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Testing Substellar Models with Keck LGS AO Dynamical Masses. Trent Dupuy IfA/Hawaii Michael Liu IfA/Hawaii Michael Ireland U. Sydney. binaries!. K-band 0.7” FOV. Liu et al., Allers et al., Biller et al., in prep. Directly imaged planets. Initial Mass Function.
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Testing Substellar Models with Keck LGS AO Dynamical Masses Trent DupuyIfA/Hawaii Michael Liu IfA/Hawaii Michael Ireland U. Sydney
binaries! Trent Dupuy (IfA/Hawaii) K-band 0.7” FOV Liu et al., Allers et al., Biller et al., in prep.
Trent Dupuy (IfA/Hawaii) Directly imaged planets Initial Mass Function It is very important to test substellar theoretical models. Brown Dwarf Teff scale Young cluster ages
Trent Dupuy (IfA/Hawaii) Directly imaged planets Initial Mass Function Brown Dwarf Teff scale Young cluster ages
Trent Dupuy (IfA/Hawaii) Directly imaged planets Initial Mass Function Young cluster ages IC 2391 Pleiades Persei Brown Dwarf Teff scale
Trent Dupuy (IfA/Hawaii) Directly imaged planets Initial Mass Function Brown Dwarf Teff scale Young cluster ages Chabrier (2003)
Trent Dupuy (IfA/Hawaii) Initial Mass Function Directly imaged planets HR 8799 Brown Dwarf Teff scale Young cluster ages Marois et al. (2008)
To test substellar models we are measuring dynamical masses. Trent Dupuy (IfA/Hawaii) Directly imaged planets Initial Mass Function Brown Dwarf Teff scale Young cluster ages
0.095” 0.095” Dupuy et al. (2009) Trent Dupuy (IfA/Hawaii) Why is AO Needed? orbit size ~ 1–3 AU distance ~ 20 pc 50150 mas LGS AOvs. HST 34 higher resolution in the NIR 15 objects/night (cf. 1 per HST orbit)
published 0.2” Trent Dupuy (IfA/Hawaii) Keck LGS AO program targets ~30 binaries over ~3 years. 400 2MASS J1728+39AB (L7+T) a subset of 106 possible orbits HST/WFPC2 2000 200 B Dec (mas) 0 Keck LGS 2007 A 200 400 400 200 0 -200 -400 RA (mas) Novel technique using data from two epochs culls long-period orbits from sample. Carefully selected binaries likely to complete enough of their orbit by 2010.
3d3 = P2 Trent Dupuy (IfA/Hawaii) Infrared Parallaxes with CFHT a3 CFHT (3.6-m @Mauna Kea) Mtot = • queue service mode • excellent seeing on Mauna Kea • ultracool objects brightest in the near-infrared • DCR effects smaller at longer wavelengths P2
Trent Dupuy (IfA/Hawaii) Objects with dynamical masses FGK stars Previous dynamical masses (N=4) 2MASS J0746+2000, Gl 569Bab, LHS 1070BC, 2MASS J0535-0546 Leinert et al. (2001), Bouy et al. (2004), Zapatero Osorio et al. (2004), Stassun et al. (2006), Simon et al. (2006), Seifahrt et al. (2008) M stars Lbol (L) late-M L Our dynamical masses (N=4) Gl 802B, 2MASS J1534-2952, HD 130948BC, LHS 2397a Ireland et al. (2008); Liu, Dupuy, & Ireland (2008); Dupuy, Liu, & Ireland (2009a,b) T Teff (K)
Trent Dupuy (IfA/Hawaii) Liu et al. (2008) Dupuy et al. (2009a) Dupuy et al. (2009b) 2 = 0.9 2 = 1.0 2 = 1.1 Mtot = 59 ± 3 MJup Mtot = 114 ± 3 MJup Mtot = 153 ± 15 MJup • Orbit fit using Markov Chain Monte Carlo • Astrometric errors derived from Monte Carlo simulations of artificial binaries
masking masking Trent Dupuy (IfA/Hawaii) Dupuy et al. (2009b) • Orbit fit using Markov Chain Monte Carlo • Astrometric errors derived from Monte Carlo simulations of artificial binaries
Trent Dupuy (IfA/Hawaii) Substellar model tests • Do models predict the luminosity evolution of substellar objects accurately? • Do evolutionary and atmospheric models give consistent temperature estimates? • Do evolutionary models accurately predict near-infrared colors of ultracool dwarfs?
Mtot = 0.1090.003 M Keck HST HST Keck Age Indicator Age (Gyr) Precision Gyrochronology 0.8±0.2 25% Chrom. activity 0.5±0.3 60% Isochrones 0.3–2.5 ~2 X-ray activity ~Hyades ... Lithium ~Hyades ... References — Mamajek & Hillenbrand (2008); Barnes (2007); Takeda et al. (2007); Stern et al. (1995); Gaidos (1998); Gaidos (2000); Hünsch et al. (1999); Stelzer & Neuhäuser (2001); Soderblom et al. (1993a,b,c) Trent Dupuy (IfA/Hawaii) HD 130948BC Dupuy et al. (2009) Mass, age, and Lbol fully constrain evolutionary models for the first time
Trent Dupuy (IfA/Hawaii) 1. Do models predict the luminosity evolution of substellar objects accurately? B component C component 10-3 Lbol (L) 10-4 NO: Models are ~23 under-luminous! Lyon Tucson 10-5 0.1 1 0.1 1 Age (Gyr) Age (Gyr)
Measure Lboldirectly Evol. modeltracks for themeasured mass Teff from fittingmodel atms toT dwarf SEDs Trent Dupuy (IfA/Hawaii) 2. Do evolutionary and atmospheric models give consistent temperature estimates? 10-4 NO: atm. models ~100 K warmer than evol. models Lbol (L) 10-5 2MASS J1534-2952AB T5.5 T5 10-6 1400 1200 1000 800 Teff (K) Liu, Dupuy & Ireland (2008) Liu, Dupuy & Ireland (2008)
Dupuy et al. (2009) Liu et al. (2008) Dupuy et al. (2009) Dupuy et al. (2009, subm.) HD 130948BC 2MASS J1534-2952AB LHS 2397aAB L4+L4 L7 M8 T5.5 M8 T5 M8 Dupuy, Liu & Ireland (2008) Liu, Dupuy & Ireland (2008) Dupuy, Liu & Ireland (2009) Dupuy & Liu (2009) Trent Dupuy (IfA/Hawaii) 3. Do evolutionary models accurately predict near-infrared colors of ultracool dwarfs? NO: Over a broad range of spectral types, models harbor varying systematic errors.
Trent Dupuy (IfA/Hawaii) Substellar model tests • Do models predict the luminosity evolution of substellar objects accurately? • No: ~23 under-luminous • Do evolutionary and atmospheric models give consistent temperature estimates? • No: typically off by 100 K • Do evolutionary models accurately predict near-infrared colors of ultracool dwarfs? • No: for JHK colors at all spectral types
Trent Dupuy (IfA/Hawaii) Future model tests Liu et al. (2006) • Does the L/T transition (dust removal) depend on surface gravity? • dust physics in stars/BDs/planets • Do models predict thelithium depletion of substellar objects accurately? • young cluster ages (e.g., Pleiades) • Do orbital parameters (e.g., eccentricity) match brown dwarf formation models?
Trent Dupuy (IfA/Hawaii) Future model tests • Does the L/T transition (dust removal) depend on surface gravity? • dust physics in stars/BDs/planets • Do models predict thelithium depletion of substellar objects accurately? • young cluster ages (e.g., Pleiades) • Do orbital parameters (e.g., eccentricity) match brown dwarf formation models?
Trent Dupuy (IfA/Hawaii) Future model tests • Does the L/T transition (dust removal) depend on surface gravity? • dust physics in stars/BDs/planets • Do models predict thelithium depletion of substellar objects accurately? • young cluster ages (e.g., Pleiades) • Do orbital parameters (e.g., eccentricity) match brown dwarf formation models? Stamatellos et al. (2008)