Search Publications
2MASS 22344161+4041387AB: A Wide, Young, Accreting, Low-Mass Binary in the LkHα233 Group
Shkolnik, Evgenya; Cushing, Michael C.; Dupuy, Trent J. +6 more
We report the discovery of a young, 0farcs16 binary, 2M2234+4041AB, found as the result of a Keck laser guide star adaptive optics imaging survey of young field ultracool dwarfs. Spatially resolved near-infrared photometry and spectroscopy indicate that the luminosity and temperature ratios of the system are near unity. From optical and near-infra…
Local Twist and Current Helicity Distributions of Active Region NOAA 10930
Liu, Yu; Su, J. T.; Suematsu, Y. +2 more
Hinode high-quality vector magnetograms and G-band data are utilized to study the distributions of local twist α z and current helicity hc on the active region of NOAA 10930. The new findings are as follows. (1) The patches of positive and negative helicities were intermixed showing a mesh pattern in the umbra and a thread p…
Detection of Ne VIII in an Intervening Multiphase Absorption System Toward 3C 263
Savage, Blair D.; Wakker, Bart P.; Narayanan, Anand
We report the detection of Ne VIII in an intervening multiphase absorption line system at z = 0.32566 in the Far Ultraviolet Spectroscopic Explorer spectrum of the quasar 3C 263 (zem = 0.646). The Ne VIII λ770 Å detection has a 3.9σ significance. At the same velocity, we also find absorption lines from C IV, O III, O IV, and N IV. The l…
Evolution of Physical Characteristics of Umbral Dots and Penumbral Grains
Jurčák, J.; Sobotka, M.
A time series of full-Stokes spectropolarimetric observations of the sunspot NOAA 10944, acquired with HINODE/SOT in 2007 February, is analyzed. The data were inverted using the code SIR into a series of 34 maps covering 3 hr of umbra and penumbra evolution. The retrieved maps of plasma parameters show the spatial distribution of temperature, line…
A Search for Iron Emission Lines in the Chandra X-Ray Spectra of Neutron Star Low-Mass X-Ray Binaries
Wijnands, R.; Miller, J. M.; Homan, J. +6 more
While iron emission lines are well studied in black hole systems, both in X-ray binaries and active galactic nuclei, there has been less of a focus on these lines in neutron star low-mass X-ray binaries (LMXBs). However, recent observations with Suzaku and XMM-Newton have revealed broad, asymmetric iron line profiles in three neutron star LMXBs, c…
Spitzer Observations of The H II Region NGC 2467: An Analysis of Triggered Star Formation
Bally, John; Hester, J. Jeff; Desch, Steven J. +2 more
We present new Spitzer Space Telescope observations of the region NGC 2467, and use these observations to determine how the environment of an H II region affects the process of star formation. Our observations comprise IRAC (3.6, 4.5, 5.8, and 8.0 µm) and MIPS (24 µm) maps of the region, covering approximately 400 arcmin2. T…
Characteristic Dependence of Umbral Dots on Their Magnetic Structure
Ichimoto, K.; Kitai, R.; Watanabe, H.
Umbral dots (UDs) were observed in a stable sunspot in NOAA 10944 by the Hinode Solar Optical Telescope on 2007 March 1. The observation program consisted of blue continuum images and spectropolarimetric profiles of Fe I 630 nm line. An automatic detection algorithm for UDs was applied to the 2 hr continuous blue continuum images, and using the ob…
Disentangling the Circumnuclear Environs of Centaurus A. I. High-Resolution Molecular Gas Imaging
Iono, D.; Espada, D.; Petitpas, G. +8 more
We present high-resolution images of the 12CO(2-1) emission in the central 1' (1 kpc) of NGC 5128 (Centaurus A), observed using the Submillimeter Array. We elucidate for the first time the distribution and kinematics of the molecular gas in this region with a resolution of 6farcs0 × 2farcs4 (100 pc × 40 pc). We spatially resolve the cir…
A Wide-Field Study of the z ~ 0.8 Cluster RX J0152.7-1357: The Role of Environment in the Formation of the Red Sequence
Franx, Marijn; Kelson, Daniel D.; Illingworth, Garth D. +4 more
We present the first results from the largest spectroscopic survey to date of an intermediate redshift galaxy cluster, the z = 0.834 cluster RX J0152.7-1357. We use the colors of galaxies, assembled from a D ~ 12 Mpc region centered on the cluster, to investigate the properties of the red sequence as a function of density and clustercentric radius…
Dissecting the Region of 3EG J1837-0423 and HESS J1841-055 with INTEGRAL
Masetti, N.; Bird, A. J.; Bassani, L. +3 more
3EG J1837-0423 and HESS J1841-055 are two unidentified and peculiar high-energy sources located in the same region of the sky, separated by ~1.4°. Specifically, 3EG J1837-0423 is a transient MeV object detected by EGRET only once during flaring activity that lasted a few days while HESS J1841-055 is a highly extended TeV source. We attempted to ma…