This page relays a list of known issues in the DR15 APOGEE data release. We have separated these into two categories: (i) problems and bugs and (ii) fundamental limitations from either data or methodology. The former are known issues in the catalogs themselves (many discovered after the release), whereas the latter are more fundamental to what we can provide.
Problems and Bugs
VHELIO is in Barycentric Frame
Target bit not set
- 22 -- APOGEE2_1M_TARGET
- 23 -- APOGEE2_MOD_BRIGHT_LIMIT
- 30 -- APOGEE2_OBJECT
This will be corrected in future releases.
logg Calibration for RC stars
Users are encouraged to recalibrate their data for all RC stars following the updated calibration relations described in the External Calibration section of the ASPCAP documentation.
The EXTRATARG bit should allow users to avoid the duplicate use of the same target in an analysis.
Multiple target classes
Y is Misidentified
Invalid C and N abundances in dwarfs
Users should not use C and N abundances for stars fit with the dwarf grids (ASPCAP_CLASS = Fd, GKd, or Md)!
All of the caveats listed on this page apply to the Cannon results. Unfortunately, there is no way for the user to recalibrate the Cannon results.
Users should not use any results for stars with log g > 2.9 due to the problem with the ASPCAP surface gravity calibration.
Methodology and Data Limitations
Lingering effects of LSF
Erroneous extinctions for bright stars
Users are cautioned against using the tabulated extinctions for very bright stars.
Persistent effects of persistence
Users of the APOGEE spectra should pay careful attention to the persistence flags and should consider the use of the inflated uncertainties for persistence-affected pixels. .
Atypical Abundance Ratios
SNREV is the recommended quantity to use for S/N assessment.