Time Domain Astrophysics

Stephen PotterSouth African Astronomical Observatory

Overview

What is Time Domain Astrophysics (Astrotomography)? Variability in Interacting Binaries

Cataclysmic Variables Doppler Tomography

Roche Tomography

Stokes Imaging

Eclipse Mapping

SALT first Science High speed CCD photometry

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Variability in Interacting Binaries

– Accretion onto WD in CVs – Porb : minutes – hours– Pspin : tens of seconds – Mass accretion events/ outbursts : months– Magnetic cycles : years – decades

– WD/inner disc dominate soft X-ray, UV (SALT strength) – Outer disc emission mostly in optical– Mass donor reveals itself in the red/IR

– For X-ray binaries (NS/BH) keV/MeV emission + – variability as fast as milliseconds

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Cataclysmic Variables

A.P. Beardmore http://www.astro.keele.ac.uk/~apb/OGL_CV/ 4

Magnetic Cataclysmic Variables

A.P. Beardmore http://www.astro.keele.ac.uk/~apb/OGL_CV/ 5

Magnetic Cataclysmic Variables

A.P. Beardmore http://www.astro.keele.ac.uk/~apb/OGL_CV/ 6

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Doppler Tomography

Schwope et al, 1997, A&A, 319, 894 8

Doppler Tomography

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Roche Tomography

Potter, Romero-Colmenero, Watson, Buckley, Phillips 2004, MNRAS, 348, 31610

Spectral eclipse mapping

Rutten et al. 1993 Nature, 362, 518 11

Multi-epoch Doppler Tomography

Schwope et al. 2000, MNRAS, 313, 533 12

Spin Doppler Tomography

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Steeghs, D., Harlaftis, E.T., Horne, K., 1999, MNRAS, 306, 348

Targets of opportunityDoppler Tomography

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Spectral eclipse mapping

Baptista et al. 2000 MNRAS, 314, 727 15

Stokes imaging

Potter et al. 2004, MNRAS, 348,316 16

SALTICAM light curves of SDSS J015543.30+002807.2

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