LoTSS Deep Fields DR1 Spectroscopic Source Classifications with DESI DR1 for ELAIS-N1
Description
This catalogue presents a new probabilistic spectroscopic classification scheme based on two methods - the BPT-NII (for the subset where all the necessary lines are available) and the MEx classification (based on a modified version of the well-known Mass Excitation diagram) for all sources where both Hbeta and [OIII] are detectable. The results for the two schemes are identified based on the "_BPT" and "_MEx" subscripts. The BPT classification is similar to the one presented in Drake et al. (2024), where a radio-excess (based on the dust-corrected Halpha luminosity) and BPT-NII diagnostic are used in a probabilistic manner (however here we use the line from Cid Fernandes et al. 2010 to distinguish between LINERs and Seyferts) to classify sources into star forming galaxy (SFG), radio-quiet (RQ) AGN, low-excitation (LERG) and and high-excitation radio galaxy (HERG). The modified MEx classification extends this scheme to z~1, where a radio excess diagnostic (based on the Hbeta flux and dust extinction from Prospector) and the modified MEx diagram are used. For additional information, see Arnaudova et al. (2025).
Column Definitions
| Column | Units | Description |
|---|---|---|
| source_name | Object identifier (ILT name) | |
| targetid | DESI target ID | |
| RA | deg | Right ascension of the DESI target |
| DEC | deg | Declination of the DESI target |
| z | Redshift value from DESI | |
| n_gauss | Number of Gaussian components used for the emission line fitting | |
| r_50 | arcsec | The half-light radius from the Legacy Survey |
| S150 | W\/Hz | 150 MHz total flux density |
| S150_err | W\/Hz | 150 MHz total flux density uncertainty |
| stellar_mass_p16 | solar mass | 16th percentile stellar mass from Das et al. (2024) |
| stellar_mass_p50 | solar mass | 50th percentile stellar mass from Das et al. (2024) |
| stellar_mass_p84 | solar mass | 84th percentile stellar mass from Das et al. (2024) |
| Av_Balmer | magnitudes | Maximum likelihood total extinction as calculated from the Halpha and Hbeta Balmer decrement |
| Av_phot_p16 | mag | 16th percentile Av estimate from Prospector |
| Av_phot_p50 | mag | 50th percentile Av estimate from Prospector |
| Av_phot_p84 | mag | 84th percentile Av estimate from Prospector |
| flux_Hb_4861 | 10^-17 erg/s/cm^2 | Hbeta line flux |
| flux_Hb_4861_err | 10^-17 erg/s/cm^2 | Hbeta line flux uncertainty |
| flux_OIII_5007 | 10^-17 erg/s/cm^2 | [O III] 5007 line flux |
| flux_OIII_5007_err | 10^-17 erg/s/cm^2 | [O III] 5007 line flux uncertainty |
| flux_NII_6583 | 10^-17 erg/s/cm^2 | [N II] 6583 line flux |
| flux_NII_6583_err | 10^-17 erg/s/cm^2 | [N II] 6583 line flux uncertainty |
| flux_Ha_6563 | 10^-17 erg/s/cm^2 | Halpha line flux |
| flux_Ha_6563_err | 10^-17 erg/s/cm^2 | Halpha line flux uncertainty |
| aper_corr | Aperture correction based on the total-to-fibre r-band flux ratio | |
| Class_MP | The most probable (best guess) classification, where SFG=1, RQAGN=2, LERG=3, HERG=4 and Unclassified=-1 | |
| Class_50 | Classification using a 50\% reliability threshold, where SFG=1, RQAGN=2, LERG=3, HERG=4 and Unclassified=-1 | |
| Class_90 | Classification using a 90\% reliability threshold, where SFG=1, RQAGN=2, LERG=3, HERG=4 and Unclassified=-1 | |
| Class_SFG_BPT | Probability of source classification being a SFG based on the radio excess and BPT diagnostic | |
| Class_RQAGN_BPT | Probability of source classification being a RQ AGN based on the radio excess and BPT diagnostic | |
| Class_LERG_BPT | Probability of source classification being a LERG based on the radio excess and BPT diagnostic | |
| Class_HERG_BPT | Probability of source classification being a HERG based on the radio excess and BPT diagnostic | |
| Class_SFG_MEx | Probability of source classification being a SFG based on the radio excess and MEx diagnostic | |
| Class_RQAGN_MEx | Probability of source classification being a RQ AGN based on the radio excess and MEx diagnostic | |
| Class_LERG_MEx | Probability of source classification being a LERG based on the radio excess and MEx diagnostic | |
| Class_HERG_MEx | Probability of source classification being a HERG based on the radio excess and MEx diagnostic | |
| BPT_SFG | Probability of a source having line ratios within the SFG region of the BPT diagram | |
| BPT_CLIN | Probability of a source having line ratios within the composite LINER (CLIN) region of the BPT diagram | |
| BPT_CSeyf | Probability of a source having line ratios within the composite Seyfert (CSeyf) region of the BPT diagram | |
| BPT_LIN | Probability of a source having line ratios within the LINER region of the BPT diagram | |
| BPT_Seyf | Probability of a source having line ratios within the Seyfert region of the BPT diagram | |
| MEx_SFG | Probability of a source having line ratios and a stellar mass within the SFG region of the BPT diagram | |
| MEx_CLIN | Probability of a source having line ratios and a stellar mass within the composite LINER (CLIN) region of the BPT diagram | |
| MEx_CSeyf | Probability of a source having line ratios and a stellar mass within the composite Seyfert (CSeyf) region of the BPT diagram | |
| MEx_LIN | Probability of a source having line ratios and a stellar mass within the LINER region of the BPT diagram | |
| MEx_Seyf | Probability of a source having line ratios and a stellar mass within the Seyfert region of the BPT diagram | |
| RX | Probability of source a having a radio excess, i.e. that the 150 MHz to the Halpha luminosity ratio is larger than predicted values for 99\% of SFGs in the entire sample. | |
| RX_warning_frac | The fraction of realisations for which "poorly-behaved values" occur in the RX diagnostic | |
| BPT_warning_frac | The fraction of realisations for which "poorly-behaved values" occur in the BPT diagnostic | |
| MEx_warning_frac | The fraction of realisations for which "poorly-behaved values" occur in the MEx diagnostic | |
| zscore_BPT | z-score for the maximum-likelihood classification from the BPT diagnostic | |
| zscore_MEx | z-score for the maximum-likelihood classification from the MEx diagnostic | |
| ML_BPT | Maximum likelihood classification from BPT diagnostic ('Unc' = unclassified) | |
| ML_MEx | Maximum likelihood classification from MEx diagnostic ('Unc' = unclassified) |