Parameters from Spectroscopic Fitting
For most objects, SDSS processing pipelines find estimates of the physical parameters most likely to have produced the observed spectrum. Many different estimates are available - the right one to use will depend on the problem at hand.
Click on the name of each set of estimates for more information on the pipeline that produced those estimates (opens in a new window). Most objects will have either estimated stellar parameters or galaxy properties, but a few objects will have both.
Stellar Parameters
Targeting criteria | GAL | SEGUE flags | VnnnR | HAMMER spectral type | K4 | Spectral subclass | 00 | Radial velocity (km/s) | -9999.0 | RV error | -9999.00 | Effective temp (K) | -9999 | Teff error | -9999 | [Fe/H] (dex) | -9999.0 | [Fe/H] error | -9999.00 | log10(g) (dex) | -9999.0 | log10(g) error | -9999.00 |
Star Forming Model
Best-fit log10(stellar mass) | 11.16 | 1-σ min | 11 | 1-σ max | 11.64 | Best-fit age (Gyr) | 2 | 1-σ min Age | 1.1391 | 1-σ max Age | 9.75 | Best-fit SFR (M☉ / yr) | 0.9 | 1-σ min SFR | 0 | 1-σ max SFR | 1.2 |
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Passive Model
Best-fit log10(stellar mass) | 11.33 | 1-σ min | 11.3 | 1-σ max | 11.38 | Best-fit age (Gyr) | 3.25 | 1-σ min Age | 3 | 1-σ max Age | 3.75 | Best-fit SFR (M☉ / yr) | 0 | 1-σ min SFR | 0 | 1-σ max SFR | 0 |
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Stellar velocity (km/s) | Stellar velocity disperson (km/s) | Velocity dispersion error | Chi-squared fit of template | BPT classification | 85197.23 | 262.662 | 21.099 | 1.29262 | Composite |
Assuming model spectra from Bruzal & Charlot (2003)
Best-fit log10(stellar mass) | Error | Median veldisp (km/s) | Error VelDisp | 11.68 | 0.114 | 347.79 | 36.791 |
Assuming model spectra from Maraston & Strömback (2011)
Best-fit log10(stellar mass) | Error | Median veldisp (km/s) | Error VelDisp | 11.64 | 0.093 | 341.68 | 38.891 |
Early Galaxy Formation,Dust Attenuation
Best-fit log10(stellar mass) | Error | Age (Gyr) | SSFR | metallicity | 11.87 | 0.055 | 6.41 | -2.28 | 0.01 |
Early Galaxy Formation,No Dust Attenuation
Best-fit log10(stellar mass) | Error | Age (Gyr) | SSFR | metallicity | 11.80 | 0.027 | 7.06 | -2.48 | 0.02 |
Wide Range of Formation Times, Dust Attenuation
Best-fit log10(stellar mass) | Error | Age (Gyr) | SSFR | metallicity | 11.89 | 0.089 | 5.76 | -2.08 | 0.01 |
Wide Range of Formation Times,No Dust Attenuation
Best-fit log10(stellar mass) | Error | Age (Gyr) | SSFR | metallicity | 11.80 | 0.039 | 7.06 | -2.48 | 0.02 |
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