Refining Microlensing Models with KECK Adaptive Optics. Virginie Batista

Transcription

1 Refining Microlensing Models with KECK Adaptive Optics Virginie Batista Institut d Astrophysique de Paris Centre National d Etudes Spatiales Collaborators : J.-P. Beaulieu, D. Bennett, A. Bhattacharya, A. Fukui, A. Gould, J.-B. Marquette 20th Annual Conference on Gravitational Microlensing - Paris 2016

2 Refining microlensing models with AO Measuring the flux from the lens (or upper limits) => mass-luminosity function (isochrones) Measuring the heliocentric lens-source relative proper motion on 5-10 years old microlensing events => µgeocentric: a microlensing parameter Measuring the lens/source flux ratio => lens flux independent from the Keck photometry calibration with 2MASS Objective: mass and distance distributions from microlensing for the period

3 KECK, HST, SUBARU, KECK, HST, VLT VLT KECK (Hawaï, NASA) : 2012, 2013 & 2015 SUBARU (Hawaï, Japan) : 2013 HST : 2011 NACO VLT (ESO) : observed microlensing planetary systems MOA-2011-BLG-293Lb : Batista et al. (2014) MOA-2011-BLG-262Lb : Bennett et al. (2014) OGLE-2005-BLG-169Lb : Batista et al. (2015), Bennett et al. (2015) OGLE-2012-BLG-0563Lb : Fukui et al. (2015) OGLE-2012-BLG-0026Lb,c : Beaulieu et al. (2016) MOA-2010-BLG-477Lb : Batista et al. in prep. 3

4 OGLE-2005-BLG-169Lb - Keck observations 2013 Gould et al A Neptune around a main sequence star Batista et al Bennett et al First source-lens relative proper motion measurement for a planetary event, 8 years after the event 4

5 Distance and mass - Bayesian analysis from KECK Heliocentric relative proper motion µrel, helio Source distance DS (Nataf et al. (2013)) Geocentric relative proper motion µrel, geo Lens/source flux ratio fl/fs Mass-luminosity function Isochrones (Girardi, An) Lens distance D L Lens mass M from light curve Source flux fs Timescale te t E,in, D S,in, µ rel, helio,in => θ E,out, µ rel, geo,out, D L,out MCMC Einstein radius θ E 5

6 Comparison HST & KECK HST Keck Bennett et al Batista et al μ rel_l = 7.39 ±.20 mas/yr μ rel_l = 7.28 ±.12 mas/yr μ rel_b = 1.33 ±.23 mas/yr μ rel_b = 1.54 ±.12 mas/yr Host mass: 0.69 ±.02 M Planet Mass: 14.1 ± 0.9 M D L = 4.1 ± 0.4 kpc Projected Separation(a ): 3.5 ± 0.3 AU Comparison with Gould et al. (2006) : Host mass: 0.65 ±.05 M Planet Mass: 13.2 ± 1.5 M D L = 4.0 ± 0.4 kpc Projected Separation(a ): 3.4 ± 0.3 AU Host mass: 0.5 ± 0.3 M D L = 2.7 ± 1.6 kpc 6

7 OGLE-2012-BLG-0026Lb,c Han et al Beaulieu et al cold giant planets orbiting a G star Observations KECK + SUBARU 7

8 OGLE-2012-BLG-0026Lb,c: revisiting the modeling Additional data: CTIO H band data 0.61m B&C telescope in NZ (I band) Source distance DS range : 8.28 ± 1.44 kpc Surface brightness relation from Boyajian et al. (2013, 2014) 8

9 OGLE-2012-BLG-0026Lb,c: revisiting the modeling Bretelli et al isochrones HL = ± 0.08 => New model consistent with a G main-sequence disk star of solar metallicity and an age of ~4-6 Gyr. => Two cold giant planets of ± 0.08 MJup and 0.86 ± 0.07 MJup, at projected distances 4.0 ± 0.5 AU and 4.8 ± 0.7 AU. 9

10 MOA-2010-BLG-477Lb Bachelet et al KECK images in July 2015 Wide camera 0.04 arcsec/pixel VVV survey Galactic model + Parallax constraint (one component) (orbital motion / parallax degeneracy) Narrow camera 0.01 arcsec/pixel 0.13 M_sun < M_L < 1.0 M_sun 0.5 kpc < D_L < 2.8 kpc 10

11 MOA-2010-BLG-477Lb Bachelet et al Source position KECK image Lens? OGLE-III reference image Difference Imaging Analysis with CTIO data Source Blended light in µlens light curve 11

12 MOA-2010-BLG-477Lb If this is the lens H = 17.6 µrel,helio > 20 mas/yr 2 x the prediction! => lens would be in the very foreground, not compatible with its flux and microlensing model Excess of flux at the source position HS = 17.35, Hexcess = 17.9 Source profile slightly elongated Lens-source separation ~ 50 mas (E~30mas, N~40mas) => consistent with the microlensing model, DL ~ 2 kpc 12

13 MOA-2010-BLG-477Lb: centroid shift / further work Detecting the lens: measuring the centroid shift with DIA using the CTIO data, fitting the PSF of the 2 stars as it was done for 169 in the HST paper, observing the target with NACO in 2016 when the lens is further away from the source. Lens Source 13

14 VLT (NACO) observations in 2016 VLT time allocation: 9 hours List of targets: MOA-2010-BLG-477 OGLE-2003-BLG-235 OGLE-2005-BLG-71 MOA-2010-BLG-328 OGLE-2015-BLG-1395 OGLE-2015-BLG-1726 And > 10 other Keck observations to analyse 14

15 Conclusion and further applications Resolves degeneracies in microlensing models Such measurements will help us to build statistics on planet mass function depending on host star mass and distance Similar mass measurement method will be used in the context of future space missions EUCLID and WFIRST 15