TY - JOUR
T1 - An Isolated Stellar-mass Black Hole Detected through Astrometric Microlensing*
AU - PLANET Collaboration
AU - MiNDSTEp Collaboration
AU - the OGLE Collaboration
AU - The RoboNet Collaboration
AU - Sahu, Kailash C.
AU - Anderson, Jay
AU - Casertano, Stefano
AU - Bond, Howard E.
AU - Udalski, Andrzej
AU - Dominik, Martin
AU - Calamida, Annalisa
AU - Bellini, Andrea
AU - Brown, Thomas M.
AU - Rejkuba, Marina
AU - Bajaj, Varun
AU - Kains, Noe
AU - Ferguson, Henry C.
AU - Fryer, Chris L.
AU - Yock, Philip
AU - Mroz, Przemek
AU - Kozlowski, Szymon
AU - Pietrukowicz, Pawel
AU - Poleski, Radek
AU - Skowron, Jan
AU - Soszynski, Igor
AU - Szymanski, Michal K.
AU - Ulaczyk, Krzysztof
AU - Wyrzykowski, Lukasz
AU - Barry, Richard K.
AU - Bennett, David P.
AU - Bond, Ian A.
AU - Hirao, Yuki
AU - Silva, Stela Ishitani
AU - Kondo, Iona
AU - Koshimoto, Naoki
AU - Ranc, Clement
AU - Rattenbury, Nicholas J.
AU - Sumi, Takahiro
AU - Suzuki, Daisuke
AU - Tristram, Paul J.
AU - Vandorou, Aikaterini
AU - Beaulieu, Philippe
AU - Marquette, Jean-Baptiste
AU - Cole, Andrew
AU - Fouque, Pascal
AU - Hill, Kym
AU - Dieters, Stefan
AU - Coutures, Christian
AU - Dominis-Prester, Dijana
AU - Bennett, Clara
AU - Bachelet, Etienne
AU - Menzies, John
AU - Albrow, Michael
AU - Pollard, Karen
AU - Gould, Andrew
AU - Yee, Jennifer C.
AU - Allen, William
AU - Almeida, Leonardo A.
AU - Christie, Grant
AU - Drummond, John
AU - Gal-Yam, Avishay
AU - Gorbikov, Evgeny
AU - Jablonski, Francisco
AU - Lee, Chung-Uk
AU - Maoz, Dan
AU - Manulis, Ilan
AU - McCormick, Jennie
AU - Natusch, Tim
AU - Pogge, Richard W.
AU - Shvartzvald, Yossi
AU - Jorgensen, Uffe G.
AU - Alsubai, Khalid A.
AU - Andersen, Michael, I
AU - Bozza, Valerio
AU - Novati, Sebastiano Calchi
AU - Burgdorf, Martin
AU - Hinse, Tobias C.
AU - Hundertmark, Markus
AU - Husser, Tim-Oliver
AU - Kerins, Eamonn
AU - Longa-Pena, Penelope
AU - Mancini, Luigi
AU - Penny, Matthew
AU - Rahvar, Sohrab
AU - Ricci, Davide
AU - Sajadian, Sedighe
AU - Skottfelt, Jesper
AU - Snodgrass, Colin
AU - Southworth, John
AU - Tregloan-Reed, Jeremy
AU - Wambsganss, Joachim
AU - Wertz, Olivier
AU - Tsapras, Yiannis
AU - Street, Rachel A.
AU - Bramich, D. M.
AU - Horne, Keith
AU - Steele, Iain A.
N1 - Funding Information:
U.G.J. acknowledges funding from the European Union H2020-MSCA-ITN-2019 under grant No. 860470 (CHAMELEON) and from the Novo Nordisk Foundation Interdisciplinary Synergy Programme grant no. NNF19OC0057374.
Funding Information:
T.C.H. acknowledges financial support from the National Research Foundation (NRF; No. 2019R1I1A1A 01059609).
Funding Information:
L.M. acknowledges support from the ``Fondi di Ricerca Scientificad’Ateneo 2021’’ of the University of Rome ``Tor Vergata.’’
Funding Information:
Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at STScI, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. Support for this research was provided by NASA through grants from STScI. HST data used in this paper are available from the Mikulski Archive for Space Telescopes at STScI, 82
Funding Information:
The MOA project is supported by JSPS KAK-ENHI grant Nos. JSPS24253004, JSPS26247023, JSPS23340064, JSPS15H00781, JP16H06287, 17H02871, and 19KK0082.
Funding Information:
Ł.W. acknowledges support from the Polish NCN grant Daina No. 2017/27/L/ST9/03221.
Funding Information:
D.D.P. acknowledges support by the University of Rijeka through the grant uniri-prirod-18-48.
Funding Information:
J.-P.B. acknowledges support by the University of Tasmania through the UTAS Foundation and the endowed Warren Chair in Astronomy, and support by ANR COLD-WORLDS (ANR-18-CE31-0002) at Le Centre National de la Recherche Scientifique (CNRS) in Paris and the Laboratoire d’astrophysique de Bordeaux.
Funding Information:
This research is based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/7/6
Y1 - 2022/7/6
N2 - We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry of the source star of the long-duration (tE ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as MOA-11-191/OGLE-11-462), in the direction of the Galactic bulge. HST imaging, conducted at eight epochs over an interval of 6 yr, reveals a clear relativistic astrometric deflection of the background star's apparent position. Ground-based photometry of MOA-11-191/OGLE-11-462 shows a parallactic signature of the effect of Earth's motion on the microlensing light curve. Combining the HST astrometry with the ground-based light curve and the derived parallax, we obtain a lens mass of 7.1 ± 1.3 M⊙ and a distance of 1.58 ± 0.18 kpc. We show that the lens emits no detectable light, which, along with having a mass higher than is possible for a white dwarf or neutron star, confirms its BH nature. Our analysis also provides an absolute proper motion for the BH. The proper motion is offset from the mean motion of Galactic disk stars at similar distances by an amount corresponding to a transverse space velocity of ∼45 km s−1, suggesting that the BH received a "natal kick" from its supernova explosion. Previous mass determinations for stellar-mass BHs have come from radial velocity measurements of Galactic X-ray binaries and from gravitational radiation emitted by merging BHs in binary systems in external galaxies. Our mass measurement is the first for an isolated stellar-mass BH using any technique.
AB - We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry of the source star of the long-duration (tE ≃ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462 (hereafter designated as MOA-11-191/OGLE-11-462), in the direction of the Galactic bulge. HST imaging, conducted at eight epochs over an interval of 6 yr, reveals a clear relativistic astrometric deflection of the background star's apparent position. Ground-based photometry of MOA-11-191/OGLE-11-462 shows a parallactic signature of the effect of Earth's motion on the microlensing light curve. Combining the HST astrometry with the ground-based light curve and the derived parallax, we obtain a lens mass of 7.1 ± 1.3 M⊙ and a distance of 1.58 ± 0.18 kpc. We show that the lens emits no detectable light, which, along with having a mass higher than is possible for a white dwarf or neutron star, confirms its BH nature. Our analysis also provides an absolute proper motion for the BH. The proper motion is offset from the mean motion of Galactic disk stars at similar distances by an amount corresponding to a transverse space velocity of ∼45 km s−1, suggesting that the BH received a "natal kick" from its supernova explosion. Previous mass determinations for stellar-mass BHs have come from radial velocity measurements of Galactic X-ray binaries and from gravitational radiation emitted by merging BHs in binary systems in external galaxies. Our mass measurement is the first for an isolated stellar-mass BH using any technique.
U2 - 10.3847/1538-4357/ac739e
DO - 10.3847/1538-4357/ac739e
M3 - Article
SN - 0004-637X
VL - 933
SP - 1
EP - 28
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 83
ER -