Search Publications
Dual Origin of Aerosols in Titan's Detached Haze Layer
Rodriguez, S.; West, R. A.; Brahic, A. +3 more
We have analyzed scattered light profiles from the Cassini Imaging Science Subsystem, taken at the limb and at several large phase angles. We also used results from an occultation observed by Ultraviolet Imaging Spectrograph in the ultraviolet. We found that particles responsible for the scattering in the detached haze have an effective radius aro…
A Light-curve Model of the Symbiotic Nova PU Vul (1979): A Very Quiet Explosion with Long-lasting Flat Peak
Cassatella, Angelo; Kato, Mariko; Hachisu, Izumi +1 more
We present a light-curve model of the symbiotic nova PU Vul (Nova Vulpeculae 1979) that shows a long-lasting flat peak with no spectral indication of wind mass loss before decline. Our quasi-evolution models consisting of a series of static solutions explain both the optical flat peak and ultraviolet (UV) light curve simultaneously. The white dwar…
Soft Time Lags in the X-Ray Emission of Mrk 1040
Dewangan, Gulab; Misra, Ranjeev; Tripathi, Shruti +1 more
Temporal analysis of X-ray binaries and active galactic nuclei (AGNs) have shown that hard X-rays react to variation of soft ones after a time delay. The opposite trend, or soft lag, has only been seen in a few rare quasi-periodic oscillations in X-ray binaries and recently for the AGN 1H 0707-495, on short timescales of ~103 s. Here, w…
Clustering Properties of Far-infrared Sources in Hi-GAL Science Demonstration Phase Fields
Testi, L.; Elia, D.; Schisano, E. +9 more
We use a minimum spanning tree (MST) algorithm to characterize the spatial distribution of Galactic far-IR sources and derive their clustering properties. We aim to reveal the spatial imprint of different types of star-forming processes, e.g., isolated spontaneous fragmentation of dense molecular clouds, or events of triggered star formation aroun…
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…
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…
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…
On the Nature of the Spectral Line Broadening in Solar Coronal Dimmings
Zhukov, A. N.; Dolla, L. R.
We analyze the profiles of iron emission lines observed in solar coronal dimmings associated with coronal mass ejections, using the EUV Imaging Spectrometer on board Hinode. We quantify line profile distortions with empirical coefficients (asymmetry and peakedness) that compare the fitted Gaussian to the data. We find that the apparent line broade…
Plasma Heating in the Very Early and Decay Phases of Solar Flares
Siarkowski, M.; Falewicz, R.; Rudawy, P.
In this paper, we analyze the energy budgets of two single-loop solar flares under the assumption that non-thermal electrons (NTEs) are the only source of plasma heating during all phases of both events. The flares were observed by RHESSI and GOES on 2002 September 20 and 2002 March 17, respectively. For both investigated flares we derived the ene…