Search Publications
Temporal and spectral X-ray properties of magnetar SGR 1900+14 derived from observations with NuSTAR and XMM-Newton
Enoto, Teruaki; Bamba, Aya; Odaka, Hirokazu +1 more
X-ray observations play a crucial role in understanding the emission mechanism and relevant physical phenomena of magnetars. We report on X-ray observations made in 2016 of a young magnetar, SGR 1900+14, which is famous for a giant flare in 1998 August. Simultaneous observations were conducted with XMM-Newton and NuSTAR on 2016 October 20 with 23 …
Searches for Population III pair-instability supernovae: Impact of gravitational lensing magnification
Oguri, Masamune; Koyama, Yusei; Nomoto, Ken'ichi +3 more
Superluminous supernovae have been proposed to arise from Population III progenitors that explode as pair-instability supernovae (PISNe). Population III stars are the first generation of stars in the Universe, and are thought to have formed as late as z ∼ 6. Future near-infrared imaging facilities such as ULTIMATE-Subaru will potentially be able t…
Discovery of a strong ionized-gas outflow in an AKARI-selected ultra-luminous infrared galaxy at z = 0.5
Yamamura, Issei; Noda, Hirofumi; Kokubo, Mitsuru +5 more
In order to construct a sample of ultra-luminous infrared galaxies (ULIRGs; with infrared luminosity LIR > 1012 L_{⊙}) at 0.5 < z < 1, we are conducting an optical follow-up program for bright 90 µm far-infrared sources with a faint optical (i < 20 mag) counterpart selected in the AKARI Far-Infrared Surveyor…
AKARI NEP field: Point source catalogs from GALEX and Herschel observations and selection of candidate lensed sub-millimeter galaxies
Goto, Tomotsugu; Burgarella, Denis; Pearson, Chris +9 more
The AKARI Wide North Ecliptic field is one of the most important cosmological fields because it lies in the continuous viewing zones for many space telescopes, e.g., Herschel, HST, and JWST, and it is also a natural high-visibility field from the L2 halo orbit. The field will be also the location of the deep survey for the Euclid mission. Finally,…
Solar jet-like features rooted in flare ribbons
Hou, Yijun; Yang, Shuhong; Zhang, Jun +1 more
Employing the high spatio-temporal Interface Region Imaging Spectrograph 1330 Å observations, we investigated the jet-like features that occurred during the X8.2 class flare in NOAA active region (AR) 12673 on 2017 September 10. These jet-like features were rooted in the flare ribbons. We examined 15 features, and the mean values of the lifetimes,…
Large angular scale fluctuations of near-infrared extragalactic background light based on the IRTS observations
Jeong, Woong-Seob; Lee, Hyung Mok; Tanaka, Masahiro +4 more
We measure the spatial fluctuations of the Near-Infrared Extragalactic Background Light (NIREBL) from 2° to 20° in angular scale at the 1.6 and 2.2 µ m using data obtained with Near-Infrared Spectrometer (NIRS) on board the Infrared Telescope in Space (IRTS). The brightness of the NIREBL is estimated by subtracting foreground components such…
Ionization age of iron ejecta in the Galactic Type Ia supernova remnant G306.3-0.9
Uchida, Hiroyuki; Bamba, Aya; Tsuru, Takeshi Go +5 more
We present a 190 ks observation of the Galactic supernova remnant (SNR) G306.3-0.9 with Suzaku. To study ejecta properties of this possible Type Ia SNR, the absolute energy-scale at the Fe-K band was calibrated to a level of uncertainty less than 10 eV by a cross-calibration with the Hitomi microcalorimeter using the Perseus cluster spectra. This …
Radio-infrared correlation for local dusty galaxies and dusty AGNs from the AKARI All-Sky Survey
Pollo, Agnieszka; Bilicki, Maciej; Takeuchi, Tsutomu T. +3 more
We use the new release of the AKARI Far-Infrared All-Sky Survey (FIS) matched with the NVSS radio database to investigate the local (z < 0.25) far-infrared-radio correlation (FIRC) of different types of extragalactic sources. To obtain the redshift information for the AKARI FIS sources we cross-match the catalogue with the SDSS DR8. This also a…
Star formation and polycyclic aromatic hydrocarbons in ELAIS N1 galaxies as seen by AKARI
Burgarella, Denis; Oyabu, Shinki; Kaneda, Hidehiro +4 more
We have examined the relationship between star formation and polycyclic aromatic hydrocarbons (PAHs) in a variety of galaxies. PAHs are excited by the ultraviolet photons of young stars, but they are disassociated by strong UV radiation in starbursts. Therefore their emission (which is in the wavelength range covered by AKARI) can be used as a sta…
NSV 1440: first WZ Sge-type object in AM CVn stars and candidates
Nogami, Daisaku; Myers, Gordon; Monard, Berto +5 more
In 2015 and 2017, the AM CVn candidate NSV 1440 showed superoutbursts that had the characteristic features of WZ Sge-type dwarf novae (DNe). By analogy with hydrogen-rich cataclysmic variables (CVs), we can interpret these outbursts as "double superoutbursts" which are composed of a first superoutburst with early superhumps and a second superoutbu…