Search Publications
AKARI Observations of Circumstellar Dust in the Globular Clusters NGC 104 and NGC 362
Ohyama, Y.; Matsunaga, N.; Takagi, T. +19 more
We report on preliminary results of AKARI observations of two globular clusters, NGC 104 and NGC 362. Imaging data covering areas of about 10 F_{7} ratio being greater than unity in NGC 362. Six out of the eight have no 2MASS counterparts. However, we found no such source in NGC 104.
A NewModel for the Structure of the DACs and SACs Regions in the Oe and Be Stellar Atmospheres
Antoniou, A.; Danezis, E.; Lyratzi, E. +4 more
In this paper we present a new mathematical model for the density regions where a specific spectral line and its SACs/DACs are created in the Oe and Be stellar atmospheres. In the calculations of final spectral line function we consider that the main reasons of the line broadening are the rotation of the density regions creating the spectral line …
Wavelength Determination for Solar Features Observed by the EUV Imaging Spectrometer on Hinode
Doschek, George A.; Hara, Hirohisa; Culhane, Len +10 more
A wavelength calibration of solar lines observed by the high resolution EUV Imaging Spectrometer (EIS) on the Hinode satellite is reported. Spectral features of the quiet sun and of two mildly active areas were measured and calibrated. A listing of the stronger observed lines with identification of the leading contributor ions is presented. 41 lin…
Diagnostics of Radio Fine Structures around 3 GHz with Hinode Data in the Impulsive Phase of an X3.4/4B Flare Event on 2006 December 13
Chen, Bin; Sakurai, Takashi; Yan, Yihua +1 more
On 2006 December 13 during the solar minimum, the superactive region NOAA 10930 at the S05W33 disk location produced an X3.4/4B flare at 02:40UT. Fine structures were observed in the radio spectra, which included spikes, reverse slope-type III bursts, type-U burst, V-shaped burst, pulsations, zebra patterns, and firstly discovered sub-second spiky…
Chandra Detections of Diffuse X-Ray Emission from Globular Clusters
Kokubun, Motohide; Makishima, Kazuo; Yuasa, Takayuki +1 more
Using Chandra, extended X-ray emission was detected from the direction of 6 globular clusters: 47 Tucanae, NGC 6752, M 5, ω Centauri, M 80, and NGC 6266. These X-ray sources, extending to a few arcmin, are located 1'--6' away from the cluster centers, and some are found in the direction of cluster motion through the Galactic halo. All of these sou…
AKARI Infrared Imaging of Reflection Nebulae IC4954 and IC4955
Ohyama, Y.; Takagi, T.; Matsuhara, H. +26 more
We present the observations of the reflection nebulae IC4954 and IC4955 region with the Infrared Camera and the Far-Infrared Surveyor (FIS) on board the infrared astronomical satellite AKARI during its performance verification phase. We obtained 7 band images from 7 to 1601° around the IC4954/4955 region was created from the AKARI mid-infrared All…
Observations of Transient Active Region Heating with Hinode
Warren, Harry P.; Hara, Hirohisa; Ugarte-Urra, Ignacio +3 more
We present observations of transient active region heating events observed with the Extreme Ultraviolet Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on Hinode. This initial investigation focuses on NOAA active region 10940 as observed by Hinode on 2007 February 1 between 12 and 19UT. In these observations we find numerous examples of trans…
Search for Oxygen Emission from Warm-Hot Intergalactic Medium around A2218 with Suzaku
Kelley, Richard L.; Hughes, John P.; Ohashi, Takaya +12 more
We searched for redshifted O emission lines from a possible warm-hot intergalactic medium (WHIM) surrounding the cluster of galaxies A2218 at z=0.1756 using the X-ray Imaging Spectrometer (XIS) instrument on Suzaku. This cluster is thought to have an elongated structure along the line of sight based on previous studies. We studied systematic uncer…
Hinode EUV Imaging Spectrometer Observations of Solar Active Region Dynamics
Warren, Harry P.; Hara, Hirohisa; Ugarte-Urra, Ignacio +3 more
The EUV Imaging Spectrometer (EIS) on the Hinode satellite is capable of measuring emission line center positions for Gaussian line profiles to a fraction of a spectral pixel, resulting in relative solar Doppler-shift measurements with an accuracy of a less than a km s-1 for strong lines. We show an example of the application of that ca…
The Structure and Dynamics of the Quiet Corona from Observations with the Extreme Ultraviolet Imaging Spectrometer on Hinode
Harra, Louise K.; Doschek, George A.; Hansteen, Viggo H. +4 more
The goal of the Hinode mission is to provide an observational basis for understanding the heating and acceleration of coronal plasmas. On 2007 January 20, the Extreme ultraviolet Imaging Spectrometer performed a raster of a quiet region near Sun center. Maps of intensities, velocities, and electron densities derived from these observations are pre…