Search Publications
Morphology and variability of the Titan ringlet and Huygens ringlet edges
Colwell, Joshua E.; Esposito, Larry W.; Jerousek, Richard G.
We present a forward modeling approach for determining, in part, the ring particle spatial distribution in the vicinity of sharp ring or ringlet edges. Synthetic edge occultation profiles are computed based on a two-parameter particle spatial distribution model. One parameter, h, characterizes the vertical extent of the ring and the other, δ, char…
A close look at the Centaurus A group of galaxies. III. Recent star formation histories of late-type dwarfs around M 83
Crnojević, D.; Grebel, E. K.; Cole, A. A.
Aims: We study the resolved stellar populations of dwarf galaxies in the nearby Centaurus A/M 83 group of galaxies. Our goal is to characterize their evolutionary history and to investigate eventual similarities or differences with the dwarf population in other group environments.
Methods: This work presents the analysis of five late-typ…
The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and γ-rays
Pottschmidt, Katja; Wilms, Jörn; Bower, Geoffrey C. +7 more
In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV γ-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and …
Far-Infrared Luminous Supernova Remnant Kes 17
Onaka, Takashi; Jeong, Woong-Seob; Koo, Bon-Chul +4 more
We present the results of infrared (IR; 2.5-160 µm) observations of the supernova remnant (SNR) Kes 17 based on the data obtained with the AKARI and Spitzer satellites. We first detect bright continuum emission of its western shell in the mid- and far-IR wavebands together with its near-IR molecular line emission. We also detect hidden mid-I…
Dipping in CygnusX-2 in a multi-wavelength campaign due to absorption of extended ADC emission
Wilms, J.; Spencer, R. E.; Hanke, M. +5 more
We report results of one-day simultaneous multiwavelength observations of CygnusX-2 using XMM, Chandra, the European VLBI Network and the XMM Optical Monitor. During the observations, the source did not exhibit Z-track movement, but remained in the vicinity of the soft apex. It was in a radio quiescent/quiet state of <150 µJy. Strong dip …
Unraveling the Nature of Unidentified High Galactic Latitude Fermi/LAT Gamma-Ray Sources With Suzaku
Cheung, C. C.; Gehrels, N.; Kanai, Y. +13 more
Here we report on the results of deep X-ray follow-up observations of four unidentified γ-ray sources detected by the Fermi/LAT instrument at high Galactic latitudes using the X-ray Imaging Spectrometers on board the Suzaku satellite. All of the studied objects were detected with high significance during the first three months of Fermi/LAT operati…
Are recent solar heavy element abundances consistent with helioseismology?
Basu, Sarbani; Antia, H. M.
During the last decade the abundances of heavy elements in the Sun have been revised downwards leading to serious discrepancy between solar models constructed using these abundances and the available seismic data. Much of these downward revision of abundances of Oxygen and other light elements was attributed to use of improved 3D solar atmospheric…
Spectral components in the bright, long GRB 061007: properties of the photosphere and the nature of the outflow
Larsson, J.; McGlynn, S.; Yamaoka, K. +4 more
We present a time-resolved spectral analysis of the bright, long GRB 061007 (z= 1.261) using Swift and Suzaku data. We find that the prompt emission of the burst can be equally well explained by a photospheric component together with a power law as by a Band function, and we explore the implications of the former model. The photospheric component,…
Deep Impact, Stardust-NExT and the behavior of Comet 9P/Tempel 1 from 1997 to 2010
A'Hearn, M. F.; Vincent, J. -B.; Bhatt, B. C. +55 more
We present observational data for Comet 9P/Tempel 1 taken from 1997 through 2010 in an international collaboration in support of the Deep Impact and Stardust-NExT missions. The data were obtained to characterize the nucleus prior to the Deep Impact 2005 encounter, and to enable us to understand the rotation state in order to make a time of arrival…
N II λλ5668-5712: A New Class of Spectral Features in Eta Carinae
Davidson, Kris; Mehner, Andrea; Ferland, Gary J.
We report on the N II λλ5668-5712 emission and absorption lines in the spectrum of η Carinae. Spectral lines of the stellar wind regions can be classified into four physically distinct categories: (1) low-excitation emission such as H I and Fe II, (2) higher-excitation He I features, (3) the N II lines discussed in this paper, and (4) He II emissi…