Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

Cross-calibration results from observations of the

INS RX J1856RX J1856, and theWDs HZ 43HZ 43 and Sirius BSirius B

Vadim Burwitz

EPIC CAL/OPS May 4-5 2006, MPE

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

Overview Absolute Calibration Soft X-rays

dependant on model spectra of WDs

what models to use?, uncertainties?

Analyse LETG + HRC-S data HZ 43A, Sirius B and RX J1856.5-3754

determine spectral parameters

improve effective area.

Compare obtained photon spectra with EUVE and ROSAT

and XMM (work by Frank Haberl)

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

NLTE pure H model spectrum of HZ43

Different bound-free and free-free absorption coefficients

-- Seaton

-- Karzas & Latter

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

NLTE pure H model spectrum of HZ43

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

HZ43 temperature vs. gravity

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

RX J1856-37 two temperature bb fit

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

RX J1856-37 two temperature bb fit

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

Simultaneous fit to RXJ1856 and the WDs

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

Simultaneous fit to RXJ1856 and the WDs

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

LETG + HRC-S effective areas

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

Parameters obtained from fit

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

Comparison of photon spectra

EUVE

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

RX J1856.5–3754: A `stable‘ neutron star

Individual fits

with

all parameters

free:

Simu

ltaneous fits

with

NH lin

ked:

Model:tbabs*bbody

from Frank Haberl

Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006 Vadim Burwitz EPIC CAL/OPS, MPE May 4, 2006

Summary