Search Publications
A New Investigation of the Binary HD 48099
Martins, F.; Gosset, E.; Nazé, Y. +5 more
With an orbital period of about 3.078 days, the double-lined spectroscopic binary HD 48099 is, until now, the only short-period O+O system known in the Mon OB2 association. Even though an orbital solution has already been derived for this system, few information are available about the individual stars. We present, in this paper, the results of a …
The Computed Infrared Spectra of a Variety of [FePAH]+ Complexes: Mid- and Far-Infrared Features
Joblin, C.; Simon, A.
The effects of the π-coordination of an Fe atom on the mid- and far-infrared spectra of a mixture of cationic polycyclic aromatic hydrocarbons (PAHs), e.g., pyrene (C16H10), anthanthrene (C22H12), coronene (C24H12), ovalene (C32H14), circumpyrene (C42
Suzaku Monitoring of the Seyfert 1 Galaxy NGC 5548: Warm Absorber Location and Its Implication for Cosmic Feedback
Liu, Y.; Binette, L.; Elvis, M. +12 more
We present a 2 month Suzaku X-ray monitoring of the Seyfert 1 galaxy NGC 5548. The campaign consists of seven observations (with exposure time of ~30 ks each), separated by ~1 week. This paper focus on the X-ray Imaging Spectrometer data of NGC 5548. We analyze the response in the opacity of the gas that forms the well-known ionized absorber in th…
Evolution of the Synchrotron and Inverse Compton Emissions of the Low-energy-peaked BL Lac Object S5 0716+714
Zhang, Y. H.
This paper presents a detailed analysis of the temporal and spectral variability of the low-energy peaked BL Lac object S5 0716+714 with a long (~74 ks) X-ray observation performed by XMM-Newton on 2007 September 24-25. The source experiences recurrent flares on timescales of hours. The soft X-ray variations, up to a factor of ~4, are much stronge…
Gas Emission from Debris Disks Around A and F Stars
Brandeker, Alexis; Wu, Yanqin; Zagorovsky, Kyryl
Gas has been detected in a number of debris disk systems. This gas may have arisen from grain sublimation or grain photodesorption. It interacts with the surrounding dust grains through a number of charge and heat exchanges. Studying the chemical composition and physical state of this gas can therefore reveal much about the dust component in these…
On the "Extended" Solar Cycle in Coronal Emission
Sheeley, N. R., Jr.; Wang, Y. -M.; Rich, N. B. +1 more
Butterfly diagrams (latitude-time plots) of coronal emission show a zone of enhanced brightness that appears near the poles just after solar maximum and migrates toward lower latitudes; a bifurcation seems to occur at sunspot minimum, with one branch continuing to migrate equatorward with the sunspots of the new cycle and the other branch heading …
Radial Evolution of Solar Wind Turbulence during Earth and Ulysses Alignment of 2007 August
Balogh, A.; Bavassano, B.; Bruno, R. +4 more
At the end of 2007 August, during the minimum of solar cycle 23, a lineup of Earth and Ulysses occurred, giving the opportunity to analyze, for the first time, the same plasma sample at different observation points, namely at 1 and 1.4 AU. In particular, it allowed us to study the radial evolution of solar wind turbulence typical of fast wind stre…
New Evidence for a Black Hole in the Compact Binary Cygnus X-3
Titarchuk, Lev; Shaposhnikov, Nikolai; Shrader, Chris R.
The bright and highly variable X-ray and radio source known as Cygnus X-3 was among the first X-ray sources discovered, yet it remains in many ways an enigma. It is known to consist of a massive, Wolf-Rayet primary in an extremely tight orbit with a compact object. However, one of the most basic of parameters—the mass of the compact object—is not …
Characterizing Complexity in Solar Magnetogram Data Using a Wavelet-based Segmentation Method
Gallagher, P. T.; McAteer, R. T. J.; Conlon, P. A. +4 more
The multifractal nature of solar photospheric magnetic structures is studied using the two-dimensional wavelet transform modulus maxima (WTMM) method. This relies on computing partition functions from the wavelet transform skeleton defined by the WTMM method. This skeleton provides an adaptive space-scale partition of the fractal distribution unde…
First Orbital Solution for the Non-thermal Emitter Cyg OB2 No. 9
Barbieri, C.; Damerdji, Y.; Morel, T. +7 more
After the first detection of its binary nature, the spectroscopic monitoring of the non-thermal radio emitter Cyg OB2 No. 9 (P = 2.4 yr) has continued, doubling the number of available spectra of the star. Since the discovery paper of 2008, a second periastron passage has occurred in 2009 February. Using a variety of techniques, the radial velocit…