AGN Host Galaxies Physical Properties VAC¶
Overview¶
This value-added catalog contains physical properties of DESI EDR galaxies derived through spectral energy distribution (SED) fitting with the Code Investigating GALaxy Emission (CIGALE v.22.1; Boquien et al. 2019) accounting for Active Galactic Nuclei (AGN) contribution. CIGALE is based on the principles of the energy balance between dust-absorbed stellar emission in the ultraviolet and optical bands and its re-emission in the infrared (IR). It is widely used to estimate the physical properties of galaxies and AGN in large galaxy surveys (e.g. Ciesla et al. 2015; Malek et al. 2018; Salim et al. 2018; Mountrichas et al. 2021; Yang et al. 2020, 2022). A more detailed description of the catalog can be found in Siudek et al. (in preparation).
To generate the grid of models we use a delayed star formation history (SFH) model with an optional exponential burst and Bruzal & Charlot 2003 single stellar population models assuming Chabrier 2003 initial mass function and solar metallicity. We also include the standard nebular emission model from Inoue et al. 2011 and model dust attenuation using the Calzetti et al. 2000 attenuation curve. The reprocessed dust emission is modeled by adopting the dust emission models of Dale et al. 2014. The AGN emission is modeled using the models from Fritz et al. 2006. CIGALE simultaneously fits the AGN and galaxy component using all the available photometry (g, r, z, W1, W2, W3, and W4) and returns estimates of the main galaxy properties such as stellar mass, star formation rate, and the relative contribution of the dusty torus of the AGN to the total IR luminosity - the AGN fraction using a Bayesian-like analysis. We note that incorporating AGN models does not exclude a scenario where the galaxy does not host an AGN (or its emission is negligible). In such cases, the AGN fraction is close to 0 (AGNfrac < 0.1). The reduced chi2 expresses the quality of the fit, and the estimates and errors of physical properties are the likelihood-weighted means and standard deviations of the probability distribution function, respectively (Boquien et al. 2019). The cosmology assumed is WMAP7.
The catalog accounts for ~1.3 of million EDR galaxies independently of the main target type. This catalog aims to have a uniform catalog across the main targets (BGS, LRG, ELG, and QSO) accounting for a possible AGN contribution. The selection of the samples (credit to Ragadeepika Pucha) is as follows:
- Started with zall-pix-fuji.fits catalog (2,847,435 rows)
- Applied the following cuts:
- COADD_FIBERSTATUS = 0
- ZWARN = 0 | ZWARN = 4
- ZCAT_PRIMARY = True
- SPECTYPE = GALAXY|QSO
- Total 1,352,842 unique objects
- Joined with John Moustakas’s LS Tractor Photometry VAC and removed any duplicates.
- Select only candidates with LS DR9 photometry (RELEASE > 9000) (1,292,030 sources)
- Join the fastspec catalog (1,286,124 sources)
Data Access¶
Data URL: https://data.desi.lbl.gov/public/edr/vac/edr/cigale/
NERSC access for DESI collaborators:
/global/cfs/cdirs/desi/public/edr/vac/edr/cigale/
Documentation¶
Files¶
FujiPhysProp_v1.4.fits: physical properties of DESI EDR galaxies.FujiPhysProp_AfterBurner_v1.4.fits: supplementary table with physical properties for 8422 sources obtained based on the redshift from the afterburners.
Example Usage¶
An accompanying jupyter notebook documents the example of using the catalog.
The easiest way to open and inspect the catalog is with Table, you can also convert it to pandas:
from astropy.table import Table
import pandas as pd
catalog = Table.read('FujiPhysProp_v1.4.fits', format='fits')
catalog_df = catalog.to_pandas()
Data Model¶
| NAME | FORMAT | UNITS | DESCRIPTION |
|---|---|---|---|
| TARGETID | int64 | - | Unique DESI Target ID |
| SURVEY | bytes7 | - | Survey name |
| PROGRAM | bytes7 | - | Program name |
| HEALPIX | int32 | - | Healpix number |
| SPECTYPE | bytes7 | - | Redrock spectral classification |
| RA | float64 | deg | Right ascension from target catalog |
| DEC | float64 | deg | Declination from target catalog |
| RELEASE | int16 | - | Legacy Surveys (LS) Release |
| Z | float64 | - | Redshift |
| CHI2 | float64 | - | reduced chi2 defining the quality of the fit |
| LOGM | float64 | log(solMass) | logarithm of the stellar mass |
| LOGM_ERR | float64 | log(solMass) | error on logarithm of the stellar mass |
| LOGSFR | float64 | log(solMass/yr) | logarithm of the star formation rate averaged over 10Myr |
| LOGSFR_ERR | float64 | log(solMass/yr) | error on logarithm of star formation rate averaged over 10Myr |
| AGNLUM | float64 | W | total luminosity of the AGN in W |
| AGNFRAC | float64 | - | fraction of the total IR emission coming from the AGN, where 0 means no AGN contribution and 1 means 100% AGN contribution |
| AGNPSY | float64 | deg | viewing angle, with ~30deg and ~70deg, for type 1 and type 2 AGN, respectively |
| LNU_(U/G/R/I/Z) | float64 | W/Hz | rest-frame luminosity in a given band, the rest-frame magnitudes can be derived using eq. -2.5*log10(Lnu)+34.1 |
| NUVR,RK,UV,VJ,GR | float64 | AB mag | rest-frame colors in given bands |
| LNU_(U/G/R/I/Z)_ERR | float64 | W/Hz | error of the rest-frame luminosity in a given band |
| (NUVR, RK, UV, VJ, GR)_ERR | float64 | AB mag | error of the rest-framed colors in given bands |
| AGE | float64 | Myr | age of the main stellar population |
| AGE_ERR | float64 | Myr | error of the age of the main stellar population |
| AGEM | float64 | Myr | mass-weighted age of the main stellar population |
| AGEM_ERR | float64 | Myr | error of the mass-weighted age of the main stellar population |
| TAU | float64 | Myr | e-folding time of the main stellar population |
| TAU_ERR | float64 | Myr | error of the e-folding time of the main stellar population |
| FRACYSSP | float64 | Myr | mass fraction of young stellar population |
| FRACYSSP_ERR | float64 | Myr | error of the mass fraction of young stellar population |
| FLAG_MASSPDF | float64 | - | Flag expressed by Mbest/Mbayes to reject stellar mass estimates with broad PDF and/or complex likelihood distribution, e.g. to clean the sample the recommended flag is 1/5 ≲ Mbest/Mbayes ≲ 5 |
| FLAG_SFRPDF | float64 | - | Flag expressed by SFRbest/SFRbayes to reject SFR estimates with broad PDF and/or complex likelihood distribution, e.g. to clean the sample the recommended flag is 1/5 ≲ SFRbest/SFRbayes ≲ 5 |
| FLAGOPTICAL | int64 | - | Flag to preselect sources observed with high signal-to-noise: S/N ≥ 10 in optical bands(g, r, z). FLAGOPTICAL = 3(2/1/0) source is observed in 3(2/1/0) band(s) with S/N ≥ 10 |
| FLAGINFRARED | int64 | - | Flag to preselect sources observed with high signal-to-noise: S/N ≥ 3 in WISE bands(W1, W2, W3, W4). FLAGINFRARED = 4(3/2/1/0) source is observed in 4(3/2/1/0) band(s) with S/N ≥ 3 |
| FLUX_(G/R/Z/W1-4) | float32 | nanomaggy | Flux in a given band; For the reddening corrected flux use the eq. DERED_FLUX = FLUX_BAND/MW_TRANSMISSION_BAND; for magnitude follow eq. MAG_BAND = -2.5*log10(DERED_FLUX) + 22.5 |
| FLUX_IVAR_(G/R/Z/W1-4) | float32 | nanomaggy^-2 | Inverse variance of the flux in a given band |
| MW_TRANSMISSION_(G/R/Z/W1-4) | float32 | - | Milky Way foreground dust transmission factor [0-1] in a given band. |
| SNR_(G/R/Z/W1-4) | float32 | - | signal-to-noise in a given band calculated as FLUX*sqrt(FLUX_IVAR) |
Contact¶
Contact Malgorzata Siudek with any questions.
Change Log¶
v1.0¶
The initial catalog
v1.1¶
- adding additional columns:
| NAME | FORMAT | UNITS | DESCRIPTION |
|---|---|---|---|
| RA | float64 | deg | Right ascension from target catalog |
| DEC | float64 | deg | Declination from target catalog |
| RELEASE | int16 | - | Legacy Surveys (LS) Release |
| FLAG_MASSPDF | float64 | - | Flag expressed by Mbest/Mbayes to reject stellar mass estimates with broad PDF and/or complex likelihood distribution, e.g. to clean the sample the recommended flag is 1/5 ≲ Mbest/Mbayes ≲ 5 |
| FLAG_SFRPDF | float64 | - | Flag expressed by SFRbest/SFRbayes to reject SFR estimates with broad PDF and/or complex likelihood distribution, e.g. to clean the sample the recommended flag is 1/5 ≲ SFRbest/SFRbayes ≲ 5 |
| FLAGOPTICAL | int64 | - | Flag to preselect sources observed with high signal-to-noise: S/N ≥ 10 in optical bands(g, r, z). FLAGOPTICAL = 3(2/1/0) source is observed in 3(2/1/0) band(s) with S/N ≥ 10 |
| FLAGINFRARED | int64 | - | Flag to preselect sources observed with high signal-to-noise: S/N ≥ 3 in WISE bands(W1, W2, W3, W4). FLAGINFRARED = 4(3/2/1/0) source is observed in 4(3/2/1/0) band(s) with S/N ≥ 3 |
| FLUX_(G/R/Z/W1-4) | float32 | nanomaggy | Flux in a given band; For the reddening corrected flux use the eq. DERED_FLUX = FLUX_BAND/MW_TRANSMISSION_BAND; for magnitude follow eq. MAG_BAND = -2.5*log10(DERED_FLUX) + 22.5 |
| FLUX_IVAR_(G/R/Z/W1-4) | float32 | nanomaggy^-2 | Inverse variance of the flux in a given band |
| MW_TRANSMISSION_(G/R/Z/W1-4) | float32 | - | Milky Way foreground dust transmission factor [0-1] in a given band. |
| SNR_(G/R/Z/W1-4) | float32 | - | signal-to-noise in a given band calculated as FLUX*sqrt(FLUX_IVAR) |
- changing the name of columns: redshift to Z
- fixing the columns types and adding units
v1.2¶
- updating the columns FLAG_MASSPDF and FLAG_SFRPDF
v1.3¶
- adding 51,126 that were missing due to the release empty column. For 1405 of them the proper model was not found and the physical values are fixed to = -99
- adding supplementary table (
FujiPhysProp_AfterBurnerv1.3) with physical properties for 8422 sources obtained based on the redshift from the afterburners.
v1.4¶
-
adding new columns:
NAME FORMAT UNITS DESCRIPTION AGE float64 Myr age of the main stellar population AGE_ERR float64 Myr error of the age of the main stellar population AGEM float64 Myr mass-weighted age of the main stellar population AGEM_ERR float64 Myr error of the mass-weighted age of the main stellar population TAU float64 Myr e-folding time of the main stellar population TAU_ERR float64 Myr error of the e-folding time of the main stellar population FRACYSSP float64 Myr mass fraction of young stellar population FRACYSSP_ERR float64 Myr error of the mass fraction of young stellar population