An X-Ray Spectral Fitting Package
Users' Guide for version 12.14.1
Keith Arnaud, Craig Gordon, Ben Dorman & Kristin Rutkowski
HEASARC
Astrophysics Science Division
NASA/GSFC
Greenbelt, MD 20771
August 2024
- Contents
- Introduction
- Spectral Fitting and XSPEC
- XSPEC Overview and Helpful Hints
- Walks through XSPEC
- XSPEC Commands
- XSPEC Models
- Alphabetical Summary of Models
- Additive Model Components
- agauss, zagauss: gaussian line profile in wavelength
space
- agnsed, qsosed: AGN SED model
- agnslim, AGN super-Eddington accretion model
- apec, vapec, vvapec, bapec, bvapec, bvvapec: APEC emission spectrum
- atable: tabulated additive model
- bbody, zbbody: blackbody
- bbodyrad: blackbody spectrum, area normalized
- bexrav: reflected e-folded broken power law, neutral
medium
- bexriv: reflected e-folded broken power law, ionized medium
- bkn2pow: broken power law, 2 break energies
- bknpower, zbknpower: broken power law
- bmc: Comptonization by relativistic matter
- bremss, vbremss, zbremss: thermal bremsstrahlung
- btapec, bvtapec, bvvtapec: velocity broadened APEC
emission spectrum with separate continuum and line temperatures
- bwcycl: Becker-Wolff self-consistent cyclotron line model
- c6mekl, c6vmekl, c6pmekl, c6pvmkl: differential emission
measure using Chebyshev representations with multi-temperature
mekal
- carbatm: Nonmagnetic carbon atmosphere of a neutron star
- cemekl, cevmkl: plasma emission, multi-temperature using mekal
- cempow, vcempow, bcempow, bvcempow: plasma emission,
multi-temperature using a power-law emission measure
- cflow: cooling flow
- cheb6, vcheb6, bcheb6, bvcheb6: differential emission
measure using 6-order Chebyshev polynomial
- cie, vcie, vvcie, bcie, bvcie, bbvcie:
Emission spectrum from a plasma in Collisional-ionization equilibrium
- compbb: Comptonization, black body
- compLS: Comptonization, Lamb & Sanford
- compmag: Thermal and bulk Comptonization for cylindrical
accretion onto the polar cap of a magnetized neutron star
- compPS: Comptonization, Poutanen & Svensson
- compST: Comptonization, Sunyaev &
Titarchuk
- comptb: Thermal and bulk Comptonization of a seed blackbody-like spectrum
- compTT: Comptonization, Titarchuk
- coolflow, vcoolflow, bcoolflow, bvcoolflow: cooling flow, mekal
- cph, vcph, bcph, bvcph: Cooling + heating model for cool core clusters
- cplinear: a non-physical piecewise-linear model for low count
background spectra.
- cutoffpl, zcutoffpl: power law, high energy exponential cutoff
- disk: accretion disk, black body
- diskbb: accretion disk, multi-black body components
- diskir: Irradiated inner and outer disk
- diskline: accretion disk line emission, relativistic
- diskm: accretion disk with gas pressure viscosity
- disko: accretion disk, inner, radiation pressure viscosity
- diskpbb: accretion disk, power-law dependence for T(r)
- diskpn: accretion disk, black hole, black body
- eebremss: electron-electron bremsstrahlung spectrum
- eplogpar: log-parabolic blazar model with F normalization
- Eqpair, eqtherm, compth: Paolo Coppi's hybrid (thermal/non-thermal) hot plasma emission models.
- equil, vequil, bequil, bvequil: collisional plasma, ionization equilibrium
- expcheb6, vexpcheb6, bexpcheb6, bvexpcheb6: differential emission
measure using exponential of a 6-order Chebyshev polynomial
- expdec: exponential decay
- ezdiskbb: multiple blackbody disk model with zero-torque
inner boundary
- gadem, vgadem, vvgadem, bgadem, bvgadem, bvvgadem: plasma emission, multi-temperature with
gaussian distribution of emission
measure.
- gauss, zgauss: gaussian line profile
- gnei, vgnei, vvgnei, bgnei, bvgnei, bvvgnei: collisional plasma, non-equilibrium, temperature evolution
- grad: accretion disk, Schwarzschild black hole
- grbcomp: Comptonization for GRB prompt emission
- grbjet: Two-phase Comptonization model of soft thermal
seed photons for GRB prompt emission
- grbm: gamma-ray burst continuum
- hatm: Nonmagnetic hydrogen atmosphere of a neutron star
- jet: Leptonic relativistic jet model
- kerrbb, zkerrbb: multi-temperature blackbody model for thin accretion disk around a Kerr black hole
- kerrd: optically thick accretion disk around a Kerr black hole
- kerrdisk: accretion disk line emission with BH spin as free parameter
- kyrline: relativistic line from axisymmetric accretion disk
- laor: accretion disk, black hole emission line
- laor2: accretion disk with broken-power law emissivity profile, black hole emission line
- logpar, zlogpar: log-parabolic blazar model
- lorentz: lorentz line profile
- meka, vmeka: emission, hot diffuse gas
(Mewe-Gronenschild)
- mekal, vmekal: emission, hot diffuse gas
(Mewe-Gronenschild-Kaastra)
- mkcflow, vmcflow: cooling flow, mekal
- nei, vnei, vvnei, bnei, bvnei, bvvnei: collisional plasma, non-equilibrium,
constant temperature
- nlapec: continuum-only APEC emission spectrum
- npshock, vnpshock, vvnpshock, bnpshock, bvnpshock, bvvnpshock: shocked plasma, plane
parallel, separate ion, electron temperatures
- nsa: neutron star atmosphere
- nsagrav: NS H atmosphere model for different g
- nsatmos: NS Hydrogen Atmosphere model with electron conduction and self-irradiation
- nsmax: Neutron Star Magnetic Atmosphere
- nsmaxg: Neutron Star with a Magnetic Atmosphere
- nsx: neutron star with a non-magnetic atmosphere
- nteea: non-thermal pair plasma
- Nthcomp: Thermally comptonized continuum
- Optxagnf, optxagn: Colour temperature corrected disc and energetically coupled Comptonisation model for AGN.
- pegpwrlw: power law, pegged normalization
- pexmon: neutral Compton reflection with self-consistent Fe and Ni lines.
- pexrav: reflected powerlaw, neutral medium
- pexriv: reflected powerlaw, ionized medium
- plcabs: powerlaw observed through dense, cold matter
- polconst: Constant polarization
- pollin: Linearly dependent polarization
- polpow: Power-law dependent polarization
- posm: positronium continuum
- powerlaw, zpowerlw: power law photon spectrum
- pshock, vpshock, vvpshock, bpshock, bvpshock, bvvpshock: plane-parallel shocked plasma, constant temperature
- raymond, vraymond: emission, hot diffuse gas, Raymond-Smith
- redge: emission, recombination edge
- refsch: reflected power law from ionized accretion disk
- relline, relline_lp, relline_lp_ext: relativistic accretion disk
line emission with different geometries
- rnei, vrnei, vvrnei, brnei, bvrnei, bvvrnei: non-equilibrium recombining
collisional plasma
- sedov, vsedov, vvsedov, bsedov, bvsedov, bvvsedov: sedov model, separate ion, electron
temperatures
- sirf: self-irradiated funnel
- slimbh: Stationary slim accretion disk
- smaug: optically-thin, spherically-symmetric thermal plasma.
- snapec, bsnapec: galaxy cluster spectrum using SN yields
- srcut: synchrotron spectrum, cutoff power law
- sresc: synchrotron spectrum, cut off by particle escape
- ssa: Strangeon star atmosphere
- sssed: Shakura & Sunyaev spectral energy distribution
- step: step function convolved with gaussian
- tapec, vtapec, vvtapec: APEC emission spectrum with
separate continuum and line temperatures
- wdem, vwdem, vvwdem, bwdem, bwwdem, bvvwdem: plasma emission, multi-temperature with
power-law distribution of emission measure.
- vagauss, zvagauss: gaussian line profile in wavelength
space with sigma in velocity
- vgauss, zvgauss: gaussian line profile with sigma in velocity
- voigt: Voigt line profile
- Multiplicative Model Components
- absori: ionized absorber
- acisabs: Chandra ACIS q.e. decay
- cabs: Optically-thin Compton scattering.
- constant: energy-independent factor
- cyclabs: absorption line, cyclotron
- dust: dust scattering
- edge, zedge: absorption edge
- etable: exponential tabular model
- expabs: exponential roll-off at low E
- expfac: exponential modification
- gabs, zgabs: gaussian absorption line
- heilin: Voigt absorption profiles for He I series
- highecut, zhighect: high-energy cutoff
- hrefl: reflection model
- ismabs: A high resolution ISM absorption model with variable columns for individual ions
- ismdust: Extinction due to a power-law distribution of
dust grains
- logconst: Constant in log units
- log10con: Constant in base 10 log units
- lyman: Voigt absorption profiles for H I or He II Lyman series
- mtable: multiplicative tabular model
- notch: absorption line, notch
- olivineabs: Absorption due to olivine.
- pcfabs, zpcfabs: partial covering fraction absorption
- phabs, vphabs, zphabs, zvphabs: photoelectric absorption
- plabs: power law absorption
- pwab: power-law distribution of neutral absorbers
- redden: interstellar extinction
- smedge: smeared edge
- spexpcut: super-exponential cutoff absorption
- spline: spline modification
- SSSice: Einstein SSS ice absorption
- swind1: absorption by partially ionized material with large velocity shear
- tbabs, ztbabs, tbfeo, tbgas, tbgrain, tbpcf, tbvarabs, tbrel: ISM grain absorption
- uvred: interstellar extinction, Seaton Law
- varabs, zvarabs: photoelectric absorption
- vgabs, zvgabs: gaussian absorption line with sigma in km/s
- wabs, zwabs: photoelectric absorption, Wisconsin cross-sections
- wndabs, zwndabs: photo-electric absorption, warm absorber
- xion: reflected spectrum of photo-ionized accretion disk/ring
- xscat: dust scattering
- zbabs: EUV ISM attenuation
- zdust: extinction by dust grains
- zigm: UV/Optical attenuation by the intergalactic medium
- zredden: redshifted version of redden
- zsmdust: extinction by dust grains in starburst galaxies
- zvfeabs: photoelectric absorption with free Fe edge energy
- zxipab: power-law distribution of ionized absorbers
- zxipcf: partial covering absorption by partially ionized material
- Convolution Model Components
- Pile-Up Model Components
- Mixing Model Components
- Appendix A: The User Interface
- Appendix B: Statistics in XSPEC
- Appendix C: Adding Models to XSPEC
- Appendix D: Overview of PLT
- Appendix E: Associated Programs
- Appendix F: Using the XSPEC Models Library in Other Programs
- Appendix G: Adding a Custom Chain Proposal Algorithm
- Appendix H: Changes between v11 and v12
- Appendix I: Older Release Notes
- Appendix J: Glossary
- About this document ...
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Last modified: Friday, 23-Aug-2024 13:20:40 EDT
HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.
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