DR2 optical value-added catalogue
Description
This is an internal release of working optical ID + value-added catalogue for DR2. For details of the catalogue preparation see Hardcastle et al 2023 (A&A accepted) https://www.extragalactic.info/~mjh/dr2-ids.pdf
Column descriptions for value-added catalogue
Bracketed numbers refer to notes at the end of the file.
| Column | Units | Description |
|---|---|---|
| Source_Name | Object identifier (ILT name) | |
| RA | deg | Radio right ascension (mean position ) |
| DEC | deg | Radio declination (mean position) |
| E_RA | arcsec | Error on radio right ascension |
| E_DEC | arcsec | Error on radio declination |
| Total_flux | mJy | 144-MHz total flux density |
| E_Total_flux | mJy | Error on total flux density |
| Peak_flux | mJy/beam | 144-MHz peak flux density |
| E_Peak_flux | mJy/beam | Error on peak flux density |
| S_Code | PyBDSF source code or Z for composite source | |
| Mosaic_ID | LoTSS mosaic of source image | |
| Maj | arcsec | Major axis of fitted Gaussian |
| Min | arcsec | Minor axis of fitted Gaussian |
| PA | deg | Position angle of fitted Gaussian |
| E_Maj | arcsec | Error on major axis |
| E_Min | arcsec | Error on minor axis |
| E_PA | deg | Error on position angle |
| DC_Maj | arcsec | Deconvolved major axis of fitted Gaussian |
| DC_Min | arcsec | Deconvolved minor axis of fitted Gaussian |
| DC_PA | deg | Deconvolved position angle of fitted Gaussian |
| Isl_rms | mJy/beam | rms noise in island |
| FLAG_WORKFLOW | Flag for workflow status (internal) | |
| ID_flag | Flag for workflow status (internal) (5) | |
| Prefilter | Prefilter status (internal) | |
| Postfilter | Postfilter status (internal) | |
| lr_fin | Final likelihood ratio value (internal) | |
| optRA | deg | Optical right ascension (see Position_from) |
| optDec | deg | Optical declination (see Position_from) |
| Composite_Size | arcsec | Max size of convex hull surrounding components for composite sources |
| Composite_Width | arcsec | Transverse size of convex hull surrounding components for composite sources |
| Composite_PA | deg | Position angle on the sky of longest axis of convex hull |
| Assoc | Number of components used to form composite source | |
| ID_Qual | Quality of association from RGZ(L) | |
| Assoc_Qual | Quality of association from RGZ(L) | |
| Blend_prob | Blend probability from RGZ(L) or manual flagging) | |
| Other_prob | Other problem probability from RGZ(L) | |
| Created | Origin of radio component assignment | |
| Position_from | Origin of optRA, optDec | |
| Renamed_from | Original name e.g. in RGZ if a composite source | |
| ID_RA | deg | Right ascension of positional match in Legacy/WISE crossmatch catalogue |
| ID_DEC | deg | Declination of positional match in Legacy/WISE crossmatch catalogue |
| UID_L | Legacy ID if any | |
| UNWISE_OBJID | UNWISE ID if any | |
| ID_NAME | Legacy ID if present else WISE ID else blank if no ID exists | |
| Separation | Offset between optRA, optDec and ID_RA, ID_DEC (non-zero only for visual inspection) | |
| Legacy_ID | Unique source ID combining release, brick ID and objid | |
| HPX | Healpix of Legacy brick (internal) | |
| release | Legacy release number | |
| brickid | Legacy brick ID | |
| objid | Legacy object ID | |
| maskbits | bitwise mask indicating that an object touches a pixel in the coadd/*/*/*maskbits* maps, as catalogued on the DR8 bitmasks page |
|
| fracflux_g | Profile-weighted fraction of the flux from other sources divided by the total flux in g (typically [0,1]) | |
| fracflux_r | Profile-weighted fraction of the flux from other sources divided by the total flux in r (typically [0,1]) | |
| fracflux_z | Profile-weighted fraction of the flux from other sources divided by the total flux in z (typically [0,1]) | |
| type | Morphological model (1) | |
| ra | deg | Right ascension of match in Legacy catalogue |
| dec | deg | Declination of match in Legacy catalogue |
| pstar | Star likelihood based on GMM modelling (type='PSF' sources only) | |
| star | Likely star based on pstar or proper motion (deprecated), blank if no match | |
| ANYMASK_OPT | Bitwise mask set if the central pixel from any image satisfies each condition in any of g, r or z as catalogued on the DR8 bitmasks page | |
| gmmcomp | Gaussian Mixture Model component to which source belongs (and hence the gpz++ class used for prediction) | |
| zphot | Photo-z estimate | |
| zphot_err | Predicted 1-sigma uncertainty on photometric redshift (after magnitude calibration) | |
| var.density | gpz++ predicted variance from density of training set | |
| var.tr.noise | gpz++ predicted variance from noise in training set | |
| var.in.noise | gpz++ predicted variance from noise in fluxes used in prediction | |
| flag_qual | Predicted photo-z quality flag, 0 if bad, 1 if good (2) | |
| zspec_sdss | SDSS spectroscopic redshift if available | |
| zwarning_sdss | 0 if SDSS redshift is good, 1 if bad | |
| plate_sdss | SDSS plate number | |
| mjd_sdss | SDSS MJD | |
| fiberid_sdss | SDSS fibre ID | |
| z_hetdex | HETDEX spectroscopic redshift if available | |
| z_hetdex_conf | HETDEX spectroscopic redshift confidence | |
| hetdex_sourceid | HETDEX source ID | |
| z_desi | DESI spectroscopic redshift if available | |
| z_desi_err | DESI spectroscopic redshift error | |
| desi_sourceid | DESI source ID | |
| 2RXS_ID | ID in 2RXS | |
| XMMSL2_ID | ID in XMM source catalogue | |
| Resolved | Boolean flag to indicate whether source is resolved | |
| LAS | arcsec | Estimate of angular size, only valid for sources with Resolved == True |
| LAS_from | Source for the LAS column | |
| z_best | Spec-z if available and good, else photo-z if available and good, else blank (3) | |
| z_source | String describing origin of z_best | |
| Size | kpc | LAS times angular size distance (4) |
| L_144 | W/Hz | Radio luminosity in W/Hz for alpha=0.7 (4) |
| LM_size | arcsec | Size from LoMorph code |
| LM_flux | mJy | Flux density from LoMorph code |
| Bad_LM_flux | Flag to say that LoMorph flux is bad | |
| Bad_LM_image | Flag to say that LoMorph mask is bad | |
| Field | Which of the two fields the data come from | |
| Legacy_Coverage | Flag to say whether source is in the DESI Legacy sky area | |
| mag_g | mag | Magnitude in g-band |
| magerr_g | mag | Magnitude error in g-band, or blank for upper limit |
| mag_r | mag | Magnitude in r-band |
| magerr_r | mag | Magnitude error in r-band, or blank for upper limit |
| mag_z | mag | Magnitude in z-band |
| magerr_z | mag | Magnitude error in z-band, or blank for upper limit |
| mag_w1 | mag | Magnitude in WISE band 1 |
| magerr_w1 | mag | Magnitude error in WISE band 1, or blank for upper limit |
| mag_w2 | mag | Magnitude in WISE band 2 |
| magerr_w2 | mag | Magnitude error in WISE band 2, or blank for upper limit |
| mag_w3 | mag | Magnitude in WISE band 3 |
| magerr_w3 | mag | Magnitude error in WISE band 3, or blank for upper limit |
| mag_w4 | mag | Magnitude in WISE band 4 |
| magerr_w4 | mag | Magnitude error in WISE band 4, or blank for upper limit |
| WISE_Src | Origin of the WISE measurements | |
| Mass_median | dex(solMass) | Mass estimate |
| Mass_l68 | dex(solMass) | 68% lower confidence bound on mass |
| Mass_u68 | dex(solMass) | 68% upper confidence bound on mass |
| g_rest | mag | Rest-frame g-band magnitude from SED fit |
| r_rest | mag | Rest-frame r-band magnitude from SED fit |
| z_rest | mag | Rest-frame z-band magnitude from SED fit |
| U_rest | mag | Rest-frame U-band magnitude from SED fit |
| V_rest | mag | Rest-frame V-band magnitude from SED fit |
| J_rest | mag | Rest-frame J-band magnitude from SED fit |
| K_rest | mag | Rest-frame K-band magnitude from SED fit |
| w1_rest | mag | Rest-frame WISE band-1 magnitude from SED fit |
| w2_rest | mag | Rest-frame WISE band-1 magnitude from SED fit |
| flag_mass | True if a mass is measured and reliable | |
| r_50 | arcsec | Half-light radius of Legacy optical exponential/DeVaucouleurs/composite model |
| r_50_err | arcsec | 1-sigma uncertainty on r_50 |
Notes
type- "PSF"=stellar, "REX"="round exponential galaxy", "DEV"=deVauc, "EXP"=exponential, "COMP"=composite, "DUP"=Gaia source fit by different modelflag_qual- Sources with reliable redshifts, with reasonable uncertainty, minimal contamination from nearby sources, low star-likelihood and free from imaging artefacts based onmaskbits- Non-blank
z_bestcombines SDSS/HETDEX or other spec-z with reliable photo-z. - Cosmology is flat Lambda-CDM with H_0 = 70 km/s/Mpc, Omega_M=0.3.
ID_flagdescribes where the ID is from in detail, and is as in the table below:
| Flag value | Meaning |
|---|---|
| -99 | Outside Legacy optical coverage |
| 0 | no ID |
| 1 | LR ID |
| 2 | Match with large optical galaxy |
| 3 | ID from RGZ(L) |
| 5 | Faint source not visually inspected |
| 6 | Sent for deblend |
| 7 | Sent to too-zoomed-in |
| 8 | Uncatalogued host after prefilter |
| 9 | Automatic or visually selected deblend |
| 10 | Blend workflow |
| 11 | Second blend workflow |
| 12 | Too zoomed in workflow |
| 14 | Deduplicate workflow |