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Comet C/2011 W3 (Lovejoy): Orbit Determination, Outbursts, Disintegration of Nucleus, Dust-tail Morphology, and Relationship to New Cluster of Bright Sungrazers
Sekanina, Zdenek; Chodas, Paul W.
We describe the physical and orbital properties of C/2011 W3. After surviving perihelion passage, the comet was observed to undergo major physical changes. The permanent loss of the nuclear condensation and the formation of a narrow spine tail were observed first at Malargue, Argentina, on December 20 and then systematically at Siding Spring, Aust…
X-ray observations of the galaxy cluster Abell 2029 to the virial radius
Fabian, A. C.; Sanders, J. S.; Walker, S. A. +2 more
We present Suzaku observations of the galaxy cluster Abell 2029, which exploit Suzaku's low particle background to probe the intracluster medium at radii beyond that which is possible with previous observations, and with better azimuthal coverage. We find significant anisotropies in the temperature and entropy profiles, with a region of lower temp…
The Black Hole Spin and Soft X-Ray Excess of the Luminous Seyfert Galaxy Fairall 9
Fabian, Andrew C.; Brenneman, Laura W.; Reynolds, Christopher S. +4 more
We present an analysis of all XMM-Newton and Suzaku X-ray spectra of the nearby luminous Seyfert galaxy Fairall 9. Confirming previous analyses, we find robust evidence for a broad iron line associated with X-ray reflection from the innermost accretion disk. By fitting a spectral model that includes a relativistically ionized reflection component,…
Initiation of Coronal Mass Ejection and Associated Flare Caused by Helical Kink Instability Observed by SDO/AIA
Cho, K. -S.; Park, Sung-Hong; Kumar, Pankaj +2 more
In this paper, we present multiwavelength observations of helical kink instability as a trigger of a coronal mass ejection (CME) which occurred in active region NOAA 11163 on 2011 February 24. The CME was associated with an M3.5 limb flare. High-resolution observations from the Solar Dynamics Observatory/Atmospheric Imaging Assembly suggest the de…
Spatial and temporal variations in Titan's surface temperatures from Cassini CIRS observations
Irwin, P. G. J.; Teanby, N. A.; de Kok, R. +4 more
We report a wide-ranging study of Titan's surface temperatures by analysis of the Moon's outgoing radiance through a spectral window in the thermal infrared at 19 µm (530 cm-1) characterized by lower atmospheric opacity. We begin by modeling Cassini Composite Infrared Spectrometer (CIRS) far infrared spectra collected in the perio…
Multiple Plasma Ejections and Intermittent Nature of Magnetic Reconnection in Solar Chromospheric Anemone Jets
Shibata, K.; Isobe, H.; Singh, K. A. P. +2 more
The recent discovery of chromospheric anemone jets with the Solar Optical Telescope (SOT) on board Hinode has shown an indirect evidence of magnetic reconnection in the solar chromosphere. However, the basic nature of magnetic reconnection in chromosphere is still unclear. We studied nine chromospheric anemone jets from SOT/Hinode using Ca II H fi…
Probing the Role of Carbon in Ultraviolet Extinction along Galactic Sight Lines
Murthy, J.; Babu, B. R. S.; Parvathi, V. S. +1 more
We report previously undetermined interstellar gas and dust-phase carbon abundances along 15 Galactic sight lines based on archival data of the strong 1334.5323 Å transition observed with the Space Telescope Imaging Spectrograph. These are combined with previously reported carbon measurements along six sight lines to produce a complete sample of i…
Chronology of deposition and alteration in the Mawrth Vallis region, Mars
Mangold, N.; Bibring, J. -P.; Loizeau, D. +2 more
The Mawrth Vallis area displays some of the largest phyllosilicate-rich outcrops of Mars, on Noachian highlands. The Mawrth Vallis region is located just at the dichotomy boundary between the Noachian highlands and the younger, northern lowlands. A large, thick, layered clay-rich unit is present throughout the inter-crater plateaus. Clay-rich laye…
Variability-selected Low-luminosity Active Galactic Nuclei in the 4 Ms Chandra Deep Field-South
Lehmer, B. D.; Alexander, D. M.; Bauer, F. E. +8 more
The 4 Ms Chandra Deep Field-South (CDF-S) and other deep X-ray surveys have been highly effective at selecting active galactic nuclei (AGNs). However, cosmologically distant low-luminosity AGNs (LLAGNs) have remained a challenge to identify due to significant contribution from the host galaxy. We identify long-term X-ray variability (~month-years,…
The Spectral Energy Distributions and Infrared Luminosities of z ≈ 2 Dust-obscured Galaxies from Herschel and Spitzer
Dey, Arjun; Bussmann, R. S.; Alberts, Stacey +6 more
Dust-obscured galaxies (DOGs) are a subset of high-redshift (z ≈ 2) optically-faint ultra-luminous infrared galaxies (ULIRGs, e.g., L IR > 1012 L ⊙). We present new far-infrared photometry, at 250, 350, and 500 µm (observed-frame), from the Herschel Space Telescope for a large sample of 113 DOGs with spect…