glossary for ECO DR3 searchable online database
ECO DR3 includes parameters from previous data releases by crossmatch unless obsolete or superseded. Users may refer to ECO DR1-DR2 for the original data. Please note that there have been changes to survey membership. Additionally, Hutchens et al. (2023) rejected some photometry from calculations. These magnitudes are reported as -999 in the main data table, but the full photometry can be accessed with this CSV file. The rejected photometry can also be accessed in the ECO DR3 photometry table on our Data page.
| parameter | unit | description |
|---|---|---|
| 2hmag | mag | Apparent 2MASS H-band magnitude (provided without foreground extinction corrections) |
| 2jmag | mag | Apparent 2MASS J-band magnitude (provided without foreground extinction corrections) |
| 2kmag | mag | Apparent 2MASS K-band magnitude (provided without foreground extinction corrections) |
| absrmag | mag | Absolute magnitude in SDSS r Band (matching RESOLVE-A for shared galaxies), please refer to badrphot when using this column |
| absrmagcorr | mag | absolute r-band magnitude including correction for internal extinction (foreground corrections and k-corrections implicitly included), consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| absrmage16 | mag | Absolute magnitude in SDSS r band from E16 (foreground extinction corrections included) |
| agcnr_a100 | --- | Name of crossmatched source in ALFALFA-100 (Arecibo General Catalog Number) |
| b_a | --- | axial ratio b/a |
| badrphot | --- | Bad r-band photometry flag from H23, marking galaxies for which effective radii were previously set to arbitrary or negative values due to pipeline failures. 0 = No r-band photometry issue, 1 = bad but usable r-band |
| ccbremapped | --- | Boundary completeness correction factor remapped to G3 groups as in H23 |
| confused | --- | Confusion flag from ALFALFA-100 or from RESOLVE-A |
| confused_a100 | --- | Confusion flag from ALFALFA-100 crossmatch |
| cz | km/s | Local Group-corrected Recession Velocity of Galaxy (matching RESOLVE-A for shared galaxies) |
| cze16 | km/s | Local Group-corrected Recession Velocity of Galaxy from E16 |
| czhel | km/s | Heliocentric Recession Velocity of Galaxy (matching RESOLVE-A for shared galaxies) |
| dedeg | deg | Declination of photometric center in decimal degrees |
| e_2hmag | mag | Error in 2Hmag |
| e_2jmag | mag | Error in 2Jmag |
| e_2kmag | mag | Error in 2Kmag |
| e_gmag | mag | Error in gmag |
| e_imag | mag | Error in imag |
| e_nuvmag | mag | Error in NUVmag |
| e_uhmag | mag | Error on uhmag |
| e_ukmag | mag | Error on uhmag |
| e_umag | mag | Error in umag |
| e_uymag | mag | Error on uymag |
| e_zmag | mag | Error in zmag |
| emhidet | Msun | Statistical uncertainty on HI masses in mhidet |
| emhidet_a100 | Msun | Statistical uncertainty on mhidet_a100 |
| ev50_a100 | km/s | Statistical uncertainty on systematic velocity from ALFALFA-100 |
| extg | mag | Foreground extinction in r band |
| exth | mag | Foreground extinction in 2MASS and UKIDSS H bands |
| exti | mag | Foreground extinction in i band |
| extj | mag | Foreground extinction in 2MASS J band |
| extk | mag | Foreground extinction in 2MASS and UKIDSS K bands |
| extnuv | mag | Foreground extinction in NUV band |
| extr | mag | Foreground extinction in r band |
| extu | mag | Foreground extinction in u band |
| exty | mag | Foreground extinction in UKIDSS Y Band |
| extz | mag | Foreground extinction in z band |
| fm15 | --- | 1/0 flag for objects used in the Moffett+2015 |
| foffc | --- | FoF central galaxy flag (1 for most luminous group member in r band) |
| fofgrp | --- | FoF group identifier from H23 |
| fofgrpabsrmag | mag | FoF group-integrated absolute r-band magnitude (giants & dwarfs) |
| fofgrpcz | km/s | FoF group center cz |
| fofgrpdedeg | deg | FoF group center Declination J2000 |
| fofgrpmhi | log(Msun) | FoF log group-integrated HI mass from H23 |
| fofgrpn | --- | Number of galaxies in FoF group |
| fofgrpradeg | deg | FoF group center RA J2000 |
| foflogmh200 | log(Msun) | FoF log group halo mass using Warren et al. (2006) HMF. -- WARNING: This column is mislabeled as the Warren et al. HMF uses an overdensity contrast of 280b, not 200b. An erratum for H23 will be issued soon. |
| foflogmhvir | log(Msun) | FoF log group halo mass (337b) |
| g3fc | --- | G3 central galaxy flag (1 for most luminous group member in r band) |
| g3grp | --- | G3 group identifer |
| g3grpabsrmag | mag | G3 group-integrated absolute r-band magnitude (giants & dwarfs) |
| g3grpcz | km/s | G3 group center cz |
| g3grpdedeg | deg | G3 group center Declination J2000 |
| g3grpgiantabsrmag | mag | G3 group-integrated giant galaxy absolute r-band magnitude |
| g3grpmhi | log(Msun) | G3 log group-integrated HI mass |
| g3grpndw | --- | Number of dwarf galaxies in G3 group |
| g3grpngi | --- | Number of giant galaxies in G3 group |
| g3grpradeg | deg | G3 group center RA J2000 |
| g3logmh200 | log(Msun) | G3 log group halo mass using Warren et al. (2006) HMF. -- WARNING: This column is mislabeled as the Warren et al. HMF uses an overdensity contrast of 280b, not 200b. An erratum for H23 will be issued soon. |
| g3logmhvir | log(Msun) | G3 log group halo mass (337b) |
| gmag | mag | Apparent SDSS g-band magnitude (provided without foreground extinction corrections) |
| hirms | --- | RMS noise level of HI spectra; these are measured directly from spectra within the RESOLVE-A region. Outside RESOLVE-A, they are (a) estimated from declination for upper limits or (b) sourced from the ALFALFA catalog for detections. 0 if the galaxy was not covered by ALFALFA or RESOLVE-A. |
| hirms_a100 | Jy | RMS noise level of HI spectra, extracted from public ALFALFA-100 catalog for detections, and estimated from declination for upper limits. |
| hitelescope | --- | Telescope or survey used to obtain the HI detection or upper limit. |
| imag | mag | Apparent SDSS i-band magnitude (provided without foreground extinction corrections) |
| invole17 | --- | Group in-volume flag for E17 groups (1 if 3000 < cz_grp < 7000) |
| involfof | --- | Group in-volume flag for H23 FoF groups (1 if 3000 < cz_grp < 7000) |
| involg3 | --- | Group in-volume flag for G3 groups (1 if 3000 < cz_grp < 7000) |
| limmult | --- | Scalar multiplier by which to scale an upper limit mass (mhilim) from `limsigma`. We use a value of X=3 within the RESOLVE-A region, where HI signals are extracted with the optical position known as a prior. Outside RESOLVE-A, we use X=5 to characterize upper limit masses for what would have been a blind detection. |
| limsigma | Msun | 21 cm mass “uncertainty” for non-detections, σ_M, based on estimated RMS noise level and estimated W20 linewidth. 0 for detections. Related to mhilim by mhilim = X*σ_M. |
| logmgas | log(Msun) | Log gas mass (1.4*MHI to account for He); this gas mass is the "best" as it combines good HI measurements and PGFs. Follows algorithm described in A.6.2 of H23 (not the E16 algorithm) |
| logmgas_a100 | log(Msun) | Log gas mass (1.4*MHI to account for He); this gas mass is the "best" as it combines good HI measurements and PGFs. Follows algorithm described in A.6.2 of H23 (not the E16 algorithm) |
| logmgastype | --- | logmgas type flag, see H23 A.6.2 for description of values |
| logmgastype_a100 | --- | logmgas type flag, see H23 A.6.2 for description of values |
| logmstar | log(Msun) | Log stellar mass, consistent with SED modeling code updates described in E15 Erratum and H23 appendix. Please refer to `badrphot` when using this column. |
| loscmvgdist | Mpc | Line-of-Sight Comoving Distance to Galaxy |
| mhidet | Msun | HI masses from ALFALFA-100 21cm detections or inherited from RESOLVE HI census if in the RESOLVE-A subregion, assuming H0 = 70 (km/s)/Mpc; 0 if not detected or not observed |
| mhidet_a100 | Msun | HI masses from ALFALFA-100 21cm detections assuming H0 = 70 (km/s)/Mpc; 0 if galaxy is upper limit or not observed; no other sources of HI measurements included in this column. |
| mhilim | Msun | Upper limit on HI mass assuming H0 = 70 (km/s)/Mpc. Upper limit masses are computed as X*σ_M, where X is the constant multiplier given by the `limmult` column. Referencing eq. (1) in Stark et al. (2016), σ_M = 2.36e+5(cz/H0)**2(σ_F). 0 if detection or unobserved. |
| mhilim_a100 | Msun | 5-sigma upper limit on HI mass for ALFALFA-100 non-detections; 0 if detection or galaxy outside a100 sky coverage |
| modelabsrmag | mag | Model absolute r-band magnitude, includes foreground extinction corrections and k-corrections, but not internal extinction corrections. |
| modelg_i | mag | SED modeled (g-i) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| modelg_j | mag | SED modeled (g-J) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| modelg_k | mag | SED modeled (g-K) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| modelg_r | mag | SED modeled (g-r) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| modelu_i | mag | SED modeled (u-i) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| modelu_j | mag | SED modeled (u-J) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| modelu_k | mag | SED modeled (u-K) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| modelu_r | mag | SED modeled (u-r) color (foreground corrections and k-corrections implicity included) consistent with SED modeling code updates described in E15 Erratum and H23 appendix |
| morphel | --- | string "E" = early type, "L" = late type for quantitative morphological type (from Moffett+ 2015) "NA" means that mudelta was not measured |
| mu_delta | log(Msun/kpc^2) | stellar surface mass density within R50 minus stellar surface mass density between R50 and R90 (see Kannappan et al. 2013 for details) that corresponds to galaxy morphology; a value of -999 means the r-band photometry was bad (see `badrphot`). |
| name | --- | ECO galaxy identifier |
| nuvmag | mag | Apparent GALEX NUV-band magnitude (provided without foreground extinction corrections) |
| peaksnhi | --- | Peak SNR of 21cm line; SNR of ~>5-6 ideal for reliable W50 |
| peaksnhi_a100 | --- | Peak SNR of HI profile; SNR of >5-6 ideal for reliable W50. |
| r50 | arcsec | The half-light radius in r band, -999 if bad r-band photometry (see `badrphot`) |
| r90 | arcsec | The 90%-light radius in r band, -999 if bad r-band photometry (see `badrphot`) |
| radeg | deg | Right Ascension of photometric center in decimal degrees |
| resname | --- | name of matched galaxy in RESOLVE catalog |
| rmag | mag | Apparent SDSS r-band magnitude (provided without foreground extinction corrections) |
| uhmag | mag | Apparent magnitude in UKIDSS H band (provided without foreground extinction corrections) |
| ukmag | mag | Apparent magnitude in UKIDSS K band (provided without foreground extinction corrections) |
| umag | mag | Apparent SDSS u-band magnitude (provided without foreground extinction corrections) |
| uymag | mag | Apparent magnitude in UKIDSS Y band (provided without foreground extinction corrections) |
| vif | --- | Visual inspection flag from H23 duplicate search |
| zmag | mag | Apparent SDSS z-band magnitude (provided without foreground extinction corrections) |