Orbital and spin phase-resolved spectroscopy of the intermediate polar EX Hya using XMM-Newton data

Download

index.pdf

Date

2011-02-01

Author

Pekon, Y.
Balman, Şölen

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

140
views

48
downloads

We present the orbital phase-resolved spectra of an intermediate polar, EX Hya, together with the spin phase-resolved spectra during two different epochs using the X-ray Multi-Mirror Mission (XMM-Newton), European Photon Imaging Camera (pn instrument). We find that the source at the two epochs has the same X-ray luminosity of similar to 6.5 x 1031 erg s-1. We detect spectral variations between the 2000 and 2003 observations of the source. We fitted the spectrum using a neutral hydrogen absorption model with or without covering fraction together with Gaussians for emission lines, two collisional equilibrium plasma emission models (MEKAL) and a cooling-flow plasma emission model (VMCFLOW). We find that two of the three emission components (kT = 0.6-0.8 and 1.3-1.7 keV) fitted by the MEKAL models are almost constant over the spin and orbital phases and also over the two different epochs with the normalization varying directly proportional to the flux when the data are folded according to the orbital and spin phase indicating that the slight variation may be due to occultation. The emission modelled by the VMCFLOW changes over the spin and orbital phases and the 2000 and 2003 observations reveal two different ranges of temperatures (3-33 and 8-61 keV, respectively) that model the shock zone in the accretion column(s). The ratios of the spin maximum to minimum and the orbital maximum to minimum spectra along with the increase in the plasma temperatures indicate that the spectrum gets harder in the minimum phases of both orbital and spin periods. In the 2003 observation, a 6.4 keV fluorescent Fe emission line is present at the orbital minima in a range of phases from 0.9 to 1.3 and it is absent otherwise. This indicates that there is reflection from the disc most likely from a large bulge at the accretion impact zone.

Subject Keywords

Space and Planetary Science, Astronomy and Astrophysics

URI

https://hdl.handle.net/11511/56599

Journal

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY

DOI

https://doi.org/10.1111/j.1365-2966.2010.17752.x

Collections

Department of Physics, Article

Suggestions

OpenMETU
Core

ORBITAL-PHASE-RESOLVED SPECTROSCOPY OF THE INTERMEDIATE POLAR FO AQR USING XMM-NEWTON OBSERVATORY DATA Pekon, Y.; Balman, Şölen (IOP Publishing, 2012-08-01) We present the orbital-phase-resolved analysis of an archival FO Aqr observation obtained using the X-ray Multi-Mirror Mission, European Photon Imaging Camera (pn instrument). We investigate the variation of the spin pulse amplitudes over the orbital period in order to account for the effects of orbital motion on spin modulation. The semi-amplitude variations are in phase with the orbital modulation, changing from (38.0 +/- 1.8)% at the orbital maximum to (13.3 +/- 3.7)% at the orbital minimum. The spectral...
Optical imaging and spectroscopic observation of the galactic supernova remnant G85.9-0.6 GÖK, FATMA; Sezer, A.; Aktekin, E.; Guever, T.; Ercan, N. (Springer Science and Business Media LLC, 2009-11-01) Optical CCD imaging with H alpha and [SII] filters and spectroscopic observations of the galactic supernova remnant G85.9-0.6 have been performed for the first time. The CCD image data are taken with the 1.5 m Russian-Turkish Telescope (RTT150) at TBA degrees TAK National Observatory (TUG) and spectral data are taken with the Bok 2.3 m telescope on Kitt Peak, AZ.
Frequency-resolved spectroscopy of XB1323-619 using XMM-Newton data: detection of a reflection region in the disc Balman, Şölen (Oxford University Press (OUP), 2010-09-21) We present the frequency-resolved energy spectra (FRS) of the low-mass X-ray binary dipper XB1323-619 during persistent emission in four different frequency bands using an archival XMM-Newton observation. FRS method helps to probe the inner zones of an accretion disc. XB1323-619 is an Atoll source and a type-I burster. We find that the FRS is well described by a single blackbody component with kT in a range 1.0-1.4 keV responsible for the source variability in the frequency ranges of 0.002-0.04 and 0.07-0.3...
Upper limits to the SN1006 multi-TeV gamma-ray flux from HESS observations Aharonian, F; et. al. (EDP Sciences, 2005-07-01) Observations of the shell-type supernova remnant SN1006 have been carried out with the HESS system of Cherenkov telescopes during 2003 (18.2 h with two operating telescopes) and 2004 (6.3 h with all four telescopes). No evidence for TeV gamma-ray emission from any compact or extended region associated with the remnant is seen and resulting upper limits at the 99.9% confidence level are up to a factor 10 lower than previously-published fluxes from CANGAROO. For SN1006 at its current epoch of evolution we def...
The XMM-Newton detection of extended emission from the nova remnant of T Pyxidis Balman, Şölen (Oxford University Press (OUP), 2010-05-01) We report the detection of an extended X-ray nebulosity with an elongation from north-east to south-west in excess of 15 arcsec in a radial profile and imaging of the recurrent nova T Pyx using the archival data obtained with the X-ray Multi-Mirror Mission (XMM-Newton), European Photon Imaging Camera (pn instrument). The signal-to-noise ratio in the extended emission (above the point source and the background) is 5.2 over the 0.3-9.0 keV energy range and 4.9 over the 0.3-1.5 keV energy range. We calculate a...

Citation Formats

Y. Pekon and Ş. Balman, “Orbital and spin phase-resolved spectroscopy of the intermediate polar EX Hya using XMM-Newton data,” MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, pp. 1177–1196, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56599.