Mari Kolehmainen&

Chris DoneDurham University

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• Currently two methods• shape of the Fe line from reflected emission• continuum fitting of disc dominated spectra

• GX 339-4 widely studied in terms of Fe line• burst mode (non-piled up) spectra give

a*= 0.935 with i≈20°(Reis et al. 2008; Miller et al. 2008)

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• Multi-colour disc blackbody• Disc emission ~80 % of the total emission in the disc

dominated state• Restricted to stellar-mass BHs as AGNs peak in the

UV

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log ν f(ν)

log ν

GX 339-4

• A lot of RXTE data available• all spectral states observed

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• Luminosity relates to the observed flux via

where

is the area of the inner disc

constant emitting area, constant disc inner radius

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GX 339-4

, (Rg=GM/c2)

• Luminosity relates to the observed flux via

where

is the area of the inner disc

constant emitting area, constant disc inner radius

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GX 339-4

, (Rg=GM/c2)

• Limit parameters from the mass functionfM=5.8 ± 0.5M (Hynes et al. 2003)

• 5.8 < M< 15 M

D > 6 kpc 45°< i < 70°

• The inner radius rin

2 > 62/(152 cos 45°) gives an upper limit for a*

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• Disc not accurately described by simple models • stress-free inner boundary condition• colour-temperature correction fcol

• relativistic effects

• We apply these corrections to the simple models to illustrate the effect on spin

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Likely:M= 10 M

D= 8 kpci= 60°

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Max spin:M= 15 M

D= 6 kpci= 45°

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• BHSPEC (Davis et al. 2005)• N-T stress-free inner boundary condition• self-consistently calculates fcol and the

radiative transfer through each disc annuli• includes all the relativistic corrections

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Likely:M= 10 M

D= 8 kpc

i= 20°i= 40°i= 60°

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Likely:M= 10 M

D= 8 kpc

i= 20°i= 40°i= 60°

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Likely:M= 10 M

D= 8 kpc

i= 20°i= 40°i= 60°

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• Δθ ≈ 20°- 30° asymmetric supernova

(Fragos et al. 2010)

Δθ

a* < 0.9 for any reasonable mass (<15M), distance (>6 kpc) and inclination (i > 45°)

Lower mass and/or larger distance and/or higher inclination will give lower spin

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Max spin:M= 15 M

D= 6 kpci = 45°

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Fe line? Disc?

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

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• We constrain limit parameters from the mass function of Hynes et al. (2003):

• Inserting M2=0.166 M and Mx=15 M gives i=45°

•(Muñoz-Darias et al. 2008)

=5.8±0.5M

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a*=0

a*=0.8

a*=0.7

a*=0.9

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• Specific angular momentum, described as a dimensionless parameter a*

• Drags the accretion disc inwards

• a* : 0 - 0.998

Rin : 6 - 1.23 Rg

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• We derive an upper limit of 0.9 for spin in GX 339-4

• Discrepancy between the two methods, Fe line spin higher (and inclination lower) than from continuum fitting

• Lower spin from disc spectral fitting seems more likely so Fe line profile probably not yet completely understood

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• Hard to see how disc spectral fitting is wrong!• L-T4, disc emission dominant,

• Fe line spin too high for supernovae collapse models (Gammie et al. 2004)

• Inclination too low (big misalignment from orbit) for binary formation models

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