APOGEE DR12 Status/Discussion

Schedule Nominal DR12 deadline is July 31, i.e. tomorrow SDSS-III upper level management was consulted about a small delay to take advantage of feedback from this meeting. Adam Bolton: – “From July 31 to August 31, the schedule impact of this goes more or less linearly from "no big deal" to "we're totally hosed". By "we're totally hosed", I mean that we will be forced to choose between either leaving APOGEE out of DR12 CAS or delaying the whole of DR12 significantly.” Practical deadline perhaps 8/15

DR12 products to be delivered SAS – All raw and intermediate data files – Final summary: allStar, allVisit files Data model for parameters/abundances: – FPARAM, PARAM, TEFF, LOGG – FELEM, ELEM (in native FERRE) + X_H SASDB (allows web/API interface to SAS files) – Populated from apField, aspcapField files CAS – Datamodel for abundances: translate arrays into prefexed parameters, have named parameters for TEFF, LOGG, abundances FPARAM_TEFF, FPARAM_LOGG, FPARAM_M_H, etc., PARAM_..., TEFF, LOGG FELEM_X_[MH], ELEM_X_[MH], X_H, …. – Populated from allStar, allVisit files DR12 web pages Datamodel complete and up-to-date

Focus: key issues Current set of files exists – Reduction/star combination final (?!) – ASPCAP will be rerun, but test files exist for proposed final run – Files need to be checked for datamodel, implementation errors/issues Is there anything significantly wrong with basic contents of current files: bar needs to be high to modify significantly (OK to modify calibration decisions) Issues – Calibrations to apply – Flags to apply – Discussion/documentation issues: What do we say about quality/usability for individual elements Unexpected abundance trends in some elements More S/N sensitivity than expected

Scope/analysis New reductions of all data taken to date – Reduction version r5 has improved telluric, etc. – Includes apo25m commissioning/survey + apo1m ASPCAP analysis – ASPCAP configuration l23 December 2013 linelist (not quite latest: incorrect treatment of Sun when deriving astrophysical gf) ASSET synthesis using solar isotope ratio Same grid dimensions/spacing as DR10 lsfcombo5 LSF: average of fibers 50,100,150,200,250 speclib bundling of libraries – 7d analysis of calibration subsample (parameters only), from which logg-vmicro relation is derived to construct 6d library – 6d library run on calibration subsample – Calibrations derived from 6d results of calibration sample – 6d library run on full sample, applying calibrations

microturbulence Proposed relation: linear fit as f(log g) – Similar to DR10 relation – Dwarfs are hitting bottom edge of microturbulence dimesion – Fit derived from giants only Cluster parameters appear very similar using adopted relation

Calibration Raw ASPCAP data probably needs to be “calibrated” for some quantities – DR10: calibrated Teff, logg, [M/H] DR12 proposal – Teff: calibrate using photometric (GHB) temperatures for stars with well-measured extinctions/temperatures: functional dependence? – Logg: calibrated using Kepler sample of RGB stars, as f(log g) – Other “intermediate” parameters: no calibration – Elemental abundances: “internal” calibration: correction as f(Teff) to minimize trends of abundance of each element within clusters (no C or N) “external” calibration – Attempting to have all data/routines used for calibration archived within SDSS software product idlwrap

Teff calibration TBD

Log g calibration via Kepler asteroseismic gravities

Abundances: internal calibration Small trends of abundance with temperature seen for some elements within clusters Propose to fit this trend with metallicity- dependent slope – Linear relation – Slope frozen outside of specified metallicity range Is this a good idea? – Is linear trend OK?

Cluster plots Full sample plots

Uncertainties in abundances Propose to fit scatter within clusters as f(Teff,[M/H],S/N) with linear relations, truncated outside of calibration range Needs checking Need decision on “raw” uncertainty computation from FERRE; do any options provide meaningful errors in regimes of large uncertainty (e.g. non-detections)?

Abundances: external calibration Challenge: lack of external calibration samples for individual elements [Fe/H] suggests trends similar to those seen in [M/H] for DR10: relatively accurate around solar but off by ~0.2 dex at low metallicity – Should we correct this? – Issue: if we correct [Fe/H], then when people look at [X/Fe], they will all be shifted at low metallicity – What to do for other elements? External cal plots

DR12 products SAS – All raw and intermediate data files – Final summary: allStar, allVisit files Data model for parameters/abundances: – FPARAM, PARAM, TEFF, LOGG – FELEM, ELEM (in native FERRE) + X_H SASDB (allows web/API interface to SAS files) – Populated from apField, aspcapField files CAS – Datamodel for abundances: translate arrays into prefexed parameters, have named parameters for TEFF, LOGG, abundances FPARAM_TEFF, FPARAM_LOGG, FPARAM_M_H, etc., PARAM_..., TEFF, LOGG FELEM_X_[MH], ELEM_X_[MH], X_H, …. – Populated from allStar, allVisit files DR12 web pages Datamodel complete and up-to-date

Work session Task list for checks Summary files: allStar, allVisit – Compare uncalibrated vs calibrated (calibrations applied correctly?) – Play with all quantities! DR12 documentation – All pages up-to-date – Description/discussion of abundances Datamodel – Complete and up-to-date? – All SAS files should be in datamodel: but start with most important ones!

Other open issues Hot stars: hot grid not currently implemented; F grid goes to 8000, but with 6D fits Low metallicity stars Dwarfs: generally poor results

Other versions V304 (DR10) V402 (DR11): extend DR10 to year 1+2, flat files have first cut at 9 elements V500: first cut 15 elements casset: new version synthetic libraries with self-consistent atmospheres l22_6d: new reductions  v600 (DR12): with calibrationsdr12