Transcript Super Soft X-ray sources

The complex and variable X-ray
spectra
of the super-soft source
RXJ0513.9-6951
Vadim Burwitz (MPE)
X-ray Grating Spectroscopy Workshop
Grating Spectroscopy, Cambridge, MA, July 12, 2007
Vadim Burwitz CambridgeX-ray
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
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
Vadim Burwitz
X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007
SSXBs as accreting binaries
mB = 16.2 mag
mB = 16.2-16.9 mag
Porb=0.76 days
Porb= 1.04 days
I ~ edge on
i = 25 deg
RX J0513-69
CAL 83
mB = 19 mag
Porb=10.6 hours
I ~ edge on
Our Sun for
comparison
CAL 87
van Teeseling, Kube
RXJ0513-69: long term optical lightcurve
Southwell et al. 1996
Vadim Burwitz
X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007
RXJ0513-69:
X-ray and
optical
variability
Reinsch et al. 2000
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 data
Blackbody model (30-40 eV, L~1038 erg/s)
Single LTE WD model
Planckian model + 4 and more Gaussians
...
Two LTE WD models
Burwitz et al. 2007
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
Fλ (erg / cm2 / s / Å)
RX J0513-69 vs. other Super-soft sources
λ (Å)
Vadim Burwitz
X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007
LETGS eclipse spectrum of Cal 87
Greiner et al. 2004
• 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
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
Vadim Burwitz
X-ray Grating Spectroscopy, Cambridge, MA, July 12, 2007