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Spectral behaviour of the M7 like NS RX J0720.4-3125 PowerPoint Presentation
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Spectral behaviour of the M7 like NS RX J0720.4-3125

Spectral behaviour of the M7 like NS RX J0720.4-3125

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Spectral behaviour of the M7 like NS RX J0720.4-3125

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  1. Spectral behaviour of the M7 like NS RX J0720.4-3125 Markus Hohle Astrophysikalisches Institut und Universitäts-Sternwarte, Jena & Max-Planck-Institut für extraterrestrische Physik, Garching Summer School, Dubna, July 2008

  2. What are the M7? • radio quiet • isolated • young • nearby “Magnificent Seven” Motch et al. (2006)

  3. RX J0720 distance : 360 pc kT : 86-95 eV X ray period : P=8.3911s, =0.698 (Kaplan & Kerkwijk et al., 2005/07) cyc p+ (?) line : 301 eV B field : 2.4 or 5.6 G line EW, kT, radius long term period: p=(7.1 +/- 0.5) yr (Haberl et al. 2006, Haberl 2007)

  4. 25 0078 0533 0534 0815 20 0986 1060 1086 15 1181 1265 cts/s 1356 1454 10 5 0 -0.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 log (energy [keV]) 10 spectral parameters Observations in ff & thin filter (11 of 14 tot) May 2000 – Nov 2007 abs. feature

  5. spectral parameters EPIC-pn, 2006 EPIC-pn ff thin, 2008

  6. timing residuals phase residualsperiod : (7.7 +/- 0.6) yr consistent with that derived from former spectral analysesHaberl (2007), Kaplan & Kerkweijk (2005)120-1200eV

  7. precession phase residualsperiod: (7.7 +/- 0.6) yr spectral variations period: (7.1 +/- 0.5) yr

  8. - two hot spots and precession - small hot spot: ~1000 days - period: ~2*2000 days = 2*5.5 yr - consistent with period from phase residuals ! precession

  9. timing residuals hard : 400-1000 eV soft : 120-400 eV using timing solution from Kaplan & Kerkwijk (2005) two hot spots: switch of phase lag

  10. abs(sine) Kaplan & Kerkwijk (2005) (10.694 +/- 0.058)yr abs(sine) Kaplan & Kerkwijk (2005) + linear (11.504 +/- 0.072)yr abs(sine) Kerkwijk et al. (2007) + linear (10.530 +/- 0.069)yr

  11. timing residuals

  12. timing solution -hardness changes -phase lag between hard and soft photons requires energy dependent timing solution still precessing?

  13. 40 0078 20 0533 0534 0 -20 EW [eV] -40 -60 1454 -80 -100 84 86 88 90 92 94 96 98 100 kT [eV] precession vs glitch • dipolar magnetic field -> hot spots Haberl et al. (2006) & de Vries et al. (2004) • -> precession (RBS 1223) Schwope et al. (2005) ->grav. waves • no companion found Posselt et al. (2008, submitted) • ISM • Hohle et al. (will be submitted after Dubna)

  14. Thank you very much! RX J2143 RX J0720 RX J1605 RX J0806 RX J1308 RX J0420 RX J1856