Column descriptions - hzovaro/spaxelsleuth GitHub Wiki
spaxelsleuth is based on pandas DataFrames, where each row represents a single bin or spaxel. Detailed descriptions of the contents of each column are given below.
In the table, <component> represents which Gaussian emission line component the quantity corresponds to, e.g. "component 1" or "component 2", or it may be "total", in which case the measurement corresponds to the quantity summed over all Gaussian components. <line> represents an emission line name.
| Column | Description |
|---|---|
| ID | Galaxy ID |
| Flags | |
| Good? | Whether galaxy is in final sample |
| Bad class | Flag for bad or problem objects - 0, 5 and 8 are "good" |
| Coordinates | |
| RA (IFU) (J2000) | IFU right ascension in degrees (J2000) |
| RA (J2000) | Object right ascension in degrees (J2000) |
| Dec (IFU) (J2000) | IFU declination in degrees (J2000) |
| Dec (J2000) | Object declination in degrees (J2000) |
| z (spectroscopic) | Spectroscopic redshift |
| z (flow-corrected) | Flow-corrected redshift |
| z | Redshift (flow-corrected, if available, otherwise spectroscopic) |
| D_A (Mpc) | Angular diameter distance |
| D_L (Mpc) | Luminosity distance |
| kpc per arcsec | Angular scale |
| Morphologies | |
| Morphology (numeric) | Galaxy morphology (numerical representation) |
| Morphology | Galaxy morphology (string representation) |
| Masses, magnitudes, surface brightnesses, colours | |
| log M_* | Logarithm of stellar mass |
| A_g | g-band extinction |
| M_r | Absolute r-band magnitude |
| g - i colour | g - i colour |
| mu_r at 1R_e | r-band surface brightness at 1 effective radius (Kelvin et al. 2012) |
| mu_r at 2R_e | r-band surface brightness at 2 effective radii (Kelvin et al. 2012) |
| mu_r within 1R_e | Mean r-band surface brightness within 1 effective radius (Kelvin et al. 2012) |
| Sizes, inclinations, etc. from Kelvin et al. (2012) fits | |
| e | r-band ellipticity (Kelvin et al. 2012) |
| PA (degrees) | r-band position angle (Kelvin et al. 2012) |
| R_e (arcsec) | r-band major axis effective radius (Kelvin et al. 2012) |
| R_e (kpc) | Effective radius in kpc (Kelvin et al. 2012) |
| i (degrees) | Inclination (Kelvin et al. 2012) |
| Multi-Gaussian Expansion (MGE) size measurements | |
| R_e (MGE) (arcsec) | Circularised effective radius (MGE fit) |
| m_AB (MGE) | AB magnitude within 1R_e (MGE fit) |
| PA (MGE) (degrees) | Position angle (MGE fit) |
| e at 1R_e (MGE) | Model isophotal ellipticity at one Re (MGE fit) |
| e, LW (MGE) | Light-weighted ellipticity of the model (MGE fit) |
| R_e (MGE) (kpc) | Effective radius in kpc (MGE fit) |
| Environmental metrics | |
| Cluster member | Flag indicating cluster membership (1=member, 0=non-member) |
| r/R_200 | Projected distance from cluster centre normalised by R200 |
| v/sigma_cluster | Line-of-sight velocity relative to cluster redshift normalised by cluster velocity dispersion measured within R200 |
| Proxies for stellar mass surface density/gravitational potential | |
| log(M/R_e) (MGE) | Stellar mass divided by R_e (MGE fit) |
| log(M/R_e^2) (MGE) | Stellar mass divided by R_e^2 (MGE fit) |
| log(M/R_e) | Stellar mass divided by R_e (Kelvin et al. 2012) |
| log(M/R_e^2) | Stellar mass divided by R_e^2 (Kelvin et al. 2012) |
| Spatially resolved quantities | |
| Stellar kinematics | |
| sigma_* | Stellar velocity dispersion (km/s) |
| sigma_* error | 1-sigma uncertainty on stellar velocity dispersion (km/s) |
| v_* | Stellar velocity (km/s) |
| v_* error | 1-sigma uncertainty on stellar velocity (km/s) |
| Continuum-derived properties | |
| HALPHA continuum | Mean continuum level in the rest-frame wavelength range 6500 Å - 6540 Å (flux units) |
| HALPHA continuum std. dev. | Standard deviation in the continuum level in the rest-frame wavelength range 6500 Å - 6540 Å (flux units) |
| HALPHA continuum error | 1-sigma uncertainty on the mean continuum level in the rest-frame wavelength range 6500 Å - 6540 Å (flux units) |
| HALPHA continuum luminosity | Mean continuum luminosity measured in the rest-frame wavelength range 6500 Å - 6540 Å |
| HALPHA continuum luminosity error | 1-sigma uncertainty on the mean continuum luminosity measured in the rest-frame wavelength range 6500 Å - 6540 Å |
| B-band continuum | Mean continuum level in the rest-frame wavelength range 4000 Å - 5000 Å (flux units) |
| B-band continuum std. dev. | Standard deviation in the continuum level in the rest-frame wavelength range 4000 Å - 5000 Å (flux units) |
| B-band continuum error | 1-sigmag uncertainty on the mean continuum level in the rest-frame wavelength range 4000 Å - 5000 Å (flux units) |
| D4000 | Dn4000 break strength using the definition of Balogh et al. (1999) |
| D4000 error | 1-sigma uncertainty on the Dn4000 break strength using the definition of Balogh et al. (1999) |
| Median SNR (B, full field) | Median signal-to-noise ratio in the B data cube measured across all spaxels |
| Median SNR (R, full field) | Median signal-to-noise ratio in the R data cube measured across all spaxels |
| Median SNR (B, 1R_e) | Median signal-to-noise ratio in the B data cube measured within 1R_e (circularised MGE R_e) |
| Median SNR (R, 1R_e) | Median signal-to-noise ratio in the R data cube measured within 1R_e (circularised MGE R_e) |
| Median SNR (B, 1.5R_e) | Median signal-to-noise ratio in the R data cube measured within 1.5R_e (circularised MGE R_e) |
| Median SNR (R, 1.5R_e) | Median signal-to-noise ratio in the R data cube measured within 1.5R_e (circularised MGE R_e) |
| Median SNR (B, 2R_e) | Median signal-to-noise ratio in the B data cube measured within 2R_e (circularised MGE R_e) |
| Median SNR (R, 2R_e) | Median signal-to-noise ratio in the R data cube measured within 3R_e (circularised MGE R_e) |
| Coordinates and geometry | |
| x_0 (arcsec) | x-coordinate of galaxy centre in arcsec relative to bottom-left corner of image |
| y_0 (arcsec) | y-coordinate of galaxy centre in arcsec relative to bottom-left corner of image |
| x (projected, arcsec) | Projected x-coordinate of spaxel (or bin centre) in arcsec relative to bottom-left corner of image |
| y (projected, arcsec) | Projected y-coordinate of spaxel (or bin centre) in arcsec relative to bottom-left corner of image |
| x (relative to galaxy centre, deprojected, arcsec) | De-projected x-coordinate of spaxel (or bin centre) in arcsec relative to galaxy centre |
| y (relative to galaxy centre, deprojected, arcsec) | De-projected y-coordinate of spaxel (or bin centre) in arcsec relative to galaxy centre |
| r (relative to galaxy centre, deprojected, arcsec) | De-projected radius of spaxel (or bin centre) in arcsec relative to galaxy centre |
| Bin number | Spaxel or bin number |
| Bin size (pixels) | Spaxel or bin size (in pixels) |
| Bin size (square arcsec) | Spaxel or bin size (in square arcseconds) |
| Bin size (square kpc) | Spaxel or bin size (in square kpc) |
| r/R_e | De-projected radius of spaxel (or bin centre) in units of R_e (Kelvin et al. 2012) relative to galaxy centre |
| Emission line quantities | |
| Number of components (original) | Number of Gaussian emission line components identified by LZComp in this spaxel or bin |
| Number of components | "Final" number of components after accounting for data quality and S/N cuts |
| <line> (<component>) | <line> flux (flux units) |
| <line> error (<component>) | 1-sigma uncertainty on <line> flux (flux units) |
| <line> S/N (<component>) | <line> S/N, defined as the flux divided by the 1-sigma uncertainty on the flux |
| <line> luminosity (<component>) | <line> luminosity (flux units) |
| <line> luminosity error (<component>) | 1-sigma uncertainty on the <line> luminosity (flux units) |
| HALPHA EW (<component>) | Halpha equivalent width, defined as the Halpha flux divided by the mean continuum leven in the rest-frame wavelength range 6500 Å - 6540 Å |
| HALPHA EW error (<component>) | 1-sigma uncertainty on the Halpha equivalent width, defined as the Halpha flux divided by the mean continuum leven in the rest-frame wavelength range 6500 Å - 6540 Å |
| log HALPHA luminosity (<component>) | Logarithm of the Halpha luminosity (log erg/s) |
| log HALPHA luminosity error (lower) (<component>) | Lower 1-sigma uncertainty on the logarithm of the Halpha luminosity (log erg/s |
| log HALPHA luminosity error (upper) (<component>) | Upper 1-sigma uncertainty on the logarithm of the Halpha luminosity (log erg/s |
| log HALPHA EW (<component>) | Logarithm of the Halpha EW (log Å) |
| log HALPHA EW error (lower) (<component>) | Lower 1-sigma uncertainty on logarithm of the Halpha EW (log Å) |
| log HALPHA EW error (upper) (<component>) | Upper 1-sigma uncertainty on logarithm of the Halpha EW (log Å) |
| Emission line kinematics | |
| v_gas (<component>) | LOS gas velocity (km/s) |
| v_gas error (<component>) | 1-sigma uncertainty on LOS gas velocity (km/s) |
| v_grad (<component>) | Velocity gradient (eqn. 1 of Zhou et al. 2017) |
| sigma_gas (<component> | LOS gas velocity dispersion corrected for instrumental resolution (km/s) |
| sigma_gas error (<component> | 1-sigma uncertainty on LOS gas velocity dispersion corrected for instrumental resolution (km/s) |
| log sigma_gas (<component>) | Logarithm of the gas velocity dispersion corrected for instrumental resolution (log km/s) |
| log sigma_gas error (lower) (<component>) | Lower 1-sigma uncertainty on logarithm of the gas velocity dispersion corrected for instrumental resolution (log km/s) |
| log sigma_gas error (upper) (<component>) | Upper 1-sigma uncertainty on logarithm of the gas velocity dispersion corrected for instrumental resolution (log km/s) |
| sigma_obs (<component>) | Observed velocity dispersion, un-corrected for instrumental resolution (km/s) |
| sigma_obs S/N (<component>) | Velocity dispersion S/N as defined by Federrath et al. (2017) |
| sigma_obs target S/N (<component>) | Target velocity dispersion S/N as defined by Federrath et al. (2017) assuming sigma_gas_SNR_min = 3 |
| FWHM_gas (<component>) | Emission line component FWHM (corrected for instrumental resolution) |
| FWHM_gas error (<component>) | 1-sigma uncertainty on the emission line component FWHM (corrected for instrumental resolution) |
| Star formation rates | |
| SFR (<component>) | SFR (Msun/yr/kpc^-2) |
| SFR error (<component>) | 1-sigma uncertainty on the SFR (Msun/yr/kpc^-2) |
| log SFR (<component>) | Log SFR (<component>) |
| log SFR error (lower) (<component>) | Lower 1-sigma uncertainty on log SFR (<component>) |
| log SFR error (upper) (<component>) | Upper 1-sigma uncertainty on log SFR (<component>) |
| SFR surface density (<component>) | SFR surface density (Msun/yr/kpc^-2) |
| SFR surface density error (<component>) | 1-sigma uncertainty on the SFR surface density (Msun/yr/kpc^-2) |
| log SFR surface density (<component>) | Log SFR surface density (<component>) |
| log SFR surface density error (lower) (<component>) | Lower 1-sigma uncertainty on log SFR surface density (<component>) |
| log SFR surface density error (upper) (<component>) | Upper 1-sigma uncertainty on log SFR surface density (<component>) |
| Other emission line quantities | |
| HALPHA lambda_obs (Å) (<component>) | Observed central wavelength of HALPHA in Angstroms |
| HALPHA sigma_gas (Å) (<component>) | Gaussian sigma of HALPHA in Angstroms |
| HALPHA A (<component>) | Gaussian Amplitude of HALPHA in 'flux units' |
| HALPHA A/N (measured) | Halpha amplitude-to-noise measured directly from the spectrum. Measured as as ... |
| Extinction parameters | |
| HALPHA extinction correction (total) | Halpha extinction correction factor (from SAMI DR3) |
| HALPHA extinction correction error (total) | 1-sigma uncertainty on Halpha extinction correction factor (from SAMI DR3) |
| Balmer decrement (<component>) | Measured HALPHA/HBETA ratio |
| Balmer decrement error (<component>) | 1-sigma uncertainty on the measured HALPHA/ HBETAratio |
| A_V (<component>) | Total extinction in the V-band computed using the Balmer decrement (mag) |
| A_V error (<component>) | 1-sigma uncertainty on the total extinction in the V-band computed using the Balmer decrement |
| Emission line ratios | |
| N2O2 (<component>) | log NII6583 / OII3726+OII3729 ratio |
| N2S2 (<component>) | log NII6583 / SII6716+SII6731 ratio |
| O3N2 (<component>) | log (OIII5007/HBETA) / (NII6583/HALPHA) ratio |
| R23 (<component>) | log (OIII4959+OIII5007 + OII3726+OII3729) / HBETA ratio |
| O3O2 (<component>) | log OIII5007 / OII3726+OII3729 ratio |
| O1O3 (<component>) | log OI6300 / OIII5007 ratio |
| Dopita+2016 (<component>) | log (NII6583 / SII6716+SII6731) + 0.264 * np.log10(NII6583 / HALPHA) ratio |
| N2 (<component>) | NII6583 / HALPHA ratio |
| N2 error (<component>) | 1-sigma uncertainty on the NII6583 / HALPHA ratio |
| log N2 (<component>) | log NII6583 / HALPHA ratio |
| log N2 error (lower) (<component>) | Lower 1-sigma uncertainty on log NII6583 / HALPHA ratio |
| log N2 error (upper) (<component>) | Lower 1-sigma uncertainty on log NII6583 / HALPHA ratio |
| O1 (<component>) | OI6300 / HALPHA ratio |
| O1 error (<component>) | 1-sigma uncertainty on the OI6300 / HALPHA ratio |
| log O1 (<component>) | log OI6300 / HALPHA ratio |
| log O1 error (lower) (<component>) | Lower 1-sigma uncertainty on log OI6300 / HALPHA ratio |
| log O1 error (upper) (<component>) | Lower 1-sigma uncertainty on log OI6300 / HALPHA ratio |
| S2 (<component>) | SII6716+SII6731 / HALPHA ratio |
| S2 error (<component>) | 1-sigma uncertainty on the SII6716+SII6731 / HALPHA ratio |
| log S2 (<component>) | log SII6716+SII6731 / HALPHA ratio |
| log S2 error (lower) (<component>) | Lower 1-sigma uncertainty on log SII6716+SII6731 / HALPHA ratio |
| log S2 error (upper) (<component>) | Upper 1-sigma uncertainty on log SII6716+SII6731 / HALPHA ratio |
| O3 (<component>) | OIII5007 / HBETA ratio |
| O3 error (<component>) | 1-sigma uncertainty on the OIII5007 / HBETA ratio |
| log O3 (<component>) | log OIII5007 / HBETA ratio |
| log O3 error (lower) (<component>) | Lower 1-sigma uncertainty on log OIII5007 / HBETA ratio |
| log O3 error (upper) (<component>) | Upper 1-sigma uncertainty on log OIII5007 / HBETA ratio |
| [SII] ratio (<component>) | SII6716/SII6731 ratio |
| [SII] ratio error (<component>) | 1-sigma uncertainty on the SII6716/SII6731 ratio |
| log [SII] ratio (<component>) | log SII6716/SII6731 ratio |
| log [SII] ratio error (lower) (<component>) | Lower 1-sigma uncertainty on log SII6716/SII6731 ratio |
| log [SII] ratio error (upper) (<component>) | Upper 1-sigma uncertainty on log SII6716/SII6731 ratio |
| Spectral categories | |
| BPT (numeric) (<component>) | BPT category (numerical representation) |
| BPT (<component>) | BPT category (string representation) |
| Stellar/gas kinematic offsets | |
| v_gas - v_* (<component>) | Difference between stellar and gas LOS velocities |
| v_gas - v_* error (<component>) | 1-sigma uncertainty on the difference between stellar and gas LOS velocities |
| sigma_gas - sigma_* (<component>) | Difference between stellar and gas LOS velocity dispersions |
| sigma_gas^2 - sigma_*^2 (<component>) | Difference between the squares of the stellar and gas LOS velocity dispersions |
| sigma_gas/sigma_* (<component>) | Ratio of the stellar and gas LOS velocity dispersions |
| sigma_gas - sigma_* error (<component>) | 1-sigma uncertainty on the difference between stellar and gas LOS velocity dispersions |
| sigma_gas^2 - sigma_*^2 error (<component>) | 1-sigma uncertainty on the difference between the squares of the stellar and gas LOS velocity dispersions |
| sigma_gas/sigma_* error (<component>) | 1-sigma uncertainty on the ratio of the stellar and gas LOS velocity dispersions |
| Component offsets | |
| delta sigma_gas (A/B) | sigma_gas (component A) - sigma_gas (component B) |
| delta sigma_gas error (A/B) | 1-sigma uncertainty on sigma_gas (component A) - sigma_gas (component B) |
| delta v_gas (A/B) | v_gas (component A) - v_gas (component B) |
| delta v_gas error (A/B) | 1-sigma uncertainty on v_gas (component A) - v_gas (component B) |
| HALPHA EW ratio (A/B) | Ratio of EWs measured in components A and B |
| HALPHA EW ratio error (A/B) | 1-sigma uncertainty on ratio of EWs measured in components A and B |
| Delta HALPHA EW (A/B) | log(HALPHA EW (component A)) - log(HALPHA EW (component B)) |
| HALPHA EW/HALPHA EW (total) (<component>) | HALPHA EW in <component> divided by the total EW in the spaxel |
| Metallicities | |
| log(O/H) + 12 (<diagnostic>) (<component>) | Gas-phase metallicity measured using <diagnostic> (<component>) |
| log(O/H) + 12 (<diagnostic>) error (lower) (<component>) | Lower 1-sigma uncertainty on the gas-phase metallicity measured using <diagnostic> (<component>), from MC simulations |
| log(O/H) + 12 (<diagnostic>) error (upper) (<component>) | Upper 1-sigma uncertainty on the gas-phase metallicity measured using <diagnostic> (<component>), from MC simulations |
| log(U) (<diagnostic>) (<component>) | Ionisation parameter measured using <diagnostic> (<component>) |
| log(U) (<diagnostic>) error (lower) (<component>) | Lower 1-sigma uncertainty on the ionisation parameter measured using <diagnostic> (<component>) |
| log(U) (<diagnostic>) error (upper) (<component>) | Upper 1-sigma uncertainty on the ionisation parameter measured using <diagnostic> (<component>) |
| Data quality and S/N settings | |
| eline_SNR_min | Minimum emission line S/N adopted |
| sigma_gas_SNR_min | Minimum gas velocity dispersion S/N adopted |
| line_flux_SNR_cut | True if S/N cuts have been applied to emission line fluxes |
| missing_fluxes_cut | True if missing flux cuts have been applied to emission line fluxes |
| line_amplitude_SNR_cut | True if line amplitude cuts have been applied to emission line fluxes |
| flux_fraction_cut | True if flux fraction cuts have been applied to emission line fluxes |
| vgrad_cut | True if beam smearing cuts have been applied to gas velocity dispersion measurements |
| sigma_gas_SNR_cut | True if S/N cuts have been applied to gas velocity dispersion measurements |
| stekin_cut | True if stellar kinematics data quality and S/N cuts have been applied |
| correct_extinction | True if extinction correction has been applied to emission line fluxes |
| Data quality and S/N flags | |
| Beam smearing flag (<component>) | True if sigma_gas < 2 * v_grad |
| Low sigma_gas S/N flag (<component>) | True if sigma_obs S/N < sigma_obs target S/N |
| Bad stellar kinematics | True if stellar kinematics do not meet the minimum data quality and S/N requirements given in Croom et al. (2021) (p18) |
| Low flux S/N flag - <line> (<component>) | True if <line> S/N < eline_SNR_min |
| Missing flux flag - <line> (<component>) | True if <line> flux is NaN but the corresponding error is finite |
| Missing v_gas flag (<component>) | True if v_gas flag (<component>) is NaN but the corresponding error is finite |
| Missing sigma_gas flag (<component>) | True if sigma_gas flag (<component>) is NaN but the corresponding error is finite |
| Missing v_* flag | True if v_* flag is NaN but the corresponding error is finite |
| Missing sigma_* flag | True if sigma_* flag is NaN but the corresponding error is finite |
| Low flux fraction flag - <line> (<component>) | True if <line> amplitude (<component>) < 0.05 * <line> amplitude (component 1) |
| Low amplitude flag - <line> (<component>) | True if <line> (<component>) < 3 * RMS noise in the rest-frame wavelength range |
| Missing components flag (<component>) | True if any kinematic components in this spaxel fail to meet minimum data quality and S/N requirements |