Physical Sciences and Mathematics Commons^™

Variability In X-Ray Line Ratios In Helium-Like Ions Of Massive Stars: The Wind-Driven Case, Richard Ignace, Z. Damrau, K. T. Hole

ETSU Faculty Works

Context. High spectral resolution and long exposure times are providing unprecedented levels of data quality of massive stars at X-ray wavelengths.

Aims. A key diagnostic of the X-ray emitting plasma are the fir lines for He-like triplets. In particular, owing to radiative pumping effects, the forbidden-to-intercombination line luminosity ratio, R = f∕i, can be used to determine the proximity of the hot plasma to the UV-bright photospheres of massive stars. Moreover, the era of large observing programs additionally allows for investigation of line variability.

Methods. This contribution is the second to explore how variability in the line …

The Polarization Mode Of The Auroral Radio Emission From The Early-Type Star Hd 142301, P. Leto, C. Trigilio, Lidi M. Oskinova, Richard Ignace, C. S. Buemi, G. Umana, F. Cavallaro, A. Ingallinera, F. Bufano, N. M. Phillips, C. Agliozzo, L. Cerrigone, H. Todt, S. Riggi, F. Leone

ETSU Faculty Works

We report the detection of the auroral radio emission from the early-type magnetic star HD 142301. New VLA observations of HD 142301 detected highly polarized amplified emission occurring at fixed stellar orientations. The coherent emission mechanism responsible for the stellar auroral radio emission amplifies the radiation within a narrow beam, making the star where this phenomenon occurs similar to a radio lighthouse. The elementary emission process responsible for the auroral radiation mainly amplifies one of the two magneto-ionic modes of the electromagnetic wave. This explains why the auroral pulses are highly circularly polarized. The auroral radio emission of HD 142301 …

The Mimes Survey Of Magnetism In Massive Stars: Introduction And Overview, G. A. Wade, C. Neiner, E. Alecian, H. H. Grunhunt, V. Petit, B. Batz, D. A. Bohlender, D. H. Cohen, H. F. Henrichs, O. Kochukhov, J. D. Landstreet, N. Manset, F. Martins, S. Mathis, M. E. Oksala, S. P. Owocki, Th. Rivinius, M. E. Schultz, J. O. Sundqvist, R. H.D. Townsend, A. Doula, J. C. Bouret, J. Braithwaite, M. Briquet, A. C. Carciofi, A. David-Uraz, C. P. Folsom, A. W. Fullerton, B. Leroy, W. L.F. Marcolino, A. F.J. Moffat, Y. Naze, N. St Louis, M. Auriere, S. Bagnulo, J. D. Bailey, R. H. Barba, A. Blazere, T. Bohm, C. Catala, J-F Donati, L. Ferrario, D. Harrington, I. D. Howarth, Richard Ignace, L. Kaper, T. Luftinger, R. Prinja, J. S. Vink, W. W. Weiss, I. Yakunin

ETSU Faculty Works

The MiMeS (Magnetism in Massive Stars) project is a large-scale, high-resolution, sensitive spectropolarimetric investigation of the magnetic properties of O- and early B-type stars. Initiated in 2008 and completed in 2013, the project was supported by three Large Program allocations, as well as various programmes initiated by independent principal investigators, and archival resources. Ultimately, over 4800 circularly polarized spectra of 560 O and B stars were collected with the instruments ESPaDOnS (Echelle SpectroPolarimetric Device for the Observation of Stars) at the Canada–France–Hawaii Telescope, Narval at the Télescope Bernard Lyot and HARPSpol at the European Southern Observatory La Silla 3.6 m …