MICROLENSING BLACK HOLES IN OGLE AND GAIA (pron: Woocash Vizhikovski) Warsaw University Astronomical Observatory Microlensing Workshop, IAP Paris, January 2016
COLLABORATORS Zuzanna Kostrzewa-Rutkowska Krzysztof Rybicki Jan Skowron Przemek Mróz OGLE group in Warsaw Gaia Alerts group in Cambridge
STELLAR REMNANTS Neutron Stars
STELLAR REMNANTS Neutron Stars Kiziltan+2013
STELLAR REMNANTS Black Holes
STELLAR REMNANTS Black Holes Ozel+2010
GAP OR NOT GAP? GAP? Observations: Ozel+2010 Theory: Fryer&Kalogera 2001 Fryer et al. 2012
MICROLENSING About 20% of microlensing events should be due to stellar remnants (Gould 2000) 17% WD 3% NS 0.8% BH 2000 events found every year -> ~16 black holes every year!! so, where are they? Microlensing event rate for different lens populations (Gould 2000) -
CANDIDATES M_BH ~ 7 MSun Bennett+2001 X-ray follow-up: no signal from ISM accretion (Maeda et al. 2005; Nucita et al. 2006)
CANDIDATES astrometry OGLE-1999-BUL-32 Mao+2002 still the largest timescale microlensing event (te=640d)
CANDIDATES binary lens OGLE-1999-BUL-32 Shvartzvald+2015 with remnant component astrometry
SEARCH FOR LENSING REMNANTS OGLE-III: 2001-2009 150 millions of stars in the Bulge 3500 standard events for Bulge structural studies 59 high quality parallax events 19 events with P>50% having a remnant (dark) lens 15 events with P>75% having a remnant (dark) lens 3 BH lens candidates (P>95% remnant) Wyrzykowski+2015a, ApJS, 216,12 Wyrzykowski+2015b arxiv:1509.04899
GUESSING THE MASS Assume: - source is in the Bulge (selected sources from RC region) - lens is in the Disk - stellar remnants in the Galactic Disk move as all the stars E µrel te M= = E E
GUESSING THE MASS Assume: - source is in the Bulge (selected sources from RC region) - lens is in the Disk - stellar remnants in the Galactic Disk move as all the stars Calamida+2014 E µrel te M= = E E
BH CANDIDATES second longest lasting microlensing event ever! ~6 years of lensing! EWS: OGLE-2006-BLG-095 OGLE3-ULENS- te [d] Mass [M ] Distance [kpc] PAR-02 (Odra) solution + 296 6.9+4.0-3.0 1.9+1.2-0.6 solution - 256 8.3+4.6-3.2 2.4+1.3-0.7
BH CANDIDATES EWS: OGLE-2002-BLG-061 OGLE3-ULENS- te [d] Mass [M ] Distance [kpc] PAR-13 (Obra) solution + 172 5.3+2.7-2.1 2.9+1.4-1.0 solution - 171 4.9+2.81.9 2.4+1.4-0.9
BH IN THE MASS GAP? EWS: OGLE-2004-BLG-361 OGLE3-ULENS- te [d] Mass [M ] Distance [kpc] PAR-05 (Narew) solution + 174 3.3+1.9-1.3 2.6+1.3-0.8 solution - 176 4.0+2.1-1.7 2.0+1.1-0.6
NEARBY WHITE DWARF OR NEUTRON STAR? multiple-peak parallax event (second after OGLE-1999-BUL-19,Smith+2002) length: ~8 years the longest lasting microlensing event ever! not in EWS OGLE3-ULENSPAR-01 (Vistula) te [d] Mass [M ] Distance [kpc] 325 1.5+1.5-0.9 0.6+0.5-0.2
DETECTION EFFICIENCY
REMNANTS MASS DISTRIBUTION mass distribution for 15 dark lens candidates - no mass gap between NS and BH? binary systems GAP? single Wyrzykowski+2015b arxiv:1509.04899
GAIA SPACE MISSION GAIA is a scanning mission operating between 2014 and 2019(+1?) w no pointing, no change in the schedule, uniform coverage of the sky Simultaneous astrometry, photometry and spectroscopy Astrometry (V < 20) - MAIN TARGET: w completeness to 20 mag: 109 stars w parallax accuracy: 7 μas at <10 mag; 12 25 μas at 15 mag 100 300 μas at 20 mag Photometry (V < 20): w low-dispersion spectro-photometry w 8 20 mmag at 15 mag Radial velocity (V < 16.5 17): w Third component of space motion, perspective acceleration
1700deg2 Disk Fields Bulge and Sgr dsph Fields Number of Gaia observations after 5 years Supernovae Search Fields LMC and SEP Gaia figure by Nadia Blagorodnova, OGLE fields by Jan Skowron OGLE-GAIA SKY
CONFIRMING BHS WITH X-RAYS AND AO X-ray observations are the only way to confirm a BH candidate via its (weak) interaction with the interstellar medium (Bondi-Hoyle accretion) XMM + VLT/NACO proposal approved for 2016/2017 for 3 candidates! Expected X-ray flux for 8MO BH at 2kpc calculations by Peter Jonker VLT/NACO AO will help rule out Main Sequence lens. Zuzanna Kostrzewa-Rutkowska
SUMMARY we found at least 3 strong BH candidates among 59 parallax events found among 150 million stars monitored by OGLE-III 2001-2009 total of 15 dark remnant lens candidates mass distribution does not support NS-BH mass gap astrometry from Gaia necessary to compute masses accurately (see talk by Kris Rybicki) XMM+NACO follow-up in 2016/2017 will search for strong parallax microlensing events in OGLE-IV due to remnants, including binaries black hole lenses in OGLE-II,-III, -IV data (1996-2016)??
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