Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

The complex and variable X-ray The complex and variable X-ray spectraspectra

of the super-soft source of the super-soft source RXJ0513.9-6951RXJ0513.9-6951

Vadim Burwitz (MPE)X-ray Grating Spectroscopy Workshop

Cambridge MA, July 12, 2007

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

Talk Overview

Super Soft X-Ray Binaries (SSXBs) RXJ0513.9-6951

Observations of RXJ0513.9-6951 LETGS observations XMM RGS / EPIC

Comparison with other SSXBs

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

White dwarfs at high accretion rates

Eddington rate

Red Giant configuration

Steady H-burn.

non-mass ejecting outbursts (recurrent sources)

Novae

Cassisi et al. 1998

SSXBs

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

Discovery of SSXBs in LMC• X-ray survey of LMC by Einstein Cal 83 & Cal 87 discovered 1st SSXBs

Long, Helfand Grabelsky 1981, Columbia Astrophysics Laboratory

• ROSAT

RX J0513.9-6951 among a total 12 sources

• XMM-Newton

Four new super-soft X-ray sources

Kahabka, Haberl et al. 2006, 2007

SSXBs as accreting binaries

CAL 83

RX J0513-69

CAL 87Our Sun for comparison van Teeseling, Kube

mB = 16.2 mag

Porb=0.76 days

I ~ edge on

mB = 16.2-16.9 mag

Porb= 1.04 days

i = 25 deg

mB = 19 mag

Porb=10.6 hours

I ~ edge on

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

RXJ0513-69: long term optical lightcurve

Southwell et al. 1996

RXJ0513-69: X-ray and

optical variability

Reinsch et al. 2000

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

RX J0513-69: long-term variation model Hachiso & Kato 2003

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

RX J0513-69: SMARTS monitoring 2005

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

RX J0513-69: fits to LETGS dataBlackbody model (30-40 eV, L~1038 erg/s)

Single LTE WD model Two LTE WD models

Burwitz et al. 2007

Planckian model + 4 and more Gaussians ...

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

RX J0513-69 LETGS spectra

Burwitz et al. in prep.

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

RGS-Spectra of RXJ0513.9-6951

McGowan et al. 2005

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

Comparison with the Hachisu and Kato Models

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

RX J0513-69 vs. other Super-soft sources

λ (Å)

Fλ

(erg

/ cm

2 / s

/ Å

)

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

LETGS eclipse spectrum of Cal 87

• O VII Resonance line

• O VIII Ly a red shifted & double peaked

Wind outflow 2200 km/s

• Fe XVII recombination emm.

• resonant scattering • recombination• recombination continua

Greiner et al. 2004

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

XMM-Newton and Chandra observations of Cal 83 Paerels et al. 2001 Lanz et al. 2005

- RGS

- LETGS

Vadim Burwitz X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007

Summary

Optical Monitoring (SMARTS) •For triggering TOOs (Chandra/XMM)

•To study the long-term behavior of these objects

X-ray observations of SSXBs•Needed to study the nature of the outbursts

•RXJ0513.9-6951 evolution during X-ray bright state

WD Atmosphere modeling•Possibly more atomic transitions need to be included

•NLTE vs. LTE

Comparison with theoretical Models