1 / 16

Tiziana Di Salvo DSFA Università di Palermo

Relativistic iron lines in neutron star X-ray Binaries : Probing strong gravity in neutron stars. Tiziana Di Salvo DSFA Università di Palermo. I n collaboration with : A. D'Aì , R. Iaria , N. R. Robba (Univ. Palermo) , L. Burderi (Univ. Cagliari ),

nodin
Download Presentation

Tiziana Di Salvo DSFA Università di Palermo

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. Relativisticironlines in neutron star • X-rayBinaries: Probing strong gravity in neutronstars Tiziana Di Salvo DSFA Universitàdi Palermo In collaboration with: • A. D'Aì, R. Iaria, N. R. Robba(Univ. Palermo), L. Burderi (Univ. Cagliari), • G. Matt (Univ. Roma Tre), M. Dovciak, V. Karas(Prague), et al.

  2. Ironlineprofilesmaygiveunvaluableinformation on the inneraccretion disc From the profileof a disc linewe can obtain information on the ionizationparameter and elementabundance, the emissivityindexof the disc, discinclinationwithrespectto the lineofsight, the inner and outerradiiof the emittingregion in the disc. This information maybeunaccessablewithotherobservationalmethods.

  3. High resolutionspectroscopyof massive BHs: MCG-6-30-15 XMM observationof the ironlineregion in MCG-6-30-15 taken in 2001. The redwingextendstolessthan4keV, indicatinganinnerradiusoflessthan 6GM / C2. Spinning blackhole? (a > 0.93) Fabianet al. (2002)

  4. High resolutionspectroscopyof BH X-raybinaries XTE J1650-500: Miniuttiet al. (2004) GX 339-4: Miller et al. (2004) Verybroadredwingsindicatinga rapidly spinning BH.

  5. High resolutionspectroscopyof NS Low Mass X-raybinaries Ser X-1 (XMM data): Bhattacharyya & Strohmayer(2007) Suzaku data: Cackettet al. (2008)

  6. High resolutionspectroscopyof NS Low Mass X-raybinarieswith XMM SAX J1808.4-3658 Papittoet al. (2009) Cackettet al. (2009) Patruno et al. (2009) GX 349+2 Iariaet al. (2009) GX 340+0 D’Aìet al. (2009)

  7. RelativisticIronLines in WDs? XMM-Newtonobservationof the CV GK Per Titarchuket al. 2009

  8. The source: 4U 1705-44 • 4U 1705-44: Atoll source and X-ray burster • It shows recurrent hard/low and soft/high states Pirainoet al. 2007

  9. Discoveryof a broad Fe K-shellLinein 4U 1705-44 during a soft state • Fitting the ironlineprofilewith a disk (relativistic) linewefind: • E_Fe = 6.40 keV • Rin = 7-11 Rg (15-23 km) • Inclination = 55 – 84 deg • Alternatively, Compton broadening in the externalpartsof the Comptonizing corona (s = 0.5 implies • t= 1.4 forkT = 2keV) TE Mode 25 ks Hintsof a double-peakedlineprofile Chandra/HETG observation Di Salvo et al. (2005)

  10. Dates of SUZAKU obs of 4U 1705-44 unpublished Reis et al. 2009

  11. ConfirmedbySuzaku Susaku/XIS observationof 4U 1705-44 Reiset al. (2009) Relativistic plus Compton broadeninggives: Rin = 10.5 Rg, i = 29.8 degrees

  12. The XMM spectrum of 4U 1705-44 • ToO observation performed in Aug 2008 during a soft state • 45 ks XMM-Newton exposure time • With800 c/s it is a high statistics spectrum ! Di Salvoet al. 2009 S XVI Ar XVIII Fe XXV Ca XIX

  13. The XMM-Newtonspectrumof 4U 1705-44 Residualswithrespectto the continuum model Di Salvo et al. (2009) The ironline at 6.7 keVis perfectlyfittedby a disklinewithverywelldeterminedparameters

  14. The relativisticlineof 4U 1705-44 F-testwithrespectto a simpleGaussianmodelgives a probof chance improvementof3x 10-11 ! EFe = 6.66 ± 0.01 keV Log x = 2.7 - 3 EqW = 56 ±2eV Rin = 14 ±2Rg i = 39 ±1degrees Emindex~ -2.2 Rout = 3500 ± 1000 Rg Di Salvo et al. (2009)

  15. Summary of the results on the other features Low energylinesfittedbydisklineswithparametersfixedto the correspondentvaluefor the ironline. The ironedgeappearssmaered and redshifted. More details on the fittingof the wholespectrumwith a self consistentreflectionmodel in the next talk by A. D’Aì Disc parameters

  16. See Di Salvo et al. 2009, MNRAS, 398, 2022 and D’Aìet al. 2010, submitted (next talk) for a more detaileddiscussionof the XMM-Newtonspectrumof 4U 1705-44 Thankyouverymuch!

More Related