J/MNRAS/468/4735 Spectral evolution of 4U 1543-47 in 2002 (Lipunova+, 2017)
Determination of the turbulent parameter in accretion discs:
effects of self-irradiation in 4U 1543-47 during the 2002 outburst.
Lipunova G.V., Malanchev K.L.
<Mon. Not. R. Astron. Soc., 468, 4735-4747 (2017)>
=2017MNRAS.468.4735L 2017MNRAS.468.4735L (SIMBAD/NED BibCode)
ADC_Keywords: Accretion ; Binaries, X-ray ; X-ray sources
Keywords: accretion, accretion discs - methods: numerical - binaries: close -
stars: black holes - X-rays: individual: 4U 1543-47
Abstract:
We investigate the viscous evolution of the accretion disc in 4U
1543-47, a black hole binary system, during the first 30 d after the
peak of the 2002 burst by comparing the observed and theoretical
accretion rate evolution dM(t)/dt. The observed dM(t)/dt is obtained
from spectral modelling of the archival Proportional Counter Array
aboard the RXTE observatory (RXTE/PCA) data. Different scenarios of
disc decay evolution are possible depending on a degree of
self-irradiation of the disc by the emission from its centre. If the
self-irradiation, which is parametrized by factor Cirr, had been as
high as ∼5x10-3, then the disc would have been completely ionized up
to the tidal radius and the short time of the decay would have
required the turbulent parameter α∼3. We find that the shape of
the {dot}M(t) curve is much better explained in a model with a
shrinking high-viscosity zone. If Cirr~(2-3)x10-4, the resulting
α lie in the interval 0.5-1.5 for the black hole masses in the
range 6-10M☉, while the radius of the ionized disc is variable
and controlled by irradiation. For very weak irradiation,
Cirr<1.5x10-4, the burst decline develops as in normal outbursts
of dwarf novae with α∼0.08-0.32. The optical data indicate that
Cirr in 4U 1543-47 (2002) was not greater than approximately
(3-6)x10-4. Generally, modelling of an X-ray nova burst allows one
to estimate α that depends on the black hole parameters. We
present the public 1D code FREDDI to model the viscous evolution of an
accretion disc. Analytic approximations are derived to estimate
α in X-ray novae using dM(t)/dt.
Description:
Evolution of the spectral parameters obtained from the fitting of the
spectral data obtained with RXTE/PCA in the 2.9-25keV energy band.
Some spectral parameters are plotted in Figure 1 of the paper. The
black hole mass is 9.4 solar masses, the Kerr parameter is 0.4, the
disc inclination is 20.7 grad. The spectral fitting is done using
XSPEC 12.9.0. The XSPEC spectral model consists of the following
spectral components: TBabs((simpl*kerrbb+laor)smedge). Full
description of the spectral parameters can be found in Table A1 and
Appendix A of the paper.
Objects:
------------------------------------------------
RA (2000) DE Designation(s)
------------------------------------------------
15 47 08.6 -47 40 10 4U 1543-47 = V* IL Lup
------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
figure1.dat 302 58 Evolution of spectral parameters of
4U 1543-47 during the 2002 outburst
--------------------------------------------------------------------------------
Byte-by-byte Description of file: figure1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- ObsID Observation ID (1)
17- 32 F16.8 s tbegin Observation start (Julian date)
34- 49 F16.8 s tend Observation end (Julian date)
51- 57 F7.4 --- chi2 Chi-square of the spectral fit (2)
59- 60 I2 --- dof Number of degrees of freedom of the
spectral fit (3)
62- 71 E10.5 mW/m2 FDisc-min Lower boundary of 1-sigma confidence
interval on the disc flux (4)
73- 82 E10.5 mW/m2 FDisc-max Upper boundary of 1-sigma confidence
interval on the disc flux (4)
84- 93 E10.5 mW/m2 FTot-min Lower boundary of 1-sigma confidence
interval on the total flux (5)
95-104 E10.5 mW/m2 FTot-max Upper boundary of 1-sigma confidence
interval on the total flux (5)
106-112 F7.5 --- Gamma Best-fit value of the photon power law index
in the spectral component simpl
114-120 F7.5 --- b_Gamma Lower boundary of 1-sigma confidence
interval for Gamma
122-128 F7.5 --- B_Gamma Upper boundary of 1-sigma confidence
interval for Gamma
130-136 F7.5 --- FracSctr Best-fit value of the scattered fraction in
the spectral component simpl
138-144 F7.5 --- b_FracSctr Lower boundary of 1-sigma confidence
interval for FracSctr
146-152 F7.5 --- B_FracSctr Upper boundary of 1-sigma confidence
interval for FracSctr
154-161 F8.5 10+18g/s dotM Best-fit value of the mass accretion rate of
the disc in the spectral component kerrbb
163-170 F8.5 10+18g/s b_dotM Lower boundary of 1-sigma confidence
interval for dotM
172-179 F8.5 10+18g/s B_dotM Upper boundary of 1-sigma confidence
interval for dotM
181-188 F8.5 kpc dist Best-fit value of the distance in the
spectral component kerrbb (6)
190-197 F8.5 kpc b_dist ?=99.99 Lower boundary of 1-sigma confidence
interval for dist (6)
199-206 F8.5 kpc B_dist ?=99.99 Upper boundary of 1-sigma confidence
interval for dist (6)
208-214 F7.5 keV LineE Best-fit value of the line energy in the
spectral component laor
216-222 F7.5 keV b_LineE ?=0 Lower boundary of 1-sigma confidence
interval for LineE
224-230 F7.5 keV B_LineE ?=0 Upper boundary of 1-sigma confidence
interval for LineE
232-238 F7.5 ph/cm2/s norm Best-fit value of the photon flux in the
spectral component laor
240-246 F7.5 ph/cm2/s b_norm ?=99.99 Lower boundary of 1-sigma confidence
interval for norm
248-254 F7.5 ph/cm2/s B_norm Upper boundary of 1-sigma confidence
interval for norm
256-262 F7.5 keV edgeE Best-fit value of the threshold energy in
the spectral component smedge
264-270 F7.5 keV b_edgeE ?=99.99 Lower boundary of 1-sigma confidence
interval for edgeE
272-278 F7.5 keV B_edgeE Upper boundary of 1-sigma confidence
interval for edgeE
280-286 F7.5 --- MaxTau Best-fit value of the maximum absorption
factor at threshold in the spectral
component smedge
288-294 F7.5 --- b_MaxTau ?=99.99 Lower boundary of 1-sigma confidence
interval for MaxTau
296-302 F7.5 --- B_MaxTau Upper boundary of 1-sigma confidence
interval for MaxTau
--------------------------------------------------------------------------------
Note (1): Some rows have the same ObsID because an original observation
was divided in two parts.
Note (2): The XSPEC spectral model consists of the following spectral
components: TBabs((simpl*kerrbb+laor)smedge). Full description of the
spectral parameters can be found in Table A1 and Appendix A of the paper.
Note (3): The number of the degrees of freedom depends on whether the parameter
dist of the spectral component kerrbb is fixed or not (see also the caption
of Figure 1 in the paper).
dof=40 if the distance to the source was estimated during fitting,
dof=41 if the distance was fixed. The number of the spectral channels
is 49 for all observations. The total number of the spectral model
parameters, free and frozen, is 24.
Note (4): The model flux before absorption in the energy band 0.05-50 keV
of the following spectral model components: (kerrbb+laor)smedge.
Note (5): The model flux before absorption in the energy band 0.05-50 keV
of the following spectral model components:
(simpl*kerrbb+laor)smedge.
Note (6): If the lower and upper boundaries of parameter dist are
unspecified, this means that the distance was fixed during fitting.
--------------------------------------------------------------------------------
Acknowledgements:
Galina V. Lipunova, galja(at)sai.msu.ru
(End) G. Lipunova [Sternberg Astron. Inst. MSU], P. Vannier [CDS] 08-Aug-2017