J/ApJ/376/161 X-ray spectra of bursting neutron stars (Madej+, 1991)
Model atmospheres and X-ray spectra of bursting neutron stars.
Madej J.
<Astrophys. J., 376, 161-176 (1991)>
=1991ApJ...376..161M 1991ApJ...376..161M
ADC_Keywords: Models, atmosphere ; Binaries, X-ray
Keywords: radiative transfer - stars: atmospheres - stars: neutron -
X-rays: bursts
Abstract:
X-ray burst sources represent a class of accreting neutron stars in
close binary systems which do not exhibit any traces of the magnetic
field. We present new method of hot model atmosphere computations with
account of Compton scattering on free electrons and computed set of
plane-parallel hydrogen-helium atmospheres and X-ray spectra of
bursting neutron stars.
Models were computed with precise angle-dependent radiative transfer
under constrains of radiative and hydrostatic equilibrium. Compton
scattering opacity included both the Klein-Nishina corrections and the
effects of relativistic Maxwellian thermal motion of scattering
electrons. Compton redistribution function allows for large energy
exchange between X-ray photons and scattering electrons.
Description:
Grid consists of 20 continuum X-ray spectra of hot model atmospheres
computed for the single hydrogen-helium chemical composition with the
helium number abundance He/H=0.11 (solar value). Model atmospheres and
spectra were computed for effective temperatures Teff=8x106,
1.257x107, 2x107 and 3x107K and various surface gravities
logg=12.5 to 15.0 (g in units cm/s2).
File 'table1.dat' presents values of model parameters and
corresponding spectral hardening factors, Tcol/Teff. Also critical
gravity g_cr was estimated for each value of T_eff.
Values of effective temperatures Teff, gravities logg and fluxes are
measured on the neutron star surface.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 4 *Model parameters and fc=Tcol/Teff ratios
(spectral hardening factor)
table2.dat 59 200 Photon energy and fluxes
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Note on table1.dat: Parameters of neutron star model atmospheres and spectra.
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See also:
J/AcA/41/73 : Model atmospheres of X-ray bursting neutron stars (Madej, 1991)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 I1 --- nr [1/4] Index of effective temperature
3- 11 E9.3 K Teff Corresponding effective temperature
(8.00E+06, 1.257E+07, 2.00E+07, 3.00E+07)
13- 18 F6.3 [cm/s2] loggcr [12.39/14.65] Logarithm of critical gravity
20- 24 F5.2 [cm/s2] logg1 [15] Logarithm of surface gravity 1
26- 29 F4.2 --- fc1 [1.36/1.41] Spectral hardening factor for logg1
31- 35 F5.2 [cm/s2] logg2 [14.5/14.8] Logarithm of surface gravity 2
37- 40 F4.2 --- fc2 [1.36/1.48] Spectral hardening factor for logg2
42- 46 F5.2 [cm/s2] logg3 [14.0/14.7] Logarithm of surface gravity 3
48- 51 F4.2 --- fc3 [1.36/1.55] Spectral hardening factor for logg3
53- 57 F5.2 [cm/s2] logg4 [13.5/14.1]? Logarithm of surface gravity 4
59- 62 F4.2 --- fc4 [1.45/1.52]? Spectral hardening factor for logg4
64- 68 F5.2 [cm/s2] logg5 [13.0/14.0]? Logarithm of surface gravity 5
70- 73 F4.2 --- fc5 [1.52/1.58]? Spectral hardening factor for logg5
75- 79 F5.2 [cm/s2] logg6 [12.5/13.2]? Logarithm of surface gravity 6
81- 84 F4.2 --- fc6 [1.62/1.62]? Spectral hardening factor for logg6
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 I1 --- nr [1/4] Index of effective temperature
5- 11 F7.4 keV E [0.058/62.211] Photon energy
14- 19 F6.3 [mW/m2/keV] FE1 ? Log flux FE for logg1
22- 27 F6.3 [mW/m2/keV] FE2 ? Log flux FE for logg2
30- 35 F6.3 [mW/m2/keV] FE3 ? Log flux FE for logg3
38- 43 F6.3 [mW/m2/keV] FE4 ? Log flux FE for logg4
46- 51 F6.3 [mW/m2/keV] FE5 ? Log flux FE for logg5
54- 59 F6.3 [mW/m2/keV] FE6 ? Log flux FE for logg6
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Acknowledgements:
Jerzy Madej, jm(at)astrouw.edu.pl, University of Warsaw
(End) Jerzy Madej [Warsaw], Patricia Vannier [CDS] 28-Nov-2014