Probing general relativistic precession with tomography and polarimetry

Transcription

1 Probing general relativistic precession with tomography and polarimetry Adam Ingram Michiel van der Klis, Matt Middleton, Chris Done, Diego Altamirano, Phil Uttley, Magnus Axelsson, Tom Maccarone, Juri Poutanen, Henric Krawczynski, Matthew Liska, Casper Hesp, Sasha Tchekhovskoy, Sera Markoff X-ray Universe - Rome

2 Black hole X-ray binaries 2 ~100 km Black Hole X-ray Binaries ~100 km Unique laboratories for strong field GR Probe relativistic motions of orbiting material in strong gravitational fields Black hole ~ 10 Solar masses Too small to directly image Black hole ~ Solar masses

3 Black hole X-ray binaries 3 Multi-temperature blackbody, Comptonisation and Reflection Flux Flux Energy (kev) e.g. Done, Gierlinski & Kubota (2007)

4 Continuum Reflection Reflection 4 Flux Energy (kev) Fabian et al (1989); Matt, Fabian & Ross (1993)

5 Spectral states 5 Flux Soft State Energy (kev) Flux Hard State Energy (kev) 3-10 kev Flux Flux Hard State Energy (kev) Hardness ratio e.g. Done, Gierlinski & Kubota (2007); plots: Plant et al (2014)

6 Spectral states 6 R in ~ISCO R in >ISCO? 3-10 kev Flux R in >ISCO Hardness ratio e.g. Done, Gierlinski & Kubota (2007); plots: Plant et al (2014)

7 Quasi-periodic oscillations (QPOs) 7 QPO period moves from ~ s as spectrum gets softer X ray Brightness Time (s)

8 Frame dragging 8 The spin of the black hole influences the satellite orbit Precession frequency ~ r -3 Lense & Thirring (1918) Stella & Vietri (1998)

9 Frame dragging 9 H/R > α H/R < α Credit: Matthew Liska Solid body precession at average LT frequency Fragile et al (2007); Liska et al (in prep) Viscosity aligns inner regions with the BH and outer regions with the binary partner Bardeen & Petterson (1975)

10 Frame dragging 10 X ray Brightness QPO in GRS Time (s) Ingram, Done & Fragile (2009)

11 Frame dragging 11 Tell-tale sign of precession: a rocking iron line Flux Ingram & Done (2012); Schnittman et al (2006) Energy

12 Precession in H ratio XMM Newton ratio NuSTAR Energy (kev) Energy (kev) Ingram et al (2016)

13 Interpretation 13 QPO phase ~ 0.4 cycles QPO phase ~ 0.5 cycles QPO phase ~ 0.7 cycles QPO phase ~ 0.75 cycles Flux ( kev cm 2 s 1 ) QPO phase = 0.75 cycles QPO phase ~ 0.7 cycles QPO phase ~ 0.4 cycles QPO phase = 0.5 cycles 6 8 Energy (kev) Ingram et al (2017)

14 Tomographic modeling 14 Parameterize disk illumination: r in = GM/c 2 i = degrees Ingram et al (2017)

15 Polarization 15 R o =20R g, a=0.98 Flux Predict swings in polarization angle p (%) χ (degrees) ψ log 10 (flux) QPO cycles Ingram et al (2015)

16 X-ray polarimetry-timing 16 IXPE NASA SMEX Launch: late 2020 incoming photon detector

17 ψ 0 = polarisation angle ψ = modulation angle X-ray polarimetry-timing North on projected sky 17 ψ ψ 0 incoming photon

18 ψ 0 of population X-ray polarimetry-timing North on projected sky 18 ψ ψ 0 p 0

19 X-ray polarimetry-timing 19 Can we make a time series? X ray Brightness ψ 0? IXPE count rate ~ 100 c/s p 0 of source < ~10% Integration time: T ~ 4 minutes! So can t probe variability on timescales of seconds Time (s)

20 X-ray polarimetry-timing 19 Can we make a time series? X ray Brightness ψ 0? Time (s) IXPE count rate ~ 100 c/s p 0 of source < ~10% Integration time: T ~ 4 minutes! Can use phase-folding for periodicities like pulses, but NOT for QPOs and noise

21 X-ray polarimetry-timing 20 ψ 0 varies: peak of distribution varies p 0 varies: amplitude of distribution varies Ingram & Maccarone (in prep)

22 X-ray polarimetry-timing 21 Counts / radian Phase (QPO cycles) Can measure the amplitude and phase of each of these light curves using standard cross-spectral techniques Ingram & Maccarone (in prep)

23 X-ray polarimetry-timing 22 ψ 0 (degrees) p (%) Flux QPO cycles Ingram & Maccarone (in prep) Fractional RMS (%) Phase (cycles) ψ (degrees)

24 X-ray polarimetry-timing 23 Simulated 200 ks IXPE exposure: Proposed missions: Fractional RMS (%) XIPE (ESA M4 candidate): 2 area = even better extp (Chinese-led): 2-5 area + large area detector = even better still! Phase (cycles) Ingram & Maccarone (in prep) ψ (degrees)

25 Jet precession 24 Liska, Hesp, Tchekovskoy, Ingram et al (in prep)

26 Conclusions 25 The centroid energy of the iron line in H is modulated on the QPO frequency => LT precession! First instance of tomographic mapping X-ray polarimetry-timing provides orthogonal test and powerful probe of the accretion geometry This should be possible with IXPE XIPE and extp will be even better! Method not just for QPOs: any kind of stochastic variability! Predict jet precession with high-res GRMHD simulations