Age Calibration from Coeval White Dwarfs in K2 and TESS

70d4f7eb14525537a3fd6c15a33a8ac1?s=47 jjhermes
January 17, 2018

Age Calibration from Coeval White Dwarfs in K2 and TESS

Conference presentation, 20 min. January 2018: Dwarf Stars and Clusters with K2, Boston, MA, USA.

70d4f7eb14525537a3fd6c15a33a8ac1?s=128

jjhermes

January 17, 2018
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  1. http://jjherm.es J.J. Hermes Hubble Fellow, UNC Chapel Hill Age Calibration

    from Coeval White Dwarfs in K2 and TESS
  2. Star Trek writer James Blish put planet Vulcan in orbit

    around 40 Eri A
  3. Star Trek writer James Blish put planet Vulcan in orbit

    around 40 Eri A The age of 40 Eri A is ~1.8 Gyr
  4. 40 Eri, S. Smith Star Trek writer James Blish put

    planet Vulcan in orbit around 40 Eri A 40 Eri B: coeval white dwarf with total age ~1.8 Gyr I have evolved telepathy in less than 2 billion years… ~35 au ~400 au Bond, Bergeron & Bédard 2017
  5. WD Teff /Mass à WD Cooling Age WD Initial-Final Mass

    Relation à Main-Sequence Mass/Age Total System Age(~30%) How Do We Get Coeval Ages from White Dwarfs? + = - Cooling ages come from WD evolution models - Calibrated by WDs in clusters with known turnoff ages WD Teff /log(g)
  6. see also Cummings et al. 2016 How do we build

    an Mi /Mf relation? E.g.: 0.77(0.03) M¤ WD in NGC 2527(630 Myr) 185 Myr WD cooling age tprog = 441 Myr -> Mprog = 3.1 M¤ Raddi et al. 2016
  7. Bond, Bergeron & Bédard 2017 0.573±0.018 M¤ 17,200±110 K WD

    Cooling Age: ~122 Myr + Cluster-Calibrated Initial-to-Final Mass Relation (Cummings et al. 2016): 1.8 M¤ Progenitor: ~1.7 Gyr MS age 40 Eri, S. Smith ~35 AU ~400 AU 40 Eri B Total Age ~1.8 Gyr
  8. Age Calibration from Coeval White Dwarfs in K2 and TESS

  9. Rebassa-Mansergas et al. sdss-wdms.org K2 Campaign 5

  10. WD 15,070(2000) K logg = 8.69(0.326) 1.04(0.173) M¤ ~0.8 Gyr

    total age M3 0.38(0.07) M¤ Prot = 4.59 d
  11. A handful of composite WD+dM in K2 with likely dM

    rotation periods - All M1−M3 - No radial-velocity variations in SDSS subspectra - Spatially unresolved (all >200 pc away) Jennifer van Saders 0.3 < M/M¤ < 0.4 −0.4 < [Z/H] < +0.4 Fast and slow initial rotation rates
  12. Age Calibration from Coeval White Dwarfs in K2 and TESS

  13. Talbot & Gänsicke 2018, in prep. G0 PMRA = -22.0(2.3)

    mas/yr PMDec = -16.0(2.4) mas/yr WD PMRA = -22.2(4.7) mas/yr PMDec = -24.7(4.7) mas/yr Distance: ~260 pc Projected Sep: >28000 au 16,280(180) K 0.61(0.02) M¤ 2.1 M¤ progenitor ~1.1 Gyr total age
  14. 5.0 7.5 10.0 12.5 15.0 Primary T (mag) 0 1

    2 3 4 5 6 7 8 9 N 12 14 16 18 20 WD secondary V (mag) 0 2 4 6 8 10 1 10 100 1000 Separation (arcsec) 0 2 4 6 8 10 12 N 1.0 10.0 Total Age (Gyr) 0 2 4 6 8 10 N JJH, Jennifer van Saders, Boris Gänsicke, Jeff Andrews, Alberto Rebassa-Mansergas, Steve Kawaler, Pier- Emmanuel Tremblay, Julio Chanamé, Marcel Agüeros, Jay Farihi, James Davenport, Chris Clemens TESS Coeval Degenerates Survey, Cycle 1 A-1 F-7 G-12 K-12 M-26
  15. Oh et al. 2017 Andrews, Chanamé & Agüeros 2017 Gaia

    will revolutionize finding common proper-motion binaries
  16. WD Teff /Mass à WD Cooling Age WD Initial-Final Mass

    Relation à Main-Sequence Mass/Age Total System Age How Do We Improve Coeval Ages from White Dwarfs? + = - Core C/O Ratio (where heat stored) - Envelope Masses (opacities, how fast heat escapes) - Improved MS Ages - More WDs in Clusters for IFMR - More Wide WD+WD Binaries WD Teff /log(g)
  17. WD Teff /Mass à WD Cooling Age WD Initial-Final Mass

    Relation à Main-Sequence Mass/Age Total System Age (~10%) How Do We Improve Coeval Ages from White Dwarfs? - Core C/O Ratio (where heat stored) - Envelope Masses (opacities, how fast heat escapes) - Improved MS Ages - More WDs in Clusters for IFMR - More Wide WD+WD Binaries WD Teff /log(g) White Dwarf Asteroseismology with K2/TESS Gaia
  18. Clusters are a party

  19. Coeval Degerates: Clusters of Two Calibrate gyrochronology, age-activity, & age-flaring

    continuously out to 8-10 Gyr in the solar neighborhood Gaia will uncover orders more wide WD+MS binaries
  20. A ‘typical’ white dwarf electron degenerate C/O core (r =

    8500 km) non-degenerate He layer (260 km) non-degenerate H layer (30 km) [thermal reservoir] [insulating blanket]