Search Publications
Phase resolved X-ray spectroscopy of HDE 228766: Probing the wind of an extreme Of+/WNLha star
Nazé, Y.; Rauw, G.; Manfroid, J. +3 more
Context. HDE 228766 is a very massive binary system hosting a secondary component, which is probably in an intermediate evolutionary stage between an Of supergiant and an WN star. The wind of this star collides with the wind of its O8 II companion, leading to relatively strong X-ray emission.
Aims: Measuring the orbital variations of the line…
Blue Straggler Star Populations in Globular Clusters. I. Dynamical Properties of Blue Straggler Stars in NGC 3201, NGC 6218, and ω Centauri
Puzia, Thomas H.; Simunovic, Mirko
We present the first dynamical study of blue straggler stars (BSSs) in three Galactic globular clusters, NGC 3201, NGC 5139 (ω Cen), and NGC 6218, based on medium-resolution spectroscopy (R ≈ 10, 000) obtained with the Inamori-Magellan Areal Camera & Spectrograph mounted at the 6.5 m Baade Magellan telescope. Our BSS candidate selection techni…
The effect of spatial resolution on optical and near-IR studies of stellar clusters: implications for the origin of the red excess
Schirmer, M.; Bastian, N.; Adamo, A. +6 more
Recent ground-based near-IR (NIR) studies of stellar clusters in nearby galaxies have suggested that young clusters remain embedded for 7-10 Myr in their progenitor molecular cloud, in conflict with optical-based studies which find that clusters are exposed after 1-3 Myr. Here, we investigate the role that spatial resolution plays in this apparent…
Formation of the high-energy ion population in the earth's magnetotail: spacecraft observations and theoretical models
Petrukovich, A. A.; Artemyev, A. V.; Lutsenko, V. N. +1 more
We investigate the formation of the high-energy (E ∈ [20,600] keV) ion population in the earth's magnetotail. We collect statistics of 4 years of Interball / Tail observations (1995-1998) in the vicinity of the neutral plane in the magnetotail region (X <-17 RE, |Y| ≤ 20 RE in geocentric solar magnetospheric…
The puzzling X-ray continuum of the quasar MR 2251-178
Grosso, N.; Porquet, D.; Reeves, J. N. +3 more
We report on a comprehensive X-ray spectral analysis of the nearby radio-quiet quasar MR 2251-178, based on the long-look (∼400 ks) XMM-Newton observation carried out in 2011 November. As the properties of the multiphase warm absorber (thoroughly discussed in a recent, complementary work) hint at a steep photoionizing continuum, here we investigat…
Herschel Observations of Dust around the High-mass X-Ray Binary GX 301-2
Chaty, S.; Rahoui, F.; Servillat, M. +2 more
We aim at characterizing the structure of the gas and dust around the high-mass X-ray binary GX 301-2, a highly obscured X-ray binary hosting a hypergiant (HG) star and a neutron star, in order to better constrain its evolution. We used Herschel PACS to observe GX 301-2 in the far infrared and completed the spectral energy distribution of the sour…
The Shock-induced Star Formation Sequence Resulting from a Constant Spiral Pattern Speed
Martínez-García, Eric E.; Puerari, Ivânio
We utilize a suite of multiwavelength data of nine nearby spirals to analyze the shock-induced star formation sequence that may result from a constant spiral pattern speed. The sequence involves tracers as the H I, CO 24 µm, and FUV, where the spiral arms were analyzed with Fourier techniques in order to obtain their azimuthal phases as a fu…
Random dust charge fluctuations in the near-Enceladus plasma
Yaroshenko, V. V.; Lühr, H.
Stochastic dust charge fluctuations have been studied in the light of Cassini data on the near-Enceladus plasma environment. Estimates of fluctuation time scales showed that this process can be of importance for the grains emanating from the icy moon. The analytical modeling predicts that in the dust-loaded Enceladus plasma a majority of the grain…
The CoRoT Discovery of a Unique Triple-mode Cepheid in the Galaxy
Poretti, E.; Baglin, A.; Weiss, W. W.
The exploitation of the CoRoT treasure of stars observed in the exoplanetary field allowed the detection of a unusual triple-mode Cepheid in the Milky Way, CoRoT 0223989566. The two modes with the largest amplitudes and a period ratio of 0.80 are identified with the first (P 1 = 1.29 days) and second (P 2 = 1.03 days) radial …
Structure of a reconnection layer poleward of the cusp: Extreme density asymmetry and a guide field
Russell, C. T.; Farrugia, C. J.; Torbert, R. B. +7 more
We present Polar observations of a reconnection layer during an inbound pass at high northern latitudes. The interplanetary field of 20 nT pointed strongly northward continuously for 13 h. Reverse polar cap convection observed repeatedly by the DMSP F13 satellite provided direct evidence of continued reconnection. Polar observed sunward and southw…