Spitzer Microlensing parallax reveals two isolated stars in the Galactic bulge
Creators: name: Zang, Weicheng
name: Shvartzvald, Yossi
name: Wang, Tianshu
name: Udalski, Andrzej
name: Lee, Chung-Uk
name: Sumi, Takahiro
name: Skottfelt, Jesper
name: Li, Shun-Sheng
name: Mao, Shude
name: Zhu, Wei
name: Yee, Jennifer C.
name: Novati, Sebastiano Calchi
name: Beichman, Charles A.
name: Bryden, Geoffery
name: Carey, Sean
name: Gaudi, B. Scott
name: Henderson, Calen B.
name: Mróz, Przemek
name: Skowron, Jan
name: Poleski, Radoslaw
name: Szymański, Michał K.
name: Soszyński, Igor
name: Pietrukowicz, Paweł
name: Kozłowski, Szymon
name: Ulaczyk, Krzysztof
name: Rybicki, Krzysztof A.
name: Iwanek, Patryk
name: Bachelet, Etienne
name: Christie, Grant
name: Green, Jonathan
name: Hennerley, Steve
name: Maoz, Dan
name: Natusch, Tim
name: Pogge, Richard W.
name: Street, Rachel A.
name: Tsapras, Yiannis
name: Albrow, Michael D.
name: Chung, Sun-Ju
name: Gould, Andrew
name: Han, Cheongho
name: Hwang, Kyu-Ha
name: Jung, Youn Kil
name: Ryu, Yoon-Hyun
name: Shin, In-Gu
name: Cha, Sang-Mok
name: Kim, Dong-Jin
name: Kim, Hyoun-Woo
name: Kim, Seung-Lee
name: Lee, Dong-Joo
name: Lee, Yongseok
name: Park, Byeong-Gon
name: Pogge, Richard W.
name: Bond, Ian A.
name: be, Fumio
name: Barry, Richard
name: Bennett, David P.
name: Bhattacharya, Aparna
name: Donachie, Martin
name: Fukui, Akihiko
name: Hirao, Yuki
name: Itow, Yoshitaka
name: Kondo, Iona
name: Koshimoto, Naoki
name: Li, Man Cheung Alex
name: Matsubara, Yutaka
name: Muraki, Yasushi
name: Miyazaki, Shota
name: Nagakane, Masayuki
name: Ranc, Clément
name: Rattenbury, Nicholas J.
name: Suematsu, Haruno
name: Sullivan, Denis J.
name: Suzuki, Daisuke
name: Tristram, Paul J.
name: Yonehara, Atsunori
name: Dominik, Martin
name: Hundertmark, Markus
name: Jørgensen, Uffe G.
name: Rahvar, Sohrab
name: Sajadian, Sedighe
name: Snodgrass, Colin
name: Bozza, Valerio
name: Burgdorf, Martin J.
name: Evans, Daniel F.
name: Jaimes, Roberto Figuera
name: Fujii, Yuri I.
name: Mancini, Luigi
name: Longa-Peña, Penelope
name: Helling, hristiane
name: Peixinho, Nuno
name: Rabus, Markus
name: Southworth, John
name: Unda-Sanzana, Eduardo
name: von Essen, Carolina
Publisher: name: arXiv
Year: 2019
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the mass and distance measurements of two single-lens events from the 2017 Spitzer microlensing campaign. The ground-based observations yield the detection of finite-source effects, and the microlens parallaxes are derived from the joint analysis of ground-based observations and Spitzer observations. We find that the lens of OGLE-2017-BLG-1254 is a $0.60 \pm 0.03 M_{\odot}$ star with $D_{\rm LS} = 0.53 \pm 0.11~\text{kpc}$, where $D_{\rm LS}$ is the distance between the lens and the source. The second event, OGLE-2017-BLG-1161, is subject to the known satellite parallax degeneracy, and thus is either a $0.51^{+0.12}_{-0.10} M_{\odot}$ star with $D_{\rm LS} = 0.40 \pm 0.12~\text{kpc}$ or a $0.38^{+0.13}_{-0.12} M_{\odot}$ star with $D_{\rm LS} = 0.53 \pm 0.19~\text{kpc}$. Both of the lenses are therefore isolated stars in the Galactic bulge. By comparing the mass and distance distributions of the eight published Spitzer finite-source events with the expectations from a Galactic model, we find that the Spitzer sample is in agreement with the probability of finite-source effects occurrence in single lens events.
description: 16 pages, 6 Figures. Submitted to AAS journal