Search Publications
On the diffuse X-ray emission from the Wolf-Rayet bubble NGC 2359
Gruendl, R. A.; Chu, Y. -H.; Guerrero, M. A. +1 more
A recent XMM-Newton observation has revealed diffuse X-ray emission inside the nebula NGC 2359 around the Wolf-Rayet star WR 7. Taking advantage of an improved point-source rejection and background subtraction, and a detailed comparison of optical and X-ray morphology, we have reanalysed these X-ray observations. Our analysis reveals diffuse X-ray…
Gemini Frontier Fields: Wide-field Adaptive Optics Ks-band Imaging of the Galaxy Clusters MACS J0416.1-2403 and Abell 2744
Schirmer, M.; Winge, C.; Neichel, B. +4 more
We have observed two of the six Frontier Fields galaxy clusters, MACS J0416.1-2403 and Abell 2744, using the Gemini Multi-Conjugate Adaptive Optics System (GeMS) and the Gemini South Adaptive Optics Imager (GSAOI). With 0.″ 08-0.″ 10 FWHM our data are nearly diffraction-limited over a 100\prime\prime × 100\prime\prime wide ar…
On the Possibility of Significant Electron Depletion due to Nanograin Charging in the Coma of Comet 67p/churyumov-gerasimenko near Perihelion
Wahlund, J. -E.; Vigren, E.; Galand, M. +2 more
We approach the complicated phenomena of gas-dust interactions in a cometary ionosphere, focusing in particular on the possibility of significant depletion in electron number density due to grain charging. Our one-dimensional ionospheric model, accounting for grain charging processes, is applied to the subsolar direction and the diamagnetic cavity…
The Chemical Composition of ρ Puppis and the Signs of Accretion in the Atmospheres of B-F-Type Stars
Lee, Byeong-Cheol; Kim, Sungeun; Lee, Jae-Woo +10 more
We investigated the chemical composition of ρ Pup using high-resolution spectral observations taken from the Very Large Telescope and the IUE archives and also spectra obtained at the 1.8 m telescope of the Bohyunsan observatory in Korea. The abundances of 56 chemical elements and the upper limits of Li and Be abundances were determined. The abund…
Acceleration of ions to suprathermal energies by turbulence in the plasmoid-like magnetic structures
Daly, P. W.; Malykhin, A. Yu.; Grigorenko, E. E. +2 more
We study energetic spectra of H+, He+, and O+ ion fluxes in the energy range ≥130 keV measured by Cluster/Research with Adaptive Particle Imaging Detectors (RAPID) instruments during 37 intervals of the tailward bulk flow propagation in the near-Earth tail (at X ≤ -19 RE). In all events from our database…
The evolution of disc galaxies with and without classical bulges since z ∼ 1
Sachdeva, Sonali; Saha, Kanak; Gadotti, Dimitri A. +1 more
Establishing relative role of internally and externally driven mechanisms responsible for disc and bulge growth is essential to understand the evolution of disc galaxies. In this context, we have studied the physical properties of disc galaxies without classical bulges in comparison to those with classical bulges since z ∼ 0.9. Using images from t…
Galaxy Formation at z > 3 Revealed by Narrowband-selected [O III] Emission Line Galaxies
Suzuki, Tomoko L.; Minowa, Yosuke; Koyama, Yusei +6 more
We present the physical properties of [O iii] emission line galaxies at z\gt 3 as the tracers of active galaxies at 1 Gyr before the peak epoch at z∼ 2. We have performed deep narrowband imaging surveys in the Subaru/XMM-Newton Deep Survey Field with the Multi-object InfraRed Camera and Spectrograph on the Subaru Telescope and have constructed coh…
The X-ray properties of weak-lensing-selected galaxy clusters
Birkinshaw, M.; Maughan, B. J.; Massey, R. +4 more
We present the results of an X-ray follow-up campaign targeting 10 weak-lensing (WL)-selected galaxy clusters from a Subaru WL survey. Archival Chandra data exist for two of the clusters, and we obtain dedicated observations of the remaining eight. The WL clusters appear to fit the same scaling relation between X-ray luminosity and temperature as …
Heavy-ion dominance near Cluster perigees
Kistler, L. M.; Zhang, J. -C.; Spence, H. E. +1 more
Time periods in which heavy ions dominate over H+ in the energy range of 1-40 keV were observed by the Cluster Ion Spectrometry (CIS)/COmposition DIstribution Function (CODIF) instrument onboard Cluster Spacecraft 4 at L values less than 4. The characteristic feature is a narrow flux peak at around 10 keV that extends into low L values,…
Global distribution of ionizing and recombining plasmas in the supernova remnant G290.1-0.8
Katsuda, Satoru; Koyama, Katsuji; Uchida, Hiroyuki +5 more
We report on the Suzaku results of the mixed-morphology supernova remnant (SNR) G290.1-0.8 (MSH 11-61A). The SNR has an asymmetric structure extended to the south-east and the north-west. In the X-ray spectra of the center and the north-west regions, we discover recombining plasma features with a strong Si Lyα and radiative recombination continuum…