White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr....

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White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin Kilic, Carlos Allende Prieto, Alex Gianninas, JJ Hermes Credit: NASA / Dana Berry

Transcript of White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr....

Page 1: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

White Dwarf Binaries from an E-M perspective

Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics

Collaborators: Mukremin Kilic, Carlos Allende Prieto, Alex Gianninas, JJ Hermes Credit: NASA / Dana Berry

Page 2: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

R ≈ 1 Rsun τ ≈ 1010 yrs

R ≈ 100 Rsun

τ ≈ 108 yrs R ≈ 0.01 Rsun τ ≈ ∞ yrs

White dwarf Red giant Star

Background

Page 3: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

Binary Stars

Binary Star

Binary WD

Common Envelope

Page 4: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

Model Predictions

Nelemans et al 2001

Page 5: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

MMT Telescope

Page 6: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

Compact Object = High Surface Gravity

Main Sequence Star Teff = 12,000 K log g = 3.9 (cgs)

White Dwarf Teff = 12,000 K log g = 7.5 (cgs)

Page 7: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

The ELM Survey

Fukugita et al (1996)

Brown et al. (2011c)

Page 8: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

5.9 hr binary

Kilic, Brown et al 2010

Page 9: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

1.0 hr binary

Kilic, Brown et al 2010

Page 10: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

39 min binary

Kilic, Brown et al 2011a

Page 11: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

Dozens of Merging WD Binaries

Brown, Kilic et al 2013 Measured Inferred

Page 12: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

New: 20 min binary “WD 0931”

Kilic, Brown et al 2014a

Page 13: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

ELM WD Verification Binaries

Gianninas et al 2014

WD0931

Page 14: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

12.75 min binary “J0651”

Brown, Kilic et al 2011a

Page 15: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

Eclipsing, tidally distorted binary

Hermes, Brown, Kilic et al 2012a

Page 16: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

J0651 vs Hulse-Taylor pulsar

Weisberg et al. 2010, ApJ, 722, 1030

Hermes et al. 2012, ApJ, 757, L21

Page 17: White Dwarf Binaries - University of Florida · White Dwarf Binaries from an E-M perspective Dr. Warren R. Brown Smithsonian Institution Center for Astrophysics Collaborators: Mukremin

Coming Attractions

•  Discovery survey.

•  Identify verification binaries.

•  Gravitational wave detections.