1 / 32

NLTE Model Atmospheres for Super-Soft X- ray Sources

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!.

cutter
Download Presentation

NLTE Model Atmospheres for Super-Soft X- ray Sources

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. NLTE Model Atmospheresfor Super-Soft X-raySources Thomas Rauch, Klaus Werner and the GAVO and AstroGrid-D Teams

  2. Spectral Energy Distributions for Hot Stars The nebularinformationindicatesthatthespectrumofthestardeviatesconsiderablyfrom a blackbody. Author in 2008!

  3. they still use black bodies to simulate ionizing fluxes of hot stars … Rauch

  4. NLTE Model Atmospheres C IV doublet “optical” RBB 5  6, 6  8 C III singlet + triplet all stars with spectral type B or earlier regarded as a domain of specialists high computational times atomic data

  5. More Model Atoms … simplified Hauschildt diagram

  6. and a very old gag ... simplified Hauschildt diagram

  7. GAVO 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.

  8. VO 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)

  9. Way to Reality in the 21st Century • 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

  10. TheoSSA

  11. Calculationof 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

  12. 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

  13. Spectroscopy of LS V +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

  14. Spectroscopy of LS V +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 Teff= 95 000 K log g = 6.9

  15. LS V +46°21 Photospheric abundances exhibit interplay of gravitational settling and radiative levitation Photospheric abundances in agreement with diffusion predictions (Chayer et al. 1995)

  16. H1504+65 Teff = 200 000 K log g = 8

  17. Magnesium in H 1504+65

  18. H 1504+65: CHANDRA Spectrum Werner et al. 2004

  19. H 1504+65: Iron group

  20. Nova 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)

  21. SEDs for Extremely Hot Stars

  22. V 4743 Sgr

  23. Teff Determination: N VI / N VII IonizationEquilibrium

  24. Effective Temperature of Nova V 4743 Sgr after Burst

  25. EXO 0748-676 (LMXB) • discovery of gravitationally redshifted photosphericabsorption lines of Fe XXV, Fe XXVI, O VIII in burst spectra • Cottam, Paerels & Mendez 2002 • letter to NATURE, 420, p. 51

  26. no fit at z = 0.35

  27. much better fit at z = 0.24 ? • Details see Poster by Suleimanov et al. and Rauch et al. 2008

  28. If carried out with sufficient care, theory works. D. Mihalas Never believe an observation, until you have a theory to prove it. L. Auer

  29. VO 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)

More Related