nlte model atmospheres for super-soft x- ray sources
DESCRIPTION
NLTE Model Atmospheres for Super-Soft X- ray Sources. Thomas Rauch, Klaus Werner and the GAVO and AstroGrid-D Teams. Spectral Energy Distributions for Hot Stars. The nebular information indicates that the spectrum of the star deviates considerably from a blackbody . Author in 2008!. - PowerPoint PPT PresentationTRANSCRIPT
NLTE Model AtmospheresNLTE Model Atmospheresfor Super-Soft X-ray for Super-Soft X-ray
SourcesSourcesThomas Rauch, Klaus
Wernerand the GAVO and AstroGrid-D Teams
www.g-vo.org
Spectral Energy Distributions for Hot Spectral Energy Distributions for Hot StarsStars
The nebular information indicates that the spectrum of the star deviates considerably
from a blackbody. Author in
2008!
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they still use black bodies to simulate ionizing fluxes of hot stars …
Rauch
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NLTE Model NLTE Model AtmospheresAtmospheres
• all stars with spectral type B or earlier
• regarded as a domain of specialists• high computational times• atomic data
C IV doublet
“optical” RBB 5 6, 6 8
C III singlet + triplet
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More Model Atoms …More Model Atoms …
simplified Hauschildt diagram
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and a very old gag ...and a very old gag ...
simplified Hauschildt diagram
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GAVO II ProjectGAVO II Project
• provide access to SEDs at three levels:
– fast and easy• unexperienced user, no detailed knowledge about
the model-atmosphere code necessary
– individual• interested user, detailed analysis of special
objects
– experienced• define own model atoms, comparison of codes,
etc.
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VO Service TheoSSAVO Service TheoSSA
• based on the Tübingen NLTE Model Atmosphere Package TMAP, the GAVO Service TheoSSA provides
– Spectral Energy Distributions (SEDs)• TheoSSA
(http://vo.ari.uni-heidelberg.de/ssatr-0.01/TrSpectra.jsp?)
– Simulation Software• TMAW (http://astro.uni-tuebingen.de/~TMAW/TMAW.shtml)
– Atomic Data• TMAD (http://astro.uni-tuebingen.de/~rauch/TMAD/TMAD.html)
www.g-vo.org
Way to Reality in the 21Way to Reality in the 21stst CenturyCentury
– use SED grids• ready to use, interpolation
– calculate individual model atmospheres • Teff, log g, mass fraction {Xi}, i (H, He, C, N,
O)– standard model atoms
– create own atomic-data files, i (H - Ni), and calculate model atmospheres and SEDs
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TheoSSA request: Teff, log g, {Xi}
check GAVO database:requested parameters matched
within tolerance limits?
yes: offer existing SEDno: calculate new model and SEDs
and ingest into GAVO database
accept request exact parameters
TheoSSA TheoSSA
IAAT databaseTeff, log g, {Xi}
modelsatomic data filefrequency grid
GAVO databaseTeff, log g, {Xi}
SEDs5 - 2000Å
2000 - 3000Å3000 - 55000Å
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Calculation of SEDs Calculation of SEDs
• cpu time increases with number of considered elements
– 1 H+He+C+N+O model ≈ 1 day on a fast PC
– IAAT cluster: 4 models parallel
• calculation of SED grids– compute resources of AstroGrid-D
www.g-vo.org
Why use a Grid?Why use a Grid?
• scales according to demand– 1, 10, or 100 cores available at any time
• higher reliability• middleware offers additional options
– job monitoring, statistics, error handling
• TMAP is easy to compute – no interprocess-communication– no complex compilation, all libraries
present
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Spectroscopy of LS V Spectroscopy of LS V +46°21+46°21
• exciting star of Sh 2-216– closest PN known, d = 130pc– apparent diameter 1.6°– LS V +46°21 about 0.2 radii off centre
• mild interaction with ISM• thin disk orbit of low inclination and eccentricity
– Kerber et al. 2004
• FUSE: 67.6 ksec in 2003/2004, R 0.05 Å• STIS: 5.5 ksec in 2000, R 0.06 Å
Hα + [O III] Dean Salman
www.deansalman.com
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Spectroscopy of LS V Spectroscopy of LS V +46°21+46°21
• HHeCNOFMgSiPSAr + CaScTiVCrMnFeCoNi– IrOnIc
• Rauch & Deetjen 2003
– 686 NLTE levels– 2417 individual lines– 9 million iron-group lines
• Kurucz 1996
• Rauch et al. 2007, A&A, 470, 317
TTeffeff = 95 000 K= 95 000 K log log gg = 6.9= 6.9
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LS V +46LS V +46°°2121
Photospheric abundances exhibit interplay of gravitational settling and radiative levitation
Photospheric abundancesin agreement with diffusion predictions (Chayer et al. 1995)
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Teff = 200 000 K log g = 8
H1504+65
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Magnesium in H Magnesium in H 1504+651504+65
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H H 1504+65: 1504+65: CHANDRA CHANDRA SpectrumSpectrum
Werner et al. 2004
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H 1504+65: Iron groupH 1504+65: Iron group
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Nova V 4743 SgrNova V 4743 Sgr
• outburst Sep 20, 2002, mV = 5
• Mar 2003: brightest super-soft source in the sky
• CHANDRA spectrum– C V, C VI, N VI, N VII, O VII absorptions
– Teff 1 – 2 MK (Ness et al. 2003)
• XMM-RGS spectrum (Apr 4, 2003)– Teff 610 kK (Rauch, Werner & Orio 2005)
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SEDs for Extremely Hot SEDs for Extremely Hot StarsStars
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V 4743 SgrV 4743 Sgr
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Teff Determination:
N VI / N VII Ionization
Equilibrium
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Effective Temperature of Nova V 4743 Sgr after Burst
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EXO 0748EXO 0748--676 (LMXB)676 (LMXB)
• discovery of gravitationally redshifted photosphericphotospheric absorption linesabsorption lines of
Fe XXV, Fe XXVI, O VIII in burst spectra
– Cottam, Paerels & Mendez 2002• letter to NATURE, 420, p. 51
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• no fit at z = 0.35
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• much better fit at z = 0.24 ?
• Details see Poster by Suleimanov et al. and Rauch et al. 2008
If carried out with sufficient care, theory works. D. Mihalas
Never believe an observation, until you have a theory to prove it.
L. Auer
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VO Service TheoSSAVO Service TheoSSA
– Spectral Energy Distributions (SEDs)• TheoSSA
(http://vo.ari.uni-heidelberg.de/ssatr-0.01/TrSpectra.jsp?)
– Simulation Software• TMAW
(http://astro.uni-tuebingen.de/~TMAW/TMAW.shtml)
– Atomic Data• TMAD
(http://astro.uni-tuebingen.de/~rauch/TMAD/TMAD.html)