DESI HETDEX Follow-up Value Added Catalog¶
Overview¶
This catalog contains HETDEX and DESI spectra of HETDEX Lyman Alpha Emitter candidates followed-up by DESI observations of two tiles. The file also contains the emission line fits from both sets of spectra. Details of the analysis can be found in Landriau et al. (2025, in preparation). The HETDEX data used in this file can be obtained from here.
Data Access¶
Data URL: https://data.desi.lbl.gov/public/dr1/vac/dr1/hetdex
NERSC access:
/global/cfs/cdirs/desi/public/dr1/vac/dr1/hetdex
Documentation¶
Files¶
DESI_HETDEX_SPEC_v1.6.fits: DESI spectra (from two tiles) of sources previously detected by HETDEXDESI_HETDEX_EXAMPLE.ipynb: Simple Jupyter notebook, showing how to plot the data in the fileDESI_HETDEX_EXAMPLE.html: HTML rendering of the Jupyter notebook.
Data Model¶
The data is organized in a binary table and 7 image headers.
The binary table (EXTNAME = INFO) has the following 34 columns:
| Name | Type | Units | Description |
|---|---|---|---|
| TARGETID | int64 | - | DESI targetid |
| TARGET_RA | float64 | deg | DESI target RA of fiber |
| TARGET_DEC | float64 | deg | DESI target DEC of fiber |
| TILEID | int64 | - | DESI tileid, either 80869 or 80870 |
| RA_HETDEX | float64 | deg | RA measured from HETDEX detection |
| DEC_HETDEX | float64 | deg | DEC measured from HETDEX detection |
| SEP | float64 | arcsec | Angular separation between target coordinates and those measured by HETDEX |
| DETECTID | int64 | - | HETDEX detection identifier number |
| VI_Z | float64 | - | Redshift determined from visual inspection of DESI spectra |
| VI_QUALITY | int64 | - | Determined from DESI spectra |
| SOURCE_TYPE | string | - | Determined from DESI spectra: LAE, OII, AGN, or other |
| DEX_FLAG | int64 | - | Certainty index of HETDEX detection |
| Z_BEST_0PT3 | float64 | - | z determined from HETDEX pipeline with threshold P(LAE)=0.3 |
| Z_BEST_0PT4 | float64 | - | z determined from HETDEX pipeline with threshold P(LAE)=0.4 |
| Z_BEST_0PT5 | float64 | - | z determined from HETDEX pipeline with threshold P(LAE)=0.5 (default pipeline setting) |
| AV | float64 | - | Dust extinction |
| GMAG | float64 | - | Pseudo g-magnitude measured from the HETDEX spectrum |
| SN_HETDEX | float64 | - | S/N of HETDEX source |
| WAVE_HETDEX | float64 | Angstrom | Wavelength of emission line determined from HETDEX fit |
| WAVE_ERR_HETDEX | float64 | Angstrom | Error on previous |
| FLUX_HETDEX | float64 | 10**-17 erg/(s cm2 Angstrom) | Emission line flux determined from HETDEX fit |
| FLUX_ERR_HETDEX | float64 | 10**-17 erg/(s cm2 Angstrom) | Error on previous |
| SIGMA_HETDEX | float64 | Angstrom | Line width (std dev of Gaussian) determined from HETDEX fit |
| SIGMA_ERR_HETDEX | float64 | Angstrom | Error on previous |
| CONT_HETDEX | float64 | 10**-17 erg/(s cm2 Angstrom) | Continuum level around the emission line determined from HETDEX fit |
| CONT_ERR_HETDEX | float64 | - | Error on previous |
| WAVE_DESI | float64 | Angstrom | Wavelength of emission line determined from DESI fit |
| WAVE_ERR_DESI | float64 | Angstrom | Error on previous |
| FLUX_DESI | float64 | 10**-17 erg/(s cm2 Angstrom) | Emission line flux determined from DESI fit |
| FLUX_ERR_DESI | float64 | - | Error on previous |
| SIGMA_DESI | float64 | Angstrom | Line width (std dev of Gaussian) determined from DESI fit |
| SIGMA_ERR_DESI | float64 | Angstrom | Error on previous |
| CONT_DESI | float64 | 10**-17 erg/(s cm2 Angstrom) | Continuum level around the emission line determined from HETDEX fit |
| CONT_ERR_DESI | float64 | 10**-17 erg/(s cm2 Angstrom) | Error on previous |
The seven image headers contain the spectra following:
| HDU Name | Units | Description |
|---|---|---|
| HETDEX_WAVE | Angstrom | HETDEX wavelength grid |
| HETDEX_SPEC | 10**-17 erg/(s cm2 Angstrom) | HETDEX spectra |
| HETDEX_SPEC_ERR | 10**-17 erg/(s cm2 Angstrom) | HETDEX spectrum errors |
| DESI_WAVE | Angstrom | DESI wavelength grid |
| DESI_WAVE_VACUUM | Angstrom | DESI (vacuum) wavelength grid |
| DESI_SPEC | 10**-17 erg/(s cm2 Angstrom) | DESI spectra |
| DESI_SPEC_ERR | 10**-17 erg/(s cm2 Angstrom) | DESI spectrum errors |
Contact¶
Contact Martin Landriau or Erin Mentuch Cooper for questions about this catalog.