Swift observations of 4U 1957+11

Fluxes obtained with simple disk plus power law model

Setup for relativistic disk modeling

Different values of mass, distance and inclination were chosen:
 Mass/Msun: 5, 10, 15
 Dist/kpc: 5, 10, 15, 20
 incl/deg: 55, 65, 75, 85

=>48 {M, d, i} triplets.

Model: phabs*kerrbb

 Frozen parameters:
  kerrbb.eta=0 (standard Keplerian disk with zero torque at the inner boundary),
  kerrbb.Mbh=one of the choices from above,
  kerrbb.dist=one of the choices from above,
  kerrbb.incl=one of the choices from above,
  kerrbb.rflag=1 (self-irradiation is included),
  kerrbb.lflag=1 (limb-darkening is included).

 Global parameters (allowed to vary, but tied between observations):

 Local parameters (allowed to vary between observations):
  kerrbb.Mdd (mass accretion rate of the disk in units of 10^18 g/sec),
  kerrbb.hd (spectral hardening factor).

Number of free parameters in the simultaneous fits = 54
Degrees of freedom = 14,822

Fit results

   * Click here to see variation of mass accretion rate and spectral hardening (color correction) factor.
   * Click here to see individual fits.
   * Click here to see individual best-fit parameter files.

Heat maps ...

... based on reduced-χ2 values (i.e. χ2ν2/14822)

... based on derived spin values

...based on values of averaged spectral hardening factors

... based on values of average best-fit Eddington luminosities

... heat maps based on isotropic Eddington luminosities assuming a flux of 1.5x10-9 erg/s/cm^2.

... based on derived column density


Chernoff faces for {M,D,i} triplets

Control faces

The leftmost face is a `neutral' face where the parameter values of
  L/LEdd (characterized by the oblateness of the face),
  χ2 (roundness of the eyes),
  a* (inclination of the eyebrows), and
  hd (mouth curvature)
are all near the middle of their respective colorbars shown in the heat maps above.

The remaining figures show how the faces/expressions change when any one of these parameters above change.

Mass=5 solar

Mass=10 solar

Mass=15 solar

Last update: 2013 June 05 (DM).