Search Publications
AKARI IRC Infrared 2.5-5 µm Spectroscopy of a Large Sample of Luminous Infrared Galaxies
Nakagawa, Takao; Shirahata, Mai; Imanishi, Masatoshi +2 more
We present the results of our systematic infrared 2.5-5 µm spectroscopy of 60 luminous infrared galaxies (LIRGs) with infrared luminosities L IR = 1011-1012 L sun and 54 ultraluminous infrared galaxies (ULIRGs) with L IR >= 1012 L sun, using the AKARI Infrared Ca…
Strengthening the Case for Asteroidal Accretion: Evidence for Subtle and Diverse Disks at White Dwarfs
Zuckerman, B.; Jura, M.; Farihi, J. +1 more
Spitzer Space Telescope IRAC 3-8 µm and AKARI IRC 2-4 µm photometry are reported for 10 white dwarfs with photospheric heavy elements; nine relatively cool stars with photospheric calcium and one hotter star with a peculiar high carbon abundance. A substantial infrared excess is detected at HE 2221-1630, while modest excess emissions a…
AKARI and BLAST Observations of the Cassiopeia A Supernova Remnant and Surrounding Interstellar Medium
Ade, P. A. R.; Bock, J. J.; Martin, P. G. +30 more
We use new large area far infrared maps ranging from 65 to 500 µm obtained with the AKARI and the Balloon-borne Large Aperture Submillimeter Telescope missions to characterize the dust emission toward the Cassiopeia A supernova remnant (SNR). Using the AKARI high-resolution data we find a new "tepid" dust grain population at a temperature of…
AKARI Observations of Brown Dwarfs. I. CO and CO2 Bands in the Near-infrared Spectra
Yamamura, Issei; Tanabé, Toshihiko; Tsuji, Takashi
Near-infrared medium-resolution spectra of seven bright brown dwarfs are presented. The spectra were obtained with the Infrared Camera on board the infrared astronomical satellite AKARI, covering 2.5-5.0 µm with a spectral resolution of approximately 120. The spectral types of the objects range from L5 to T8 and enable us to study the spectr…
A Tentative Identification of HCN Ice on Triton
Nakamura, R.; Burgdorf, M.; Cruikshank, D. P. +5 more
Spectra of Triton between 1.8 and 5.5 µm, obtained in 2007 May and 2009 November, have been analyzed to determine the global surface composition. The spectra were acquired with the grism and the prism of the Infrared Camera on board AKARI with spectral resolutions of 135 and 22, respectively. The data from 4 to 5 µm are shown in this L…
Enstatite-rich Warm Debris Dust Around HD165014
Nakagawa, Takao; Onaka, Takashi; Ootsubo, Takafumi +6 more
We present the Spitzer/Infrared Spectrograph spectrum of the main-sequence star HD165014, which is a warm (gsim200 K) debris disk candidate discovered by the AKARI All-Sky Survey. The star possesses extremely large excess emission at wavelengths longer than 5 µm. The detected flux densities at 10 and 20 µm are ~10 and ~30 times larger …
Detection of Parent H2O and CO2 Molecules in the 2.5-5 µm Spectrum of Comet C/2007 N3 (Lulin) Observed with AKARI
Nakagawa, Takao; Oyabu, Shinki; Hasegawa, Sunao +13 more
Comet C/2007 N3 (Lulin) was observed with the Japanese infrared satellite AKARI in the near-infrared at a post-perihelion heliocentric distance of 1.7 AU. Observations were performed with the spectroscopic (2.5-5.0 µm) and imaging (2.4, 3.2, and 4.1 µm) modes on 2009 March 30 and 31 UT, respectively. AKARI images of the comet exhibit a…
Ultra Deep Akari Observations of Abell 2218: Resolving the 15 µm Extragalactic Background Light
Smail, I.; Kneib, J. -P.; Im, M. +11 more
We present extragalactic number counts and a lower limit estimate for the cosmic infrared background (CIRB) at 15 µm from AKARI ultra deep mapping of the gravitational lensing cluster Abell 2218. These data are the deepest taken by any facility at this wavelength and uniquely sample the normal galaxy population. We have de-blended our source…
AKARI Near-infrared Spectroscopy of SDSS-selected Blue Early-type Galaxies
Matsuhara, Hideo; Lee, Myung Gyoon; Lee, Jong Chul +2 more
A near-infrared (NIR; 2.5-4.5 µm) spectroscopic survey of Sloan Digital Sky Survey (SDSS)-selected blue early-type galaxies (BEGs) has been conducted using the AKARI. The NIR spectra of 36 BEGs are secured, which are well balanced in their star formation (SF)/Seyfert/LINER-type composition. For high signal-to-noise ratio, we stack the BEG sp…
Observations of the Optical Transient in NGC 300 with AKARI/IRC: Possibilities of Asymmetric Dust Formation
Tanaka, M.; Matsuhara, H.; Nakagawa, T. +10 more
We present the results of near-infrared (NIR) multi-epoch observations of the optical transient in the nearby galaxy NGC 300 (NGC 300-OT) at 398 and 582 days after the discovery with the Infrared Camera (IRC) on board AKARI. NIR spectra (2-5 µm) of NGC 300-OT were obtained for the first time. They show no prominent emission nor absorption fe…