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Full-Text Articles in Physical Sciences and Mathematics
A Coordinated X-Ray And Optical Campaign Of The Nearest Massive Eclipsing Binary, Δ Orionis Aa: Ii. X-Ray Variability., J. Nichols, D. P. Huenemoerder, M. F. Corcoran, W. Waldron, Y. Nazé, A. M. T. Pollock, A. F. J. Moffat, J. Lauer, T. Shenar, C. M. P. Russell, N. D. Richardson, H. Pablo, N. R. Evans, K. Hamaguchi, T. Gull, W.-R. Hamann, L. Oskinova, R. Ignace, Jennifer L. Hoffman, K. T. Hole, J. R. Lomax
A Coordinated X-Ray And Optical Campaign Of The Nearest Massive Eclipsing Binary, Δ Orionis Aa: Ii. X-Ray Variability., J. Nichols, D. P. Huenemoerder, M. F. Corcoran, W. Waldron, Y. Nazé, A. M. T. Pollock, A. F. J. Moffat, J. Lauer, T. Shenar, C. M. P. Russell, N. D. Richardson, H. Pablo, N. R. Evans, K. Hamaguchi, T. Gull, W.-R. Hamann, L. Oskinova, R. Ignace, Jennifer L. Hoffman, K. T. Hole, J. R. Lomax
Richard Ignace
We present time-resolved and phase-resolved variability studies of an extensive X-ray high-resolution spectral data set of the δ Ori Aa binary system. The four observations, obtained with Chandra ACIS HETGS, have a total exposure time of ≈ 479 ks and provide nearly complete binary phase coverage. Variability of the total X-ray flux in the range of 5–25 Å is confirmed, with a maximum amplitude of about ±15% within a single ≈ 125 ks observation. Periods of 4.76 and 2.04 days are found in the total X-ray flux, as well as an apparent overall increase in the flux level throughout the …
A Coordinated X-Ray And Optical Campaign Of The Nearest Massive Eclipsing Binary, Δ Ori Aa: I. Overview Of The X-Ray Spectrum., M. F. Corcoran, J. S. Nichols, H. Pablo, T. Shenar, A. M. T. Pollock, W. L. Waldron, A. F. J. Moffat, N. D. Richardson, C. M. P. Russell, K. Hamaguchi, D. P. Huenemoerder, L. Oskinova, W.-R. Hamann, Y. Nazé, R. Ignace, N. R. Evans, J. R. Lomax, J. L. Hoffman, K. Gayley, S. P. Owocki, M. Leutenegger, T. R. Gull, K. T. Hole, J. Lauer, R. C. Iping
A Coordinated X-Ray And Optical Campaign Of The Nearest Massive Eclipsing Binary, Δ Ori Aa: I. Overview Of The X-Ray Spectrum., M. F. Corcoran, J. S. Nichols, H. Pablo, T. Shenar, A. M. T. Pollock, W. L. Waldron, A. F. J. Moffat, N. D. Richardson, C. M. P. Russell, K. Hamaguchi, D. P. Huenemoerder, L. Oskinova, W.-R. Hamann, Y. Nazé, R. Ignace, N. R. Evans, J. R. Lomax, J. L. Hoffman, K. Gayley, S. P. Owocki, M. Leutenegger, T. R. Gull, K. T. Hole, J. Lauer, R. C. Iping
Richard Ignace
A Coordinated X-Ray And Optical Campaign Of The Nearest Massive Eclipsing Binary, Δ Orionis Aa. Iii. Analysis Of Optical Photometric (Most) And Spectroscopic (Ground Based) Variations., Herbert Pablo, Noel D. Richardson, Anthony F. J. Moffat, Michael Corcoran, Tomer Shenar, Omar Benvenuto, Jim Fuller, Yaël Nazé, Jennifer L. Hoffman, Anatoly Miroshnichenko, Jesús Maíz Apellániz, Nancy Evans, Thomas Eversberg, Ken Gayley, Ted Gull, Kenji Hamaguchi, Wolf-Rainer Hamann, Huib Henrichs, Tabetha Hole, Richard Ignace, Rosina Iping, Jennifer Lauer, Maurice Leutenegger, Jamie Lomax, Joy Nichols, Lida Oskinova, Stan Owocki, Andy Pollock, Christopher M. P. Russell, Wayne Waldron, Christian Buil, Thierry Garrel, Keith Graham, Bernard Heathcote, Thierry Lemoult, Dong Li, Benjamin Mauclaire, Mike Potter, Jose Ribeiro, Jaymie Matthews, Chris Cameron, David Guenther, Rainer Kuschnig, Jason Rowe, Slavek Rucinski, Dimitar Sasselov, Werner Weiss
A Coordinated X-Ray And Optical Campaign Of The Nearest Massive Eclipsing Binary, Δ Orionis Aa. Iii. Analysis Of Optical Photometric (Most) And Spectroscopic (Ground Based) Variations., Herbert Pablo, Noel D. Richardson, Anthony F. J. Moffat, Michael Corcoran, Tomer Shenar, Omar Benvenuto, Jim Fuller, Yaël Nazé, Jennifer L. Hoffman, Anatoly Miroshnichenko, Jesús Maíz Apellániz, Nancy Evans, Thomas Eversberg, Ken Gayley, Ted Gull, Kenji Hamaguchi, Wolf-Rainer Hamann, Huib Henrichs, Tabetha Hole, Richard Ignace, Rosina Iping, Jennifer Lauer, Maurice Leutenegger, Jamie Lomax, Joy Nichols, Lida Oskinova, Stan Owocki, Andy Pollock, Christopher M. P. Russell, Wayne Waldron, Christian Buil, Thierry Garrel, Keith Graham, Bernard Heathcote, Thierry Lemoult, Dong Li, Benjamin Mauclaire, Mike Potter, Jose Ribeiro, Jaymie Matthews, Chris Cameron, David Guenther, Rainer Kuschnig, Jason Rowe, Slavek Rucinski, Dimitar Sasselov, Werner Weiss
Richard Ignace
Polarimetric Modeling Of Corotating Interaction Regions (Cirs) Threading Massive-Star Winds., Richard Ignace, N. St-Louis, F. Proulx-Giraldeau
Polarimetric Modeling Of Corotating Interaction Regions (Cirs) Threading Massive-Star Winds., Richard Ignace, N. St-Louis, F. Proulx-Giraldeau
Richard Ignace
Massive star winds are complex radiation-hydrodynamic (sometimes magnetohydrodynamic) outflows that are propelled by their enormously strong luminosities. The winds are often found to be structured and variable, but can also display periodic or quasi-periodic behavior in a variety of wind diagnostics. The regular variations observed in putatively single stars, especially in UV wind lines, have often been attributed to corotating interaction regions (CIRs) like those seen in the solar wind. We present light curves for variable polarization from winds with CIR structures. We develop a model for a time-independent CIR based on a kinematical description. Assuming optically thin electron scattering, …
New Multiwavelength Observations Of The Of?P Star Cpd -28◦ 2561., S. Hubrig, M. Schöller, A. F. Kholtygin, H. Tsumura, A. Hoshino, S. Kitamoto, L. Oskinova, R. Ignace, H. Todt, I. Ilyin
New Multiwavelength Observations Of The Of?P Star Cpd -28◦ 2561., S. Hubrig, M. Schöller, A. F. Kholtygin, H. Tsumura, A. Hoshino, S. Kitamoto, L. Oskinova, R. Ignace, H. Todt, I. Ilyin
Richard Ignace
A rather strong mean longitudinal magnetic field of the order of a few hundred gauss was detected a few years ago in the Of?p star CPD −28° 2561 using FORS2 (FOcal Reducer low dispersion Spectrograph 2) low-resolution spectropolarimetric observations. In this work, we present additional low-resolution spectropolarimetric observations obtained during several weeks in 2013 December using FORS 2 mounted at the 8-m Antu telescope of the Very Large Telescope (VLT). These observations cover a little less than half of the stellar rotation period of 73.41 d mentioned in the literature. The behaviour of the mean longitudinal magnetic field is consistent …
On X-Ray Pulsations In Beta Cephei-Type Variables., L. M. Oskinova, H. Todt, D. P. Huenemoerder, S. Hubrig, Richard Ignace, W.-R. Hamann, L. Balona
On X-Ray Pulsations In Beta Cephei-Type Variables., L. M. Oskinova, H. Todt, D. P. Huenemoerder, S. Hubrig, Richard Ignace, W.-R. Hamann, L. Balona
Richard Ignace
Beta Cephei-type variables are early B-type stars that are characterized by oscillations observable in their optical light curves. At least one Beta Cep-variable also shows periodic variability in X-rays. Here we study the X-ray light curves in a sample of beta Cep-variables to investigate how common X-ray pulsations are for this type of stars. We searched the Chandra and XMM-Newton X-ray archives and selected stars that were observed by these telescopes for at least three optical pulsational periods. We retrieved and analyzed the X-ray data for kappa Sco, beta Cru, and alpha Vir. The X-ray light curves of these objects …