Search Publications
Comprehensive Broadband X-Ray and Multiwavelength Study of Active Galactic Nuclei in 57 Local Luminous and Ultraluminous Infrared Galaxies Observed with NuSTAR and/or Swift/BAT
Imanishi, Masatoshi; Tanimoto, Atsushi; Ueda, Yoshihiro +4 more
We perform a systematic X-ray spectroscopic analysis of 57 local luminous and ultraluminous infrared galaxy systems (containing 84 individual galaxies) observed with the Nuclear Spectroscopic Telescope Array and/or Swift/BAT. Combining soft X-ray data obtained with Chandra, XMM-Newton, Suzaku, and/or Swift/XRT, we identify 40 hard (>10 keV) X-r…
Discovery of 40.5 ks Hard X-Ray Pulse-phase Modulations from SGR 1900+14
Suzuki, H.; Enoto, T.; Makishima, K. +4 more
X-ray timing properties of the magnetar SGR 1900+14 were studied, using the data taken with Suzaku in 2009 and NuSTAR in 2016, for a time lapse of 114 and 242 ks, respectively. On both occasions, the object exhibited the characteristic two-component spectrum. The soft component, dominant in energies below ~5 keV, showed a regular pulsation, with a…
New measurements of the cyclotron line energy in Cen X-3
Paul, Biswajit; Pradhan, Pragati; Tomar, Gunjan
We report results from the analysis of data from two observations of the accreting binary X-ray pulsar Cen X-3 carried out with the broad-band X-ray observatories Suzaku and NuSTAR. The pulse profile is dominated by a broad single peak and show some energy dependence with two additional weak pulse peaks at energies below 15 and 25 keV, respectivel…
Long-term X-ray observations of seyfert 1 galaxy ark 120: on the origin of soft-excess
Chatterjee, Arka; Nandi, Prantik; Chakrabarti, Sandip K. +1 more
We present the long-term X-ray spectral and temporal analysis of a 'bare-type AGN' Ark 120. We consider the observations from XMM-Newton, Suzaku, Swift, and NuSTAR from 2003 to 2018. The spectral properties of this source are studied using various phenomenological and physical models present in the literature. We report (a) the variations of sever…
Joint Suzaku and Chandra observations of the MKW4 galaxy group out to the virial radius
Kraft, Ralph; Gastaldello, Fabio; Sarkar, Arnab +5 more
We present joint Suzaku and Chandra observations of MKW4. With a global temperature of 1.6 keV, MKW4 is one of the smallest galaxy groups that have been mapped in X-rays out to the virial radius. We measure its gas properties from its centre to the virial radius in the north, east, and north-east directions. Its entropy profile follows a power law…
A shock near the virial radius of the Perseus Cluster
Simionescu, A.; Kaastra, J. S.; Zhang, X. +6 more
Context. Previous X-ray studies of the Perseus Cluster, consisting of 85 Suzaku pointings along eight azimuthal directions, revealed a particularly steep decrease in the projected temperature profile near the virial radius (∼r200) towards the northwest (NW).
Aims: To further explore this shock candidate, another 4 Suzaku observatio…
Application of a new X-ray reflection model to V1223 Sagittarii
Ishida, Manabu; Hayashi, Takayuki; Kitaguchi, Takao
In intermediate polars (IPs), the intrinsic thermal emissions from white dwarfs (WDs) have typically been studied. Few reports have analysed X-ray reflections from WDs. We recently developed an elaborate IP-reflection spectral model. Herein, we report the first application of a reflection model with an IP thermal model to the spectra of the bright…
Detection of the hard X-ray non-thermal emission from Kepler's supernova remnant
Katsuda, Satoru; Terada, Yukikatsu; Bamba, Aya +1 more
We report the first robust detection of the hard X-ray emission in the 15-30 keV band from Kepler's supernova remnant with the silicon PIN-type semiconductor detector of the hard X-ray detector (HXD-PIN) onboard Suzaku. The detection significance is 7.17σ for the emission from Kepler's entire X-ray emitting region. The energy spectrum is found to …
Comprehensive broad-band study of accreting neutron stars with Suzaku: Is there a bi-modality in the X-ray spectrum?
Maitra, Chandreyee; Paul, Biswajit; Pradhan, Pragati +2 more
We present a broad-band spectral analysis of accreting neutron stars using data from XIS and PIN onboard Suzaku. From spectral fits of these sources with a single continuum model including a power law and high energy cut-off, cyclotron lines (where required), we studied the correlation between various spectral parameters. Among 39 sources we studi…
Are Compton-thin AGNs Globally Compton Thin?
Yukita, M.; Ptak, A.; LaMassa, S. +2 more
We select eight nearby active galactic nuclei (AGNs) which, based on previous work, appear to be Compton-thin in the line of sight. We model with MYTORUS their broadband X-ray spectra from 20 individual observations with Suzaku, accounting self-consistently for Fe Kα line emission, as well as direct and scattered continuum from matter with finite …