a study of dnos and qpos in cataclysmic variable stars

A study of DNOs and QPOs in Cataclysmic Variable starsHannes Breytenbach♋, Brian Warner, Patrick Woudt

University of Cape Town

♋ author email: [email protected]

SKA Postgraduate Bursary Conference 2011





CVs?





CVs? • Binary





CVs? • Binary• WD primary + MS secondary






Overfilling Roche Lobe







Mass Transfer







Mass Transfer

• Accretion disc







Mass Transfer

• Accretion disc Variability







Mass Transfer

• Accretion disc

DNOs?

Variability







Mass Transfer

• Accretion disc

Dwarf Nova OscillationsDNOs?

Variability







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until .







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until . .







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until . . .







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until . . . gas phase change







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until . . . gas phase change T, μ







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until . . . gas phase change μ







Mass Transfer

• Accretion disc


Variability

• Ṁ2 < Ṁ1 ρ until . . . gas phase change μ

“Cataclysmic”







Mass Transfer

• Accretion disc


Variability







Mass Transfer

• Accretion disc


Variability

• Seen in optical through X-ray







Mass Transfer

• Accretion disc


Variability

• Seen in optical through X-ray• PDNO ∼ 5 - 40 s







Mass Transfer

• Accretion disc


Variability

• Seen in optical through X-ray• PDNO ∼ 5 - 40 s• 103 |Ṗ≲ DNO|-1 10≲ 7







Mass Transfer

• Accretion disc


Variability

QPOs?







Mass Transfer

• Accretion disc


Variability

QPOs? Quasi-Periodic Oscillations







Mass Transfer

• Accretion disc


Variability


• Seen in optical through X-ray







Mass Transfer

• Accretion disc


Variability


• Seen in optical through X-ray• PDNO ∼ 30 - 600 s







Mass Transfer

• Accretion disc


Variability


• Seen in optical through X-ray• PDNO ∼ 30 - 600 s• 5 |Ṗ≲ DNO|-1 20 ≲







Mass Transfer

• Accretion disc


Variability


FT







Mass Transfer

• Accretion disc


Variability








Mass Transfer

• Accretion disc

DNOs?

Variability

QPOs?







Mass Transfer

• Accretion disc

DNOs?

Variability

QPOs?

?







Mass Transfer

• Accretion disc

DNOs?

Variability

QPOs?

?

“Judge a man by his questions rather than by his answers.” - Pierre-Marc-Gaston, duc de Lévis (1764-1830) Maximes et réflexions sur différents sujets de morale et de politique (Paris, 1808)







Mass Transfer

• Accretion disc

DNOs?

Variability

QPOs?

?Thank you!

“Judge a man by his questions rather than by his answers.” - Pierre-Marc-Gaston, duc de Lévis (1764-1830) Maximes et réflexions sur différents sujets de morale et de politique (Paris, 1808)

a study of dnos and qpos in cataclysmic variable stars

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