Model: Mike Truss Visualisation: Richard West

Accretion in non-magnetic cataclysmic variables

Peter Wheatley

University of Warwick

Still et al 2010V344 Lyr

Kepler GO highlight

RXTE ASMRemillard et al 2009

X-ray transients

Ricketts, King & Raine 1979SS Cyg with Ariel V

Wheatley, Mauche & Mattei 2003

outburstquiescence

Patterson & Raymond 1985

Mukai et al., 2003Chandra HETG spectra

Mukai et al., 1997HT Cas eclipse with ASCA

Z Cha with XMM-Newton

Hickman, Wheatley et al. 2010

Optical: B band

0.2-12 keV

WD eclipse

Z Cha optical eclipse Hickman, Wheatley et al. 2010

B band

1.2-10 keV

0.2-1.2 keV

Hickman, Wheatley et al., 2010Z Cha X-ray eclipse

X-ray spectra

quiescence outburst

Patterson & Raymond 1985

Confirmed

SU UMa Collins & Wheatley 2009

4x1015g/s

Hamuery et al

Collins & Wheatley 2009

X-ray spectra

quiescence outburst

Patterson & Raymond 1985

Confirmed

Naylor et al. 1988OY Car in outburst with EXOSAT LE

7-250 Å

Chandra EUV spectra of dwarf novae in outburstMauche 2004

WZ Sgehigh inclination

SS Cyglow inclination

Lbl~1034 erg s-1 NH~3x1019 cm-2 V~2500 km s-1

X-ray spectra

quiescence outburst

Patterson & Raymond 1985

Confirmed Confirmed

NH~3x1019 cm-2

QPOs in dwarf nova outburstsMauche 2004

Belloni et al 2002

Mauche 2004

Warner & Woudt 2002

X-ray spectra

quiescence outburst

Patterson & Raymond 1985

Confirmed Confirmed

NH~3x1019 cm-2

?

Z Cha in outburst with XMM-Newton

outburst

quiescence

XMM-Newton spectra of Z Cha

outburst

quiescence

Outburst spectrum

Origin of outburst X-rays?

Lx <= 10-3 LBol

MRI-driven accretion disc corona? Shocks in outflows/jets?

Knigge et al 1997Z Cam with HUT

Koerding et al 2008

Okada et al 2008SS Cyg in outburst and quiescence

MAXI

Revnivtsev et al 2006

Sazonov et al 2006X-ray luminosities of SDSS-selected CVsReis, Wheatley et al 2010

Swift

Galactic ridge X-ray emission

Revnivtsev et al 2009

Byckling et al 2010

Summary

• Disc instability model:– under predicts quiescent accretion rate by >100x

– fails to explain outbursts in SS Cyg

• Origin of outburst X-ray emission unknown– MRI-driven corona?

– Shocks in outflows/jets?

• Jets, outflows and QPOs all detected in CVs– models for BHs/NSs must also work for white dwarfs

• Galactic ridge X-ray emission:– contribution of non-magnetic CVs previously underestimated