Search Publications
The Temperature Distribution of Horizontal Branch Stars: Methods and First Results
Dalessandro, E.; Salaris, M.; Lagioia, E. P. +4 more
As part of a large project aimed at characterizing the ultraviolet (UV) properties of globular clusters, we present here a theoretical and observational analysis aimed at setting the framework for the determination of horizontal branch (HB) temperature distributions. Indeed this is crucial information needed to understand the physical parameters s…
The Unification of Powerful Quasars and Radio Galaxies and Their Relation to Other Massive Galaxies
Haas, Martin; Barthel, Peter; Wilkes, Belinda +2 more
The unification model for powerful radio galaxies (RGs) and radio-loud quasars postulates that these objects are intrinsically the same but viewed along different angles. Herschel Space Observatory data permit the assessment of that model in the far-infrared spectral window. We analyze photometry from Spitzer and Herschel for the distant 3CR hosts…
Variable Hard-X-Ray Emission from the Candidate Accreting Black Hole in Dwarf Galaxy Henize 2-10
Greene, Jenny E.; Johnson, Kelsey E.; Goulding, Andy D. +5 more
We present an analysis of the X-ray spectrum and long-term variability of the nearby dwarf starburst galaxy Henize 2-10. Recent observations suggest that this galaxy hosts an actively accreting black hole (BH) with mass ∼106 {{M}⊙ }. The presence of an active galactic nucleus (AGN) in a low-mass starburst galaxy marks a new e…
A Compact High Velocity Cloud near the Magellanic Stream: Metallicity and Small-scale Structure
Kumari, Nimisha; Fox, Andrew J.; Tumlinson, Jason +3 more
The Magellanic Stream (MS) is a well-resolved gaseous tail originating from the Magellanic Clouds. Studies of its physical properties and chemical composition are needed to understand its role in Galactic evolution. We investigate the properties of a compact HVC (CHVC 224.0-83.4-197) lying close on the sky to the MS to determine whether it is phys…
Multi-wavelength Observations of the Black Widow Pulsar 2FGL J2339.6-0532 with OISTER and Suzaku
Nogami, Daisaku; Matsunaga, Noriyuki; Yoshida, Michitoshi +42 more
Multi-wavelength observations of the black widow binary system 2FGL J2339.6-0532 are reported. The Fermi gamma-ray source 2FGL J2339.6-0532 was recently categorized as a black widow in which a recycled millisecond pulsar (MSP) is evaporating the companion star with its powerful pulsar wind. Our optical observations show clear sinusoidal light curv…
Photospheric Flow Field Related to the Evolution of the Sun's Polar Magnetic Patches Observed by Hinode Solar Optical Telescope
Kubo, M.; Tsuneta, S.; Suematsu, Y. +3 more
We investigated the role of photospheric plasma motions in the formation and evolution of polar magnetic patches using time-sequence observations with high spatial resolution. The observations were obtained with the spectropolarimeter on board the Hinode satellite. From the statistical analysis using 75 magnetic patches, we found that they are sur…
The Q/U Imaging Experiment: Polarization Measurements of Radio Sources at 43 and 95 GHz
Dickinson, C.; Eriksen, H. K.; Huffenberger, K. M. +24 more
We present polarization measurements of extragalactic radio sources observed during the cosmic microwave background polarization survey of the Q/U Imaging Experiment (QUIET), operating at 43 GHz (Q-band) and 95 GHz (W-band). We examine sources selected at 20 GHz from the public, >40 mJy catalog of the Australia Telescope (AT20G) survey. There a…
Observational Evidence for the Causes and Consequences of Chromospheric Reconnection
He, Jiansen; Xia, Lidong; Jiao, Fangran +1 more
The chromospheric anemone jets with an inverse “Y” shape are ubiquitous, as revealed by the Solar Optical Telescope observations. These jets are considered to be consequences of chromospheric magnetic reconnections. Although these jets have been studied intensively, the dynamics and their driving causes remain unclear observationally. In this work…
An Analytical Model of Interplanetary Coronal Mass Ejection Interactions
Lara, A.; Cantó, J.; González, R. F. +1 more
We present an analytical model that describes the evolution of two consecutive interplanetary coronal mass ejections (ICMEs), their interaction, and the evolution of the merged region. In this model, the coronal mass ejections (CMEs) are seen as velocity and density (mass loss rate) fluctuations of the solar wind that result in the formation of sh…
Suzaku Observations of Subhalos in the Coma Cluster
Sato, Kosuke; Okabe, Nobuhiro; Matsushita, Kyoko +1 more
We observed three massive subhalos in the Coma cluster with Suzaku. These subhalos, labeled “ID 1,” “ID 2,” and “ID 32,” were detected with a weak-lensing survey using Subaru/Suprime-Cam, and are located at the projected distances of 1.4 r500, 1.2 r500, and 1.6 r500 from the center of the Coma cluster, respectively…