Search Publications
Investigating the relation between CO (3-2) and far-infrared luminosities for nearby merging galaxies using ASTE
Kaneko, Hiroyuki; Muto, Takayuki; Ueda, Junko +10 more
We present the new single-dish CO (3-2) emission data obtained toward 19 early-stage and 7 late-stage nearby merging galaxies using the Atacama Submillimeter Telescope Experiment (ASTE). Combining with the single-dish and interferometric data of galaxies observed in previous studies, we investigate the relation between the CO (3-2) luminosity (L^'…
New identification of the mixed-morphology supernova remnant G298.6-0.0 with possible gamma-ray association
Petre, Robert; Terada, Yukikatsu; Bamba, Aya +4 more
We present an X-ray analysis on the Galactic supernova remnant (SNR) G298.6-0.0 observed with Suzaku. The X-ray image shows a center-filled structure inside a radio shell, implying that this SNR can be categorized as a mixed-morphology (MM) SNR. The spectrum is well reproduced by a single-temperature plasma model in ionization equilibrium, with a …
Mid- and far-infrared properties of Spitzer Galactic bubbles revealed by the AKARI all-sky surveys
Yamagishi, Mitsuyoshi; Kaneda, Hidehiro; Fukui, Yasuo +9 more
We have carried out a statistical study on the mid- and far-infrared (IR) properties of Galactic IR bubbles observed by Spitzer. Using the Spitzer 8 µm images, we estimated the radii and covering fractions of their shells, and categorized them into closed, broken, and unclassified bubbles with our data analysis method. Then, using the AKARI …
SXDF-ALMA 2 arcmin2 deep survey: Resolving and characterizing the infrared extragalactic background light down to 0.5 mJy
Tamura, Yoichi; Kohno, Kotaro; Yun, Min S. +22 more
We present a multiwavelength analysis of five submillimeter sources (S1.1mm = 0.54-2.02 mJy) that were detected during our 1.1 mm deep continuum survey in the Subaru/XMM-Newton Deep Survey Field (SXDF)-UDS-CANDELS field (2 arcmin2, 1σ = 0.055 mJy beam-1) using the Atacama Large Millimeter/submillimeter Array (ALMA)…
Recombining plasma in the remnant of a core-collapsed supernova, Kes 17
Koyama, Katsuji; Uchida, Hiroyuki; Nobukawa, Masayoshi +4 more
We report on Suzaku results concerning Kes 17, a Galactic mixed-morphology supernova remnant. The X-ray spectrum of the whole Kes 17 is well explained by a pure thermal plasma, in which we found Lyα of Al XIII and Heα of Al XII, Ar XVII, and Ca XIX lines for the first time. The abundance pattern and the plasma mass suggest that Kes 17 is a remnant…
Revised wavelength and spectral response calibrations for AKARI near-infrared grism spectroscopy: Cryogenic phase
Nakagawa, Takao; Baba, Shunsuke; Isobe, Naoki +6 more
We perform revised spectral calibrations for the AKARI near-infrared grism to correct quantitatively for the effect of the wavelength-dependent refractive index. The near-infrared grism covering the wavelength range of 2.5-5.0 µm, with a spectral resolving power of 120 at 3.6 µm, is found to be contaminated by second-order light at wav…
Suzaku study on the ejecta of the supernova remnant G272.2-3.2
Katsuda, Satoru; Koyama, Katsuji; Uchida, Hiroyuki +5 more
We report reanalyses of the Suzaku observations of the Galactic supernova remnant (SNR) G272.2-3.2, for which previous studies were limited below 3 keV. With careful data reduction and background subtraction, we discover the K-shell lines of Ar, Ca, and Fe above 3 keV. The X-ray spectrum of G272.2-3.2 consists of two components, a low-temperature …
Suzaku observations of a shock front tracing the western edge of the giant radio halo in the Coma Cluster
Allen, Steven W.; Takahashi, Tadayuki; Ichinohe, Yuto +5 more
We present the results of new Suzaku observations of the Coma Cluster, the X-ray brightest, nearby, merging system hosting a well-studied, typical giant radio halo. It has been previously shown that, on the western side of the cluster, the radio brightness shows a much steeper gradient compared to other azimuths. XMM-Newton and Planck revealed a s…
Search for a non-equilibrium plasma in the merging galaxy cluster Abell 754
Koyama, Katsuji; Hayashida, Kiyoshi; Tsunemi, Hiroshi +3 more
Abell 754 is a galaxy cluster in which an ongoing merger is evident on the plane of the sky, from the southeast to the northwest. We study the spatial variation of the X-ray spectra observed with Suzaku along the merging direction, centering on the Fe Ly α/Fe He α line ratio to search for possible deviation from ionization equilibrium. Fitting wit…
Origin of the characteristic X-ray spectral variations of IRAS 13224-3809
Ebisawa, Ken; Mizumoto, Misaki; Sameshima, Hiroaki +1 more
The narrow-line Seyfert 1 galaxy (NLS1) IRAS 13224-3809 is known to exhibit significant X-ray spectral variation, a sharp spectral drop at ∼7 keV, strong soft excess emission, and a hint of an iron L-edge feature, which is very similar to the NLS1 1H 0707-495. We have proposed the "Variable Double Partial Covering (VDPC) model" to explain the ener…