup.fits

60,372

0

fastspec-loa-main-bright-nside1-hp00.fits

325,494

27

fastspec-loa-main-bright-nside1-hp01.fits

2,693,426

260

fastspec-loa-main-bright-nside1-hp02.fits

3,141,532

270

fastspec-loa-main-bright-nside1-hp03.fits

641,198

60

fastspec-loa-main-bright-nside1-hp04.fits

2,285,745

206

fastspec-loa-main-bright-nside1-hp05.fits

408,754

35

fastspec-loa-main-bright-nside1-hp06.fits

2,359,953

220

fastspec-loa-main-bright-nside1-hp07.fits

749,725

54

fastspec-loa-main-bright-nside1-hp08.fits

307,648

25

fastspec-loa-main-bright-nside1-hp09.fits

69,672

3

fastspec-loa-main-bright-nside1-hp10.fits

60,466

5

fastspec-loa-main-bright-nside1-hp11.fits

141,886

11

fastspec-loa-main-dark-nside1-hp00.fits

846,678

6,781

fastspec-loa-main-dark-nside1-hp01.fits

3,937,260

30,565

fastspec-loa-main-dark-nside1-hp02.fits

3,730,928

27,213

fastspec-loa-main-dark-nside1-hp03.fits

578,709

6,712

fastspec-loa-main-dark-nside1-hp04.fits

5,112,856

34,425

fastspec-loa-main-dark-nside1-hp05.fits

864,168

5,805

fastspec-loa-main-dark-nside1-hp06.fits

5,426,022

30,824

fastspec-loa-main-dark-nside1-hp07.fits

1,616,210

10,651

fastspec-loa-main-dark-nside1-hp08.fits

775,136

5,529

fastspec-loa-main-dark-nside1-hp09.fits

156,454

932

fastspec-loa-main-dark-nside1-hp10.fits

140,162

924

fastspec-loa-main-dark-nside1-hp11.fits

88,647

1,027

Total (main)

36,519,101

162,564

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

desiutil

3.4.3

desispec

0.68.1

desitarget

2.8.0

speclite

0.20

fastspecfit

3.1.4

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: 2027 (Exact date TBD)

  • FastSpecFit version: 3.1.4

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

  • Notes:

    • Initial release of the Loa fastspec VAC.

  • Known issues:

    • Bug: Significant errors in flux and equivalent-width inverse-variance estimates (fixed in 3.1.5; see PR/#213).

    • Bug: Poor line fits for a small fraction of strong emission lines due to a clipping error in the ivar2var function (fixed in 3.2.0; see PR/#228).