Search Publications
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…
Modeling of the Extreme-Ultraviolet and Soft X-Ray Emission in a Solar Coronal Bright Point
Warren, Harry P.; Brooks, David H.
Previous studies have been able to reproduce both the observed intensities and the morphology of high-temperature solar plasma using steady state heating models. These models, however, have been unable to reproduce the lower temperature emission observed in active regions. Here we present results from numerical simulations of a coronal bright poin…
Secondary Photons from High-Energy Protons Accelerated in Hypernovae
Asano, Katsuaki; Mészáros, Peter
Recent observations show that hypernovae may deposit some fraction of their kinetic energy in mildly relativistic ejecta. In the dissipation process of such ejecta in a stellar wind, cosmic-ray protons can be accelerated up to ~1019 eV. We discuss the TeV to MeV gamma-ray and the X-ray photon signatures of cosmic rays accelerated in hyp…
High-Energy Properties of PKS 1830-211
Torres, Diego F.; Zhang, Shu; Wang, Jian-Min +4 more
We report an analysis of X-ray and γ-ray observations of PKS 1830-211, based on long-term campaigns carried out by INTEGRAL and COMPTEL. The INTEGRAL data currently available provide a 33 σ significance detection in the 20-100 keV band, while the COMPTEL 6 yr data provide a 5.2 σ significance detection in the 1-3 MeV energy band. In hard X-rays, I…
Line Intensity Ratios in the EIS Range Sensitive to Electron Densities in 107 K Plasmas
Landi, E.; Doschek, G. A.; Feldman, U.
Electron density variations during the rise, maximum, and decay phases of flaring plasmas at T simeq 10 MK are important quantities to be used to test flare models. To date, electron density values measured in solar flares are, with few exceptions, only lower limits. With the launch of the EUV Imaging Spectrometer (EIS) on Hinode, it has become po…