Time Domain Astrophysics Stephen Potter South African Astronomical

Time Domain Astrophysics Stephen Potter South 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 2

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) ke. V/Me. V emission + – variability as fast as milliseconds 3

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

7

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

Doppler Tomography 9

Roche Tomography Potter, Romero-Colmenero, Watson, Buckley, Phillips 2004, MNRAS, 348, 316 10

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 13

Targets of opportunity Doppler Tomography Steeghs, D. , Harlaftis, E. T. , Horne, K. , 1999, MNRAS, 306, 348 14

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 J 015543. 30+002807. 2 17

18

19