Search Publications
On the Extended Emission around the Anomalous X-Ray Pulsar 1E 1547.0-5408
Ng, C. -Y.; Zhu, W. W.; Kaspi, V. M. +4 more
We present an analysis of the extended emission around the anomalous X-ray pulsar 1E 1547.0-5408 using four XMM-Newton observations taken with the source in varying states of outburst as well as in quiescence. We find that the extended emission flux is highly variable and strongly correlated with the flux of the magnetar. Based on this result, as …
The X-Ray Properties of Typical High-redshift Radio-loud Quasars
Brandt, W. N.; Vignali, C.; Saez, C. +5 more
We report spectral, imaging, and variability results from four new XMM-Newton observations and two new Chandra observations of high-redshift (z >~ 4) radio-loud quasars (RLQs). Our targets span lower, and more representative, values of radio loudness than those of past samples of high-redshift RLQs studied in the X-ray regime. Our spectral anal…
Differential Morphology Between Rest-frame Optical and Ultraviolet Emission from 1.5 < z < 3 Star-forming Galaxies
Koekemoer, Anton M.; Gawiser, Eric; Bond, Nicholas A.
We present the results of a comparative study of the rest-frame optical and rest-frame ultraviolet morphological properties of 117 star-forming galaxies (SFGs), including BX, BzK, and Lyman break galaxies with B < 24.5, and 15 passive galaxies in the region covered by the Wide Field Camera 3 Early Release Science program. Using the internal col…
Herschel/HIFI Observations of IRC+10216: Water Vapor in the Inner Envelope of a Carbon-rich Asymptotic Giant Branch Star
Cernicharo, José; Szczerba, Ryszard; González-Alfonso, Eduardo +6 more
We report the results of observations of 10 rotational transitions of water vapor toward the carbon-rich asymptotic giant branch (AGB) star IRC+10216 (CW Leonis), carried out with Herschel's HIFI instrument. Each transition was securely detected by means of observations using the dual beam switch mode of HIFI. The measured line ratios imply that w…
AKARI Observations of Brown Dwarfs. II. CO2 as Probe of Carbon and Oxygen Abundances in Brown Dwarfs
Yamamura, Issei; Sorahana, Satoko; Tsuji, Takashi
Recent observations with the infrared astronomical satellite AKARI have shown that the CO2 bands at 4.2 µm in three brown dwarfs are much stronger than expected from the unified cloudy model (UCM) based on recent solar C & O abundances. This result has been a puzzle, but we now find it is simply due to the effect of C & O …
Suzaku Observations of the Prototype Wind-blown Bubble NGC 6888
Zhekov, Svetozar A.; Park, Sangwook
We present an analysis of the Suzaku observations of the prototype wind-blown bubble NGC 6888 which is based both on use of standard spectral models and on a direct comparison of theoretical models with observations. The X-ray spectra of NGC 6888 are soft and most of the X-rays are in the 0.3-1.5 keV energy range. But, hard X-rays (1.5-4.0 keV) ar…
Keck Spectroscopy of Lyman-break Galaxies and Its Implications for the UV-continuum and Lyα Luminosity Functions at z > 6
Ouchi, Masami; Shimasaku, Kazuhiro; Jiang, Linhua +6 more
We present Keck spectroscopic observations of z > 6 Lyman-break galaxy (LBG) candidates in the Subaru Deep Field (SDF). The candidates were selected as i'-dropout objects down to z' = 27 AB magnitudes from an ultra-deep SDF z'-band image. With the Keck spectroscopy we identified 19 LBGs with prominent Lyα emission lines at 6 <= z <= 6.4. …
Vector Magnetic Fields of A Solar Polar Region
Wang, Jingxiu; Jin, Chunlan
We study the vector magnetic fields of a solar polar region (PR) based on Solar Optical Telescope/Spectro-Polarimeter measurements. To better understand the polar magnetic properties, we compare the observed polar field with that in two solar quiet regions at the limb (QRL) and the disk center (QRD), and with that in a region of a low-latitude cor…
A Hubble Space Telescope/Cosmic Origins Spectrograph Search for Warm-hot Baryons in the Mrk 421 Sight Line
Shull, J. Michael; Danforth, Charles W.; Stocke, John T. +4 more
Thermally broadened Lyα absorbers (BLAs) offer an alternate method to using highly ionized metal absorbers (O VI, O VII, etc.) to probe the warm-hot intergalactic medium (WHIM, T = 105-107 K). Until now, WHIM surveys via BLAs have been no less ambiguous than those via far-UV and X-ray metal-ion probes. Detecting these weak, b…
Constraining Saturn's Core Properties by a Measurement of Its Moment of Inertia—Implications to the Cassini Solstice Mission
Helled, R.
Knowledge of Saturn's axial moment of inertia can provide valuable information on its internal structure. We suggest that Saturn's angular momentum may be determined by the Solstice Mission (Cassini XXM) by measuring Saturn's pole precession rate and the Lense-Thirring acceleration on the spacecraft, and therefore put constraints on Saturn's momen…