Search Publications
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 …
Atomic carbon [C I](3P1-3P0) mapping of the nearby galaxy M 83
Seta, Masumichi; Salak, Dragan; Nakai, Naomasa +6 more
Atomic carbon (C I) has been proposed to be a global tracer of the molecular gas as a substitute for CO, however, its utility remains unproven. To evaluate the suitability of C I as the tracer, we performed [C I](3P1-3P0) [hereinafter [C I](1-0)] mapping observations of the northern part of the nearby sp…
A fundamental plane in X-ray binary activity of external galaxies
Ueda, Yoshihiro; Inoue, Yoshiyuki; Yabe, Kiyoto
We construct a new catalog of extragalactic X-ray binaries (XRBs) by matching the latest Chandra source catalog with local galaxy catalogs. Our XRB catalog contains 4430 XRBs hosted by 237 galaxies within ~130 Mpc. As XRBs dominate the X-ray activity in galaxies, the catalog enables us to study the correlations between the total X-ray luminosity o…
The spatial structure and dynamical state of the open cluster NGC 2112
Gao, Xinhua; Xu, ShouKun; Xue, Lei
This paper investigates the spatial structure and dynamical state of the old open cluster NGC 2112 based on likely cluster members from Gaia Early Data Release 3. Using the Density-Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm, we find 1193 likely cluster members down to G ~ 21 mag within a radius of 1.°5 from the cluster …
The C18O core mass function toward Orion A: Single-dish observations
Sanhueza, Patricio; Kataoka, Akimasa; Nakamura, Fumitaka +6 more
We have performed an unbiased dense core survey toward the Orion A Giant Molecular Cloud in the C18O (J = 1-0) emission line taken with the Nobeyama Radio Observatory (NRO) 45 m telescope. The effective angular resolution of the map is 26″, which corresponds to ~0.05 pc at a distance of 414 pc. By using the Herschel-Planck H2…
New candidates for AM Canum Venaticorum stars among ASAS-SN transients
Kato, Taichi; Kojiguchi, Naoto
We studied Zwicky Transient Facility (ZTF) light curves of 34 dwarf nova candidates discovered by the All-Sky Automated Survey for Supernovae (ASAS-SN) between 2020 May 12 and September 9 and found six AM CVn-type candidates. All objects showed short outbursts (post-superoutburst rebrightenings) on the fading tail. Two objects (ASASSN-20eq, ASASSN…
Hyper Suprime-Cam Legacy Archive
Takita, Satoshi; Ikeda, Hiroyuki; Koike, Michitaro +5 more
We present the launch of the Hyper Suprime-Cam Legacy Archive (HSCLA), a public archive of processed, science-ready data from the Hyper Suprime-Cam (HSC). HSC is an optical wide-field imager installed at the prime focus of the Subaru Telescope and has been in operation since 2014. While ~1/3 of the total observing time of HSC has been used for the…
An intermediate-velocity H I cloud falling to the galactic disk; Possible evidence for low-metallicity H I gas originating outside the galactic disk
Tachihara, Kengo; Sasaki, Manami; Fukui, Yasuo +6 more
We found that an intermediate-velocity cloud (IVC), IVC 86-36, in H I 21 cm emission shows a head-tail distribution toward the Galactic plane with marked parallel filamentary streamers, which is extended over 40° in the sky. The distance of IVC 86-36 is constrained to be less than ∼3 kpc from absorption of a background star as determined from opti…
A study of the accretion mechanisms of the high-mass X-ray binary IGR J00370+6122
Fukazawa, Yasushi; Makishima, Kazuo; Takahashi, Hiromitsu +1 more
IGR J00370+6122 is a high-mass X-ray binary with a B1 Ib primary star and a companion suggested to be a neutron star because of the detection of a 346 s pulsation in a one-off 4 ks observation. To better understand the nature of the compact companion, the present work performs timing and spectral studies of the X-ray data of this object, taken wit…
First star survivors as metal-rich halo stars that experienced supernova explosions in binary systems
Matsuno, Tadafumi; Saitoh, Takayuki R.; Suda, Takuma +2 more
The search for the first stars formed from metal-free gas in the universe is one of the key issues in astronomy because it relates to many fields, such as the formation of stars and galaxies, the evolution of the universe, and the origin of elements. It is not still clear if metal-free first stars can be found in the present universe. These first …