Search Publications
Systematic X-Ray Analysis of Radio Relic Clusters with Suzaku
Akamatsu, Hiroki; Kawahara, Hajime
We undertook a systematic X-ray analysis of six giant radio relics in four clusters of galaxies using the Suzaku satellite. The sample included CIZA 2242.8+5301, Zwcl 2341.1-0000, the South-East part of A 3667 and previously published results of the North-West part of A 3667 and A 3376. Especially, we first observed the narrow (50 kpc) relic of CI…
K-Shell Line Distribution of Heavy Elements along the Galactic Plane Observed with Suzaku
Koyama, Katsuji; Nobukawa, Masayoshi; Tsuru, Takeshi Go +1 more
We report on the global distribution of the intensities of the K-shell lines from He-like and H-like ions of S, Ar, Ca, and Fe along the Galactic plane. From the profiles, we clearly separate the Galactic center X-ray emission (GCXE) and the Galactic ridge X-ray emission (GRXE). The intensity profiles of the He-like Kα lines of S, Ar, Ca, and Fe a…
X-Ray Echo from the Sagittarius C Complex and 500-year Activity History of Sagittarius A*
Koyama, Katsuji; Nobukawa, Masayoshi; Nakashima, Shinya +3 more
This paper presents Suzaku results obtained for the Sagittarius (Sgr) C region using the concept of X-ray reflection nebulae (XRNe) as the echo of past flares from a super-massive black hole, Sgr A*. The Sgr C complex is composed of several molecular clouds proximately located in projected distance. The X-ray spectra of Sgr C were analyzed based o…
Numerical Simulations of Solar Chromospheric Jets Associated with Emerging Flux
Shibata, Kazunari; Takasao, Shinsuke; Isobe, Hiroaki
We studied the acceleration mechanisms of chromospheric jets associated with emerging flux using a two-dimensional magnetohydrodynamic (MHD) simulation. We found that slow-mode shock waves generated by magnetic reconnection in the chromosphere and the photosphere play key roles in the acceleration mechanisms of chromospheric jets. An important par…
Evidence for a Cool Disk and Inhomogeneous Coronae from Wide-Band Temporal Spectroscopy of Cygnus X-1 with Suzaku
Done, Chris; Makishima, Kazuo; Yamada, Shin'ya +3 more
Unified X-ray spectral and timing studies of Cygnus X-1 in the low/hard and hard intermediate state were conducted in a model-independent manner, using broadband Suzaku data acquired on 25 occasions from 2005 to 2009 with a total exposure of ∼ 450 ks. The unabsorbed 0.1-500 keV source luminosity changed over 0.8%-2.8% of the Eddington limit for 14…
Low-Resolution Spectrum of the Extragalactic Background Light with the AKARI InfraRed Camera
Sakon, Itsuki; Matsuura, Shuji; Wada, Takehiko +2 more
The Extragalactic Background Light (EBL) as integrated light from outside of our Galaxy includes information about the early universe and the Dark Ages. We analyzed spectral data of the astrophysical diffuse emission obtained with the low-resolution spectroscopy mode on the AKARI Infra-Red Camera (IRC) in the
The Nature of Stable Soft X-Ray Emissions in Several Types of Active Galactic Nuclei Observed by Suzaku
Makishima, Kazuo; Nakazawa, Kazuhiro; Yamada, Shin'ya +3 more
To constrain the origin of the soft X-ray excess phenomenon seen in many active galactic nuclei, the intensity-correlated spectral analysis, developed by Noda et al. (2011, PASJ, 63, S925) for Markarian 509, was applied to wide-band (0.5-45 keV) Suzaku data of five representative objects with a relatively weak reflection signature. They are the ty…
Suzaku X-Ray Observations of the Accreting NGC 4839 Group of Galaxies and a Radio Relic in the Coma Cluster
Sarazin, Craig L.; Inoue, Susumu; Akamatsu, Hiroki +3 more
Based on Suzaku X-ray observations, we studied the hot gas around the NGC 4839 group of galaxies and a radio relic in the outskirts of the Coma cluster. We found a gradual decline in the gas temperature from 5 keV around NGC 4839 to 3.6 keV at the radio relic, across which there is a further, steeper drop down to 1.5 keV. This drop as well as the …
An X-Ray Detected Group of Quiescent Early-Type Galaxies at z = 1.6 in the Chandra Deep Field South
Brandt, William N.; Mulchaey, John S.; Ueda, Yoshihiro +6 more
We report the discovery of an X-ray group of galaxies located at a high redshift of
A Relation of the PAH 3.3 µm Feature with Star-forming Activity for Galaxies with a Wide Range of Infrared Luminosity
Oyabu, Shinki; Yamagishi, Mitsuyoshi; Im, Myungshin +4 more
For star-forming galaxies, we investigated a global relation between the polycyclic aromatic hydrocarbon (PAH) emission luminosity at 3.3 µm, LPAH3.3, and the infrared (8-1000 µm) luminosity, LIR, to understand how the PAH 3.3 µm feature relates to star-formation activity. With AKARI, we performed near-infra…