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AHELP for CIAO 4.9 Sherpa v1

xsnsmaxg

Context: models

Synopsis

Neutron star with a magnetic atmosphere. XSPEC model.

Description

The xsnsmaxg model interpolates from a grid of neutron star (NS) atmosphere spectra to produce a final spectrum that depends on the parameters listed below. Atmosphere spectra are obtained using the latest equation of state and opacity results for a partially ionized, strongly magnetized hydrogen or mid-Z element plasma. Models are constructed by solving the coupled radiative transfer equations for the two photon polarization modes in a magnetized medium, and the atmosphere is in radiative and hydrostatic equilibrium. Atmosphere models mainly depend on the surface effective temperature T_eff and magnetic field strength B and inclination theta_B; there is also a dependence on the surface gravity g=(1+z_g)GM/R^2, where 1+z_g=(1-2GM/R)^-0.5 is the gravitational redshift and M and R are the NS mass and radius, respectively.

Two sets of models are available: one set with a single surface B and T_eff [some models allow for varying g, in the range log g (cm s^-2) = 13.6-15.4] and a set which is constructed with B and T_eff varying across the surface according to the magnetic dipole model (theta_m is the angle between the direction to the observer and the magnetic axis). Effective temperatures span the range log T_eff (K) ~ 5.5-6.7. Models with single (B,T_eff) cover the energy range 0.05-10 keV, while models with (B,T_eff)-distributions cover the range 0.09-5 keV.

This is an additive model component.

xsnsmaxg Parameters

Number Name Description
1 logteff surface (unredshifted) effective temperature
2 M_ns neutron star gravitation mass (in units of Solar mass)
3 R_ns neutron star radius (km)
4 dist distance to neutron star (kpc)
5 specfile switch indicating model to use
6 norm normalization (though not strictly correct, can be varied to change the size of the emission region, (R_em/R)^2)

The models available by setting the specfile parameter

Value Element B (10^12 G) theta_B theta_m log g (cm/s^2) log T_eff E (keV)
1000 H 0.01 0 N/A 2.4 5.5 - 6.7 0.05 - 10
1060 H 0.04 0 N/A 2.4 5.5 - 6.7 0.05 - 10
1085 H 0.07 0 N/A 2.4 5.5 - 6.7 0.05 - 10
1100 H 0.1 0 N/A 2.4 5.5 - 6.7 0.05 - 10
1200 H 1.0 0 N/A 0.4 - 2.5 5.5 - 6.7 0.05 - 10
1230 H 2.0 0 N/A 2.4 5.5 - 6.8 0.05 - 10
1260 H 4.0 0 N/A 2.4 5.5 - 6.8 0.05 - 10
1280 H 7.0 0 N/A 2.4 5.5 - 6.8 0.05 - 10
1300 H 10.0 0 N/A 0.4 - 2.5 5.5 - 6.7 0.05 - 10
1330 H 20.0 0 N/A 2.4 5.6 - 6.8 0.05 - 10
1350 H 30.0 0 N/A 2.4 5.7 - 6.8 0.05 - 10
1211 H 1.26 0 N/A 1.6 5.5 - 6.8 0.05 - 10
1281 H 7.0 0 N/A 1.6 5.5 - 6.8 0.05 - 10
12006 C 1.0 0 N/A 2.4 5.8 - 6.9 0.05 - 10
13006 C 10.0 0 N/A 2.4 5.8 - 6.9 0.05 - 10
12008 O 1.0 0 N/A 2.4 5.8 - 6.9 0.05 - 10
13008 O 10.0 0 N/A 2.4 5.8 - 6.9 0.05 - 10
12010 Ne 1.0 0 N/A 2.4 5.8 - 6.9 0.05 - 10
13010 Ne 10.0 0 N/A 2.4 5.8 - 6.9 0.05 - 10
123100 H 1.0-1.82 0-90 0 1.6 5.5 - 6.8 0.09 - 5
123190 H 1.0-1.82 0-90 90 1.6 5.5 - 6.8 0.09 - 5
130100 H 5.5-10.0 0-90 0 1.6 5.5 - 6.8 0.09 - 5
130190 H 5.5-10.0 0-90 90 1.6 5.5 - 6.8 0.09 - 5

If you publish results obtained using this model, please reference Ho, W.C.G., Potekhin, A.Y., & Chabrier, G. (2008, ApJS, 178, 102) and also Mori, K. & Ho, W.C.G. (2007, MNRAS, 377, 905) if using the mid-Z models. See Ho, W.C.G. (2014, Proc. of IAUS 302, submitted) for discussion of nsmaxg and nsmax.

XSPEC version

This information is taken from the XSPEC User's Guide. Version 12.9.0o of the XSPEC models is supplied with CIAO 4.9.

Bugs

For a list of known bugs and issues with the XSPEC models, please visit the XSPEC bugs page.

To check the X-Spec version used by Sherpa, use the get_xsversion routine from the xspec module:

sherpa> from sherpa.astro.xspec import get_xsversion
sherpa> get_xsversion()
'12.9.0o'

See Also

models
absorptionedge, absorptiongaussian, absorptionlorentz, absorptionvoigt, accretiondisk, atten, bbody, bbodyfreq, beta1d, beta2d, blackbody, box1d, box2d, bpl1d, bremsstrahlung, brokenpowerlaw, ccm, const1d, const2d, cos, delta1d, delta2d, dered, devaucouleurs2d, disk2d, edge, emissiongaussian, emissionlorentz, emissionvoigt, erf, erfc, exp, exp10, fm, gauss1d, gauss2d, hubblereynolds, jdpileup, linebroad, list_model_components, list_models, lmc, load_xscflux, load_xsgsmooth, load_xsireflect, load_xskdblur, load_xskdblur2, load_xskerrconv, load_xslsmooth, load_xspartcov, load_xsrdblur, load_xsreflect, load_xssimpl, load_xszashift, load_xszmshift, log, log10, logabsorption, logemission, logparabola, lorentz1d, lorentz2d, models, normbeta1d, normgauss1d, normgauss2d, opticalgaussian, poisson, polynom1d, polynom2d, polynomial, powerlaw, powlaw1d, recombination, scale1d, scale2d, schechter, seaton, sersic2d, shell2d, sigmagauss2d, sin, sm, smc, sqrt, stephi1d, steplo1d, tablemodel, tan, xgal, xs, xsabsori, xsacisabs, xsagauss, xsapec, xsbapec, xsbbody, xsbbodyrad, xsbexrav, xsbexriv, xsbkn2pow, xsbknpower, xsbmc, xsbremss, xsbvapec, xsbvvapec, xsc6mekl, xsc6pmekl, xsc6pvmkl, xsc6vmekl, xscabs, xscemekl, xscevmkl, xscflow, xscompbb, xscompls, xscompmag, xscompps, xscompst, xscomptb, xscompth, xscomptt, xsconstant, xsconvolve, xscplinear, xscutoffpl, xscyclabs, xsdisk, xsdiskbb, xsdiskir, xsdiskline, xsdiskm, xsdisko, xsdiskpbb, xsdiskpn, xsdust, xsedge, xseplogpar, xseqpair, xseqtherm, xsequil, xsexpabs, xsexpdec, xsexpfac, xsezdiskbb, xsgabs, xsgadem, xsgaussian, xsgnei, xsgrad, xsgrbm, xsheilin, xshighecut, xshrefl, xskerrbb, xskerrd, xskerrdisk, xslaor, xslaor2, xslogpar, xslorentz, xslyman, xsmeka, xsmekal, xsmkcflow, xsnei, xsnotch, xsnpshock, xsnsa, xsnsagrav, xsnsatmos, xsnsmax, xsnsx, xsnteea, xsnthcomp, xsoptxagn, xsoptxagnf, xspcfabs, xspegpwrlw, xspexmon, xspexrav, xspexriv, xsphabs, xsplabs, xsplcabs, xsposm, xspowerlaw, xspshock, xspwab, xsraymond, xsredden, xsredge, xsrefsch, xsrnei, xssedov, xssirf, xssmedge, xsspexpcut, xsspline, xssrcut, xssresc, xssss_ice, xsstep, xsswind1, xstbabs, xstbgrain, xstbvarabs, xsuvred, xsvapec, xsvarabs, xsvbremss, xsvequil, xsvgadem, xsvgnei, xsvmcflow, xsvmeka, xsvmekal, xsvnei, xsvnpshock, xsvphabs, xsvpshock, xsvraymond, xsvrnei, xsvsedov, xsvvapec, xsvvgnei, xsvvnei, xsvvnpshock, xsvvpshock, xsvvrnei, xsvvsedov, xswabs, xswndabs, xsxion, xszagauss, xszbabs, xszbbody, xszbremss, xszdust, xszedge, xszgauss, xszhighect, xszigm, xszpcfabs, xszphabs, xszpowerlw, xszredden, xszsmdust, xsztbabs, xszvarabs, xszvfeabs, xszvphabs, xszwabs, xszwndabs, xszxipcf

Last modified: December 2015
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