Search Publications
Multi-epoch X-ray spectral analysis of the narrow-line Seyfert 1 galaxy Mrk 478
Gallo, L. C.; Zoghbi, A.; Gonzalez, A. G. +2 more
A multi-epoch X-ray spectral and variability analysis is conducted for the narrow-line Seyfert 1 (NLS1) active galactic nucleus (AGN) Mrk 478. All available X-ray data from XMM-Newton and Suzaku satellites, spanning from 2001 to 2017, are modelled with a variety of physical models, including partial covering, soft Comptonization, and blurred refle…
The nature of the soft excess and spectral variability in the Seyfert 1 galaxy Zw 229.015
Welsh, W. F.; Gallo, L. C.; Waddell, S. G. H. +2 more
We have carried out a systematic analysis of the nearby (z = 0.0279) active galaxy Zw 229.015 using multi-epoch, multi-instrument, and deep pointed observations with XMM-Newton, Suzaku, Swift,and NuSTAR. Spectral and temporal variability are examined in detail on both the long (weeks-to-years) and short (hours) time-scales. A deep Suzaku observati…
Long-term soft and hard X-ray investigation of the colliding wind WN+O binary WR 25
Pandey, J. C.; De Becker, M.; Arora, Bharti
We investigated the long-term behaviour in X-rays of the colliding wind binary WR 25, using archival data obtained with Suzaku, Swift, XMM-Newton, and NuSTAR spanning over ∼16 yr. Our analysis reveals phase-locked variations repeating consistently over many consecutive orbits, in agreement with an X-ray emission fully explained by thermal emission…
Discovery of recombining plasma inside the extended gamma-ray supernova remnant HB9
Fukui, Y.; Sano, H.; Sezer, A. +2 more
We present the results from the Suzaku X-ray Imaging Spectrometer observation of the mixed-morphology supernova remnant (SNR) HB9 (G160.9+2.6). We discovered recombining plasma (RP) in the western Suzaku observation region and the spectra here are well described by a model having collisional ionization equilibrium (CIE) and RP components. On the o…
Investigating the origin of the Fe emission lines of the Seyfert 1 galaxy Mrk 205
Guainazzi, Matteo; Laha, Sibasish; Tripathi, Shruti +1 more
We have investigated the nature and origin of the Fe K emission lines in Mrk 205 using observations with Suzaku and XMM-Newton, aiming to resolve the ambiguity between a broad emission line and multiple unresolved lines of higher ionization. We detect the presence of a narrow Fe K α emission line along with a broad-band Compton reflection hump at …
A new possible accretion scenario for ultra-luminous X-ray sources
Makishima, K.; Nakazawa, K.; Kobayashi, Shogo B.
Using archival data from Suzaku, XMM-Newton, and NuSTAR, nine representative ultra-luminous X-ray sources (ULXs) in nearby galaxies were studied. Their X-ray spectra were all reproduced with a multicolour disc emission model plus its Comptonization. However, the spectral shapes of individual sources changed systematically depending on the luminosi…
Variation of mass accretion rate on to the white dwarf in the dwarf nova VW Hyi in quiescence
Ishida, Manabu; Hayashi, Takayuki; Nakaniwa, Nozomi +1 more
We have analysed a series of Suzaku data and one data set of XMM-Newton of the SU UMa type dwarf nova VW Hyi in optical quiescence. The observed spectra in the 0.2-10 keV band are moderately well represented by multitemperature thermal plasma emission models with a maximum temperature of 5-9 keV and bolometric luminosity of (2.4-5.2) × 1030
Ionization state of the accretion disc in the neutron star low-mass X-ray binary 4U 1728-34
Méndez, Mariano; Xiang, Fu-Yuan; Lyu, Ming +1 more
We analysed an XMM-Newton plus a simultaneous Rossi X-ray Timing Explorer observation and a separate Suzaku observation of the neutron star low-mass X-ray binary 4U 1728-34. We fitted the X-ray spectra with the self-consistent reflection model RELXILL. We found that the inclination angle of 4U 1728-34 is 49 ± 5 degree, consistent with the upper li…
Explaining the asymmetric line profile in Cepheus X-4 with spectral variation across pulse phase
Fürst, Felix; Pottschmidt, Katja; Ballhausen, Ralf +4 more
The high mass X-ray binary Cepheus X-4, during its 2014 outburst, showed evidence for an asymmetric cyclotron line in its hard X-ray spectrum. The 2014 spectrum provides one of the clearest cases of an asymmetric line profile among all studied sources with Cyclotron Resonance Scattering Features (CRSF). We present a phase-resolved analysis of NuST…