CHANDRA AND RXTE OBSERVATIONS OF 1E 1547.0-5408: COMPARING THE 2008 AND 2009 OUTBURSTS

Ng C. -., Kaspi V. M., Dib R., Olausen S. A., Scholz P., Guever T., ...Daha Fazla

ASTROPHYSICAL JOURNAL, cilt.729, sa.2, 2011 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 729 Sayı: 2
  • Basım Tarihi: 2011
  • Doi Numarası: 10.1088/0004-637x/729/2/131
  • Dergi Adı: ASTROPHYSICAL JOURNAL
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: pulsars: individual (1E 1547.0-5408, PSR J1550-5418, SGR J1550-5418), stars: neutron, X-rays: bursts, X-RAY PULSAR, RESONANT CYCLOTRON SCATTERING, SPIN-DOWN, MAGNETAR, EMISSION, PERSISTENT, REPEATERS, SPECTRA, 1E-1547.0-5408, 1E-1048.1-5937
  • İstanbul Üniversitesi Adresli: Hayır

Özet

We present results from Chandra X-ray Observatory and Rossi X-ray Timing Explorer (RXTE) observations of the magnetar 1E 1547.0-5408 (SGR J1550-5418) following the source's outbursts in 2008 October and 2009 January. During the time span of the Chandra observations, which covers days 4 through 23 and days 2 through 16 after the 2008 and 2009 events, respectively, the source spectral shape remained stable in the Chandra band, while the pulsar's spin-down rate in the same span in 2008 increased by a factor of 2.2 as measured by RXTE. This suggests decoupling between the source's spin-down and radiative changes, hence between the spin-down-inferred magnetic field strength and that inferred spectrally. The lack of spectral variation during flux decay is surprising for models of magnetar outbursts. We also found a strong anti-correlation between the phase-averaged flux and the pulsed fraction in the 2008 and 2009 Chandra data, but not in the pre-2008 measurements. We discuss these results in the context of the magnetar model.