TY - JOUR
T1 - Analysis of the Full Spitzer Microlensing Sample. I. Dark Remnant Candidates and Gaia Predictions
AU - Rybicki, Krzysztof A.
AU - Shvartzvald, Yossi
AU - Yee, Jennifer C.
AU - Novati, Sebastiano Calchi
AU - Ofek, Eran O.
AU - Bond, Ian A.
AU - Beichman, Charles
AU - Bryden, Geoff
AU - Carey, Sean
AU - Henderson, Calen
AU - Zhu, Wei
AU - Fausnaugh, Michael M.
AU - Wibking, Benjamin
AU - Udalski, Andrzej
AU - Poleski, Radek
AU - Mróz, Przemek
AU - Szymański, Michał K.
AU - Soszyński, Igor
AU - Pietrukowicz, Paweł
AU - Kozłowski, Szymon
N1 - Publisher Copyright: © 2024. The Author(s).
PY - 2024/11/1
Y1 - 2024/11/1
N2 - In the pursuit of understanding the population of stellar remnants within the Milky Way, we analyze the sample of ∼950 microlensing events observed by the Spitzer Space Telescope between 2014 and 2019. In this study we focus on a subsample of nine microlensing events, selected based on their long timescales, small microlensing parallaxes, and joint observations by the Gaia mission, to increase the probability that the chosen lenses are massive and the mass is measurable. Among the selected events we identify lensing black holes and neutron star candidates, with potential confirmation through forthcoming release of the Gaia time-series astrometry in 2026. Utilizing Bayesian analysis and Galactic models, along with the Gaia Data Release 3 proper-motion data, four good candidates for dark remnants were identified: OGLE-2016-BLG-0293, OGLE-2018-BLG-0483, OGLE-2018-BLG-0662, and OGLE-2015-BLG-0149, with lens masses of 3.0-1.3+1.8M☉, 4.7-2.1+3.2 M☉, 3.15-0.64+0..66 M☉ and 1.40-0.55+0.75 M☉, respectively. Notably, the first two candidates are expected to exhibit astrometric microlensing signals detectable by Gaia, offering the prospect of validating the lens masses. The methodologies developed in this work will be applied to the full Spitzer microlensing sample, populating and analyzing the timescale (tE) versus parallax (πE) diagram to derive constraints on the population of lenses in general and massive remnants in particular.
AB - In the pursuit of understanding the population of stellar remnants within the Milky Way, we analyze the sample of ∼950 microlensing events observed by the Spitzer Space Telescope between 2014 and 2019. In this study we focus on a subsample of nine microlensing events, selected based on their long timescales, small microlensing parallaxes, and joint observations by the Gaia mission, to increase the probability that the chosen lenses are massive and the mass is measurable. Among the selected events we identify lensing black holes and neutron star candidates, with potential confirmation through forthcoming release of the Gaia time-series astrometry in 2026. Utilizing Bayesian analysis and Galactic models, along with the Gaia Data Release 3 proper-motion data, four good candidates for dark remnants were identified: OGLE-2016-BLG-0293, OGLE-2018-BLG-0483, OGLE-2018-BLG-0662, and OGLE-2015-BLG-0149, with lens masses of 3.0-1.3+1.8M☉, 4.7-2.1+3.2 M☉, 3.15-0.64+0..66 M☉ and 1.40-0.55+0.75 M☉, respectively. Notably, the first two candidates are expected to exhibit astrometric microlensing signals detectable by Gaia, offering the prospect of validating the lens masses. The methodologies developed in this work will be applied to the full Spitzer microlensing sample, populating and analyzing the timescale (tE) versus parallax (πE) diagram to derive constraints on the population of lenses in general and massive remnants in particular.
UR - http://www.scopus.com/inward/record.url?scp=85209409244&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ad7bb1
DO - 10.3847/1538-4357/ad7bb1
M3 - مقالة
SN - 0004-637X
VL - 975
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 216
ER -