Bibcode
Troup, N. W.; Nidever, David L.; De Lee, Nathan; Carlberg, Joleen; Majewski, Steven R.; Fernandez, Martin; Covey, Kevin; Chojnowski, S. Drew; Pepper, Joshua; Nguyen, Duy T.; Stassun, Keivan; Nguyen, Duy Cuong; Wisniewski, John P.; Fleming, Scott W.; Bizyaev, Dmitry; Frinchaboy, Peter M.; García-Hernández, D. A.; Ge, Jian; Hearty, Fred; Meszaros, Szabolcs; Pan, Kaike; Allende Prieto, C.; Schneider, Donald P.; Shetrone, Matthew D.; Skrutskie, Michael F.; Wilson, John; Zamora, O.
Bibliographical reference
The Astronomical Journal, Volume 151, Issue 3, article id. 85, 25 pp. (2016).
Advertised on:
3
2016
Citations
49
Refereed citations
48
Description
In its three years of operation, the Sloan Digital Sky Survey Apache
Point Observatory Galactic Evolution Experiment (APOGEE-1) observed
>14,000 stars with enough epochs over a sufficient temporal baseline
for the fitting of Keplerian orbits. We present the custom orbit-fitting
pipeline used to create this catalog, which includes novel quality
metrics that account for the phase and velocity coverage of a fitted
Keplerian orbit. With a typical radial velocity precision of
∼100–200 m s‑1, APOGEE can probe systems with
small separation companions down to a few Jupiter masses. Here we
present initial results from a catalog of 382 of the most compelling
stellar and substellar companion candidates detected by APOGEE, which
orbit a variety of host stars in diverse Galactic environments. Of
these, 376 have no previously known small separation companion. The
distribution of companion candidates in this catalog shows evidence for
an extremely truncated brown dwarf (BD) desert with a paucity of BD
companions only for systems with a\quad \lt 0.1–0.2 AU, with no
indication of a desert at larger orbital separation. We propose a few
potential explanations of this result, some which invoke this
catalog’s many small separation companion candidates found
orbiting evolved stars. Furthermore, 16 BD and planet candidates have
been identified around metal-poor ([Fe/H] <‑0.5) stars in this
catalog, which may challenge the core accretion model for companions \gt
10{M}{Jup}. Finally, we find all types of companions are
ubiquitous throughout the Galactic disk with candidate planetary-mass
and BD companions to distances of ∼6 and ∼16 kpc, respectively.