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MODEL SETUP 7Resonant scattering(Schönherr et al. 2007 after Araya & Harding 1999based on calculations by Sina 1996)Cyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


MODEL SETUP 8The „response function of the line forming region“:Energy redistributionCyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


MODEL SETUP 9Spectrum: Green‘s functions approachConvolve with Green‘s functionsArbitrary continuumFinal spectrumwith linesCyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


SIMULATED LINE SHAPES 10Variation with the magnetic field B0.080.070.060.0520 40 60 80 100 200Energy [keV](Schönherr et al. 2007)Cyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


SIMULATED LINE SHAPES 11Temperature dependence2015105Trümper et al. 1978:20 40 60 80 100Energy [keV](Schönherr et al. 2007)Cyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


Variation with μ and ττ 1 τ 2SIMULATED LINE SHAPES 12μ20 40 60 100 20 40 60 100Energy [keV]Energy [keV](Schönherr et al. 2007)Cyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


Variation with the geometrySIMULATED LINE SHAPES 1320 40 60 100 20 40 60 100Energy [keV]Energy [keV]20 40 60 100 20 40 60 100Energy [keV]Energy [keV]20 40 60 100 20 40 60 100Energy [keV]Energy [keV](Schönherr et al. 2007)Cyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


FITTED LINE SHAPES 14Does cyclomc fit nature?normalized counts/sec/keVΔχΔχ10 −110 −210 −310 −4420−2−4420−2−44U1907+09(Suzaku)20 30 40Energy [keV]Δχ normalized counts/sec/keVΔχ ΔχΔχ ΔχΔχ Δχ10 110 010 −110 −210 −310 −45−55−5−55−5−55−5−5V0332+53(INTEGRAL)30 40 50 60 7030 40 50 60 70Energy [keV](a)(b)(c)(c)(d)(d)(e)(e)Easy: one lineComplicated: several linesCyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


Beyond Gaussian modelling…COMPARISON TO DATA 15Expectations / Model features– predict line positions for given B (≈Gaussian)– predict line profiles depending on physical setting andgiven continuum (>Gaussian)– Model several lines simultanously (>Gaussian)Outcome– Magnetic field + Indications for field structure– B + temp., geometry, angle– Line ratios + impossible line ratios-> physics!Cyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


Beyond Gaussian modelling…Physical parameter correlations?COMPARISON TO DATA 164U1907+09(Suzaku)V0332+53(INTEGRAL)Cen X-3(RXTE)10 −110 1normalized counts/sec/keVΔχΔχ10 −210 −310 −4420−2−4420−2−420 30 40Energy [keV]1412108V0332+53Cen X−3normalized counts/sec/keVΔχΔχ10 010 −110 −210 −310 −450−550−530 40 50 60 70Energy [keV]64U 1907+09415 20 25 30 35E[Lamb 1990]Cyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)


SUMMARY AND OUTLOOK 17Conclusions and a quick outlook…Cyclotron line analysis provides an elegant way to probe themagnetic field and the physics of accretion ofneutron starscyclomc• Variation of position with pulse phase NOT predicted by anangular variation bulk velocity? Geometry change?• No emission wings bottom illuminated slab geometry,possibly gradients to smear out lines!• Modelled lines deeper than observed, fitting multiple line(positions) problematic B-field structureStill many d.o.f. where do we go?• More fitting / sources / statistics• Parallel cross-checks, e.g., depth&cross sections withother models (Isenberg, Nishimura, etc.) B-field structureimplementationCyclotron lines in accreting X-ray pulsars – ESAC - August 2008 – G. Schönherr (AIP)

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