Speakers
Description
Throughout SDSS-III and -IV, multiple pipelines have been developed to extract stellar properties from APOGEE spectra. Among them, APOGEE Net stands out due to: a) its speed, and b) the ability to predict stellar parameters (such as Teff, logg, and Fe/H) for all stars with Teff ranging between 3,000 and 50,000 K, including pre-main sequence stars, OB stars, main sequence dwarfs, and red giants, - all as a part of a single model, in a self-consistent manner. With the transition to SDSS-V, a number of spectra of stars will be observed not just with APOGEE in near-IR, but also with BOSS in optical regime. We aim to develop a complementary model, BOSS Net, that will replicate the performance of APOGEE Net in these optical data through label transfer. Although current overlap between sources observed with APOGEE \& BOSS is limited, this can be achieved using LAMOST as an intermediary, as this instrument is similar to BOSS in terms of its wavelength coverage and resolution. We further improve the model through extending it to brown dwarfs, as well as white dwarfs, resulting in a comprehensive coverage between 1700<Teff<100,000 K and 0<logg<10, to ensure BOSS Net can reliably measure parameters of all stellar objects observed by both BOSS and LAMOST. We also update APOGEE Net to achieve a comparable performance in near IR. The resulting models provide a robust tool for measuring stellar evolutionary states, and in turn, enable characterization of the star forming history of the Galaxy.
