Modelling the high mass accretion rate spectra of GX Mari Kolehmainen & Chris Done Durham University Maria Diaz Trigo, ESO High Energy View of Accreting Objects: X-ray Binaries Agios Nikolaos, Crete 2010

High mass accretion rate spectra classical high/soft state ▫disc dominated ▫measure BH spin from disc continuum very high/intermediate state ▫strong hard X-ray tail ▫measure BH spin from Fe-line profile 2

Beyond the RXTE energy band 3 GX keV

GX < M< 15 M  D > 6 kpc 45°< i < 70° Loads of RXTE data (> 3 keV) Few XMM-Newton EPIC-pn Burst mode observations (> 0.7 keV) ▫not piled up! 4

EPIC-pn Burst mode Time resolution 7μs Timing mode 30μs (800 counts/s) Pileup limit 60,000 counts/s Duty cycle 3 % photon collecting time/readout time Extracted using SAS10 includes CTI correction 5

Burst mode observations of GX joint EPIC-pn/RXTE observations 2 disc dominated states 2 soft intermediate states (SIMS) 6

Burst mode observations of GX M = 10 M  D = 8 kpc i = 60° (SIMS) (discy) (SIMS) (discy) 7 Kolehmainen & Done (2010)

3 keV DISKBB simplest multi-colour disc blackbody KERRBB stress-free inner boundary condition, relativistic smearing and the colour- temperature correction BHSPEC calculates radiative transfer through each disc annuli includes all the relativistic corrections assumes R in =R ISCO Continuum fitting below 3 keV: Disc dominated state 8

Disc model ▫use this as seed photons for Comptonisation (convolved with Simpl (Steiner et al. 2009)) to make X-ray tail reflection of Comptonised continuum using ionised reflection models of Ross & Fabian relativistic smearing (kdblur) 9

Continuum fitting below 3 keV: Disc dominated state 10 diskbb+reflection ▫very steep continuum to make disc broader  Γ > 3 ▫reflection fraction ~4 ▫misses HEXTE

Continuum fitting below 3 keV: Disc dominated state 11 diskbb+reflection ▫very steep continuum to make disc broader  Γ > 3 ▫reflection fraction ~4 ▫misses HEXTE

Continuum fitting below 3 keV: Disc dominated state 12 diskbb+CompTT+ reflection ▫Γ~2.4 ▫reflection fraction~0.4 ▫extrapolates to HEXTE

Continuum fitting below 3 keV: Disc dominated state 13 diskbb+CompTT+ reflection ▫Γ~2.4 ▫reflection fraction~0.4 ▫extrapolates to HEXTE

Continuum fitting below 3 keV: Disc dominated state 14 bhspec+reflection ▫Γ~2.3 ▫reflection fraction ~0.9 ▫extrapolates to HEXTE ▫does not allow SIMS fitting

Continuum fitting below 3 keV: Disc dominated state 15 bhspec+reflection ▫Γ~2.3 ▫reflection fraction ~0.9 ▫extrapolates to HEXTE ▫does not allow SIMS fitting

Continuum fitting past the disc dominated state: The model tbabs*((diskbb*simpl)+CompTT+kdblur*refxion*(simpl*diskbb)) a major advantage comes from being able to fit with different mass accretion rates 16 disc dominated

Continuum fitting past the disc dominated state: The model tbabs*((diskbb*simpl)+CompTT+kdblur*refxion*(simpl*diskbb)) a major advantage comes from being able to fit with different mass accretion rates 17 SIMS

The soft intermediate state (SIMS) 20-25% of disc up-scattered to produce tail photon index 2.44 no high energy roll-over frac. of reflected emission ~0.5 R in ~ 70R g highly ionised  So what about the Fe-line? 18 Obsid

Previously derived an upper limit of 0.9 for the spin in GX from continuum fitting of disc dominated RXTE spectra GX widely studied in terms of Fe-line burst mode spectrum gave a * = (Miller et al. 2004; Reis et al. 2008) The Fe-line and the BH spin 19

The Fe-line and the BH spin diskbb+po+reflection disc, power law, ionised smeared reflection continuum modelled by ignoring 4−7 keV  Residuals show a broad iron line 20 Obsid

The Fe-line and the BH spin diskbb+compTT+reflection convolved disc, compTT, ionised smeared reflection  Narrow line does not constrain BH spin 21 Obsid

Conclusions The XMM-Newton Burst mode can actually be used to make science ▫can look at the disc below 3 keV even with the brightest objects Real disc spectra are much broader than diskbb Changing the continuum model changes the shape of the iron line (and the BH spin) 22