Search Publications
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…
A Comparison of Methods for Determining the Age Distribution of Star Clusters: Application to the Large Magellanic Cloud
Whitmore, Bradley C.; Fall, S. Michael; Chandar, Rupali
The age distribution of star clusters in nearby galaxies plays a crucial role in evaluating the lifetimes and disruption mechanisms of the clusters. Two very different results have been recently found for the age distribution χ(τ) of clusters in the Large Magellanic Cloud (LMC). We found that χ(τ) can be approximately described by a power law χ(τ)…
On the Isothermality of Solar Plasmas
Klimchuk, J. A.; Landi, E.
Recent measurements have shown that the quiet unstructured solar corona observed at the solar limb is close to isothermal, at a temperature that does not appear to change over wide areas or with time. Some individual active region loop structures have also been found to be nearly isothermal both along their axis and across their cross section. Eve…
Suzaku X-ray Spectra and Pulse Profile Variations During the Superorbital Cycle of LMC X-4
Vrtilek, Saeqa D.; Hickox, Ryan C.; Hung, Li-Wei +1 more
We present results from spectral and temporal analyses of Suzaku and RXTE observations of the high-mass X-ray binary LMC X-4. Using the full 13 years of available RXTE/all-sky monitor data, we apply the ANOVA and Lomb Normalized Periodogram methods to obtain an improved superorbital period measurement of 30.32 ± 0.04 days. The phase-averaged X-ray…
Warm Coronal Rain on Young Solar Analog EK Draconis?
France, Kevin; Ayres, Thomas
We report a moderate-resolution, 1290-1430 Å spectrum of young solar analog EK Draconis (HD 129333: G1.5 V), obtained by Cosmic Origins Spectrograph on Hubble Space Telescope. The 20 minute observation, remarkably, captured two distinct "flares" in the Si IV 1400 Å doublet (T ~ 6 × 104 K); very broad profiles of Si IV and the C II 1335 …
Golden Gravitational Lensing Systems from the Sloan Lens ACS Survey. I. SDSS J1538+5817: One Lens for Two Sources
Grillo, C.; Lombardi, M.; Gobat, R. +4 more
We present a gravitational lensing and photometric study of the exceptional strong lensing system SDSS J1538+5817, identified by the Sloan Lens Advanced Camera for Survey. The lens is a luminous elliptical galaxy at redshift zl = 0.143. Using Hubble Space Telescope public images obtained with two different filters, the presence of two b…
Suzaku Observation of the Brightest Broad-line Radio Galaxy 4C 50.55 (IGR J21247+5058)
Isobe, Naoki; Ueda, Yoshihiro; Terashima, Yuichi +4 more
We report the results from a deep Suzaku observation of 4C 50.55 (IGR J21247+5058), the brightest broad-line radio galaxy in the hard X-ray (>10 keV) sky. The simultaneous broadband spectra over 1-60 keV can be represented by a cutoff power law with two layers of absorption and a significant reflection component from cold matter with a solid an…
Evidence for Convection in Sunspot Penumbrae
Solanki, S. K.; Bharti, L.; Hirzberger, J.
We present an analysis of twisting motions in penumbral filaments in sunspots located at heliocentric angles from 30° to 48° using three time series of blue continuum images obtained by the Broadband Filter Imager (BFI) on board Hinode. The relations of the twisting motions to the filament brightness and the position within the filament and within…
A Far-infrared Characterization of 24 µm Selected Galaxies at 0 < z < 2.5 using Stacking at 70 µm and 160 µm in the COSMOS Field
Kartaltepe, Jeyhan S.; Sanders, D. B.; Frayer, D. T. +7 more
We present a study of the average properties of luminous infrared galaxies detected directly at 24 µm in the COSMOS field using a median stacking analysis at 70 µm and 160 µm. Over 35,000 sources spanning 0 <= z <= 3 and 0.06 mJy <=S 24 <= 3.0 mJy are stacked, divided into bins of both photometric redshift …
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…