Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Age Calibration from Coeval White Dwarfs in K2 and TESS

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.

jjhermes

January 17, 2018
Tweet

More Decks by jjhermes

Other Decks in Science

Transcript

  1. http://jjherm.es
    J.J. Hermes
    Hubble Fellow, UNC Chapel Hill
    Age Calibration from Coeval
    White Dwarfs in K2 and TESS

    View Slide

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

    View Slide

  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

    View Slide

  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

    View Slide

  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)

    View Slide

  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

    View Slide

  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

    View Slide

  8. Age Calibration from Coeval
    White Dwarfs in K2 and TESS

    View Slide

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

    View Slide

  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

    View Slide

  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

    View Slide

  12. Age Calibration from Coeval
    White Dwarfs in K2 and TESS

    View Slide

  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

    View Slide

  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

    View Slide

  15. Oh et al. 2017
    Andrews, Chanamé & Agüeros 2017
    Gaia will
    revolutionize
    finding common
    proper-motion
    binaries

    View Slide

  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)

    View Slide

  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

    View Slide

  18. Clusters are a party

    View Slide

  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

    View Slide

  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]

    View Slide