Search Publications
Observation of Very High Energy Gamma Rays from HESS J1804-216 with CANGAROO-III Telescopes
Katagiri, H.; Edwards, P. G.; Gunji, S. +46 more
We observed the unidentified TeV gamma-ray source HESS J1804-216 with the CANGAROO-III atmospheric Cerenkov telescopes from 2006 May to July. We detected very high energy gamma rays above 600 GeV at the 10 σ level in an effective exposure of 76 hr. We obtained a differential flux of (5.0 +/- 1.5stat+/- 1.6sys) × 10-12
Large-Scale Coronal Density and Abundance Structures and Their Association with Magnetic Field Structure
Raymond, John C.; Riley, Pete; Li, Jing +1 more
We construct subsynoptic maps of the ultraviolet-line fluxes, electron density, and elemental abundances for an east limb corona at 1.63 solar radii from 2000 September 20 to October 1. The data, covering position angles of 85°-126°, were taken from the Ultraviolet Coronagraph Spectrometer (UVCS) on board the Solar and Heliospheric Observatory (SO…
A Search for the Optical Counterpart to the Magnetar CXOU J010043.1-721134
van Kerkwijk, M. H.; Durant, M.
After our tentative detection of an optical counterpart to CXOU J010043.1-721134 from archival Hubble Space Telescope (HST) imaging, we have followed up with further images in four bands. Unfortunately, the source originally identified is not confirmed. We provide deep photometric limits in four bands and accurate photometry of field stars around …
An Overdensity of i-Dropouts among a Population of Excess Field Objects in the Virgo Cluster
Hathi, Nimish P.; Yan, Haojing; Windhorst, Rogier A.
Using a set of deep imaging data obtained by the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope (HST) shortly after its deployment, Yan, Windhorst, & Cohen found a large number of F775W-band dropouts (i-dropouts), which are consistent with being galaxies at z ≈ 6. The surface density of i-dropouts thus derived, however, is an …
XMM-Newton Observation of the Northeastern Limb of the Cygnus Loop
Tsunemi, Hiroshi; Miyata, Emi; Nemes, Norbert
In this paper we performed moderate-resolution spectroscopy on the data obtained with XMM-Newton of the northeastern limb of the Cygnus Loop. This observation was proposed as a higher resolution follow-up to that made by ASCA. We investigated the radial variation of the temperature, ionization timescale, elemental abundances, and hydrogen column d…
XMM-Newton Observation of the Cluster Zw 1305.4+2941 in the Field SA 57
Gastaldello, Fabio; Fusco-Femiano, Roberto; Vagnetti, Fausto +1 more
We report the details of an XMM-Newton observation of the cluster of galaxies Zw 1305.4+2941 at the intermediate redshift z = 0.241, increasing the small number of interesting X-ray constraints on properties of ~3 keV systems above z = 0.1. Based on the ~45 ks XMM-Newton observation, we find that within a radius of 228 kpc the cluster has an unabs…
Impact of Active Regions on Coronal Hole Outflows
Habbal, Shadia Rifai; McIntosh, Scott W.; Scholl, Isabelle F.
Establishing the sources of the fast and slow solar wind is important for understanding their drivers and their subsequent interaction in interplanetary space. Although coronal holes continue to be viewed as the main source of the fast solar wind, there is recent evidence that the quiet Sun provides other spatially concentrated sources. To identif…
Number Density Evolution of Ks-Band-Selected High-Redshift Galaxy Populations in the AKARI North Ecliptic Pole Field
Oyabu, Shinki; Matsuhara, Hideo; Takagi, Toshinobu +5 more
We present the number counts of Ks-band-selected high-redshift galaxy populations such as extremely red objects (EROs), B-, z-, and K-band-selected galaxies (BzKs) and distant red galaxies (DRGs) in the AKARI NEP field. These high-redshift galaxy samples are extracted from a multicolor catalog combining optical data from Suprime-Cam on …
First High Solar Phase Angle Observations of Rhea Using Cassini VIMS: Upper Limits on Water Vapor and Geologic Activity
Brown, R. H.; Buratti, B. J.; Nicholson, P. D. +5 more
Using radiances acquired with Cassini's Visual and Infrared Mapping Spectrometer (VIMS), we construct high solar phase angle curves for Saturn's second largest moon, Rhea. Ground-based studies of Rhea and Saturnian icy satellites are focussing on low phase angles; to our knowledge, these are the first solar phase curve data for Rhea on phase angle…
A Glimpse into the Past: The Recent Evolution of Globular Clusters
Anderson, Jay; Strader, Jay; Richer, Harvey B. +1 more
We present the serendipitous discovery of 195 extragalactic globular clusters (GCs) in one of the deepest optical images ever obtained, a 126 orbit Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) imaging study of the nearby Galactic GC NGC 6397. The distant GCs are all found surrounding a bright elliptical galaxy in the field and ar…