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Related papers: On the iron Kalpha complex in magnetic cataclysmic…

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We present constraints on the structure of the chromosphere from observations of the Ca II H line profile near and off the solar limb. We obtained a data set of the Ca II H line in a field of view extending 20" across the limb. We analyzed…

Solar and Stellar Astrophysics · Physics 2015-05-28 C. Beck , R. Rezaei

Magnetic chemically peculiar (mCP) stars are strongly magnetic upper main-sequence stars that exhibit light rotational variability due to an uneven surface distribution of certain peculiar elements, which may appear in phase at certain…

It is shown that the dielectronic satellites (DES) dominate X-ray spectral formation in the 6.7 keV K-alpha complex of Fe XXV at temperatures below that of maximum abundance in collisional ionization equilibrium T_m. Owing to their extreme…

Astrophysics · Physics 2007-08-07 Justin Oelgoetz , Anil K. Pradhan

We present a set of Roche tomography reconstructions of the secondary stars in the cataclysmic variables AM Her, QQ Vul, IP Peg and HU Aqr. The image reconstructions show distinct asymmetries in the irradiation pattern for all four systems…

Astrophysics · Physics 2009-11-07 C. A. Watson , V. S. Dhillon , R. G. M. Rutten , A. D. Schwope

The spectral and magnetic properties and variability of the B2Vnp emission-line magnetosphere star HR7355 were analyzed. The object rotates at almost 90% of the critical value, meaning it is a magnetic star for which oblateness and gravity…

Solar and Stellar Astrophysics · Physics 2015-06-12 Th. Rivinius , R. H. D. Townsend , O. Kochukhov , S. Štefl , D. Baade , L. Barrera , Th. Szeifert

The magnetic cataclysmic variable AE Aquarii hosts a rapidly rotating white dwarf which is thought to expel most of the material streaming onto it. Observations of AE Aqr have been obtained in the wavelength range of 5 - 70 microns with the…

Astrophysics · Physics 2011-02-11 G. Dubus , R. E. Taam , C. Hull , D. M. Watson , J. C. Mauerhan

For early type magnetic stars slow, at most moderate rotational velocities have been considered an observational fact. The detection of a multi-kilogauss magnetic field in the B2Vpn star with P approx. 0.52d and v sin approx. 300km/s has…

Solar and Stellar Astrophysics · Physics 2015-05-20 Th. Rivinius , R. H. D. Townsend , S. Štefl , D. Baade

We present new, high signal-to-noise ratio results from a Monte Carlo study of the properties of the Compton shoulder of the Fe Kalpha emission line in the toroidal X-ray reprocessor model of Murphy & Yaqoob (2009, MNRAS, 397, 1549). The…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Tahir Yaqoob , Kendrah D. Murphy

We have investigated the ionisation structure of the post-shock regions of magnetic cataclysmic variables using an analytic density and temperature structure model in which effects due to bremsstrahlung and cyclotron cooling are considered.…

Astrophysics · Physics 2009-11-06 Kinwah Wu , Mark Cropper , Gavin Ramsay

We analyze a 1-hour time series of Ca II H intensity spectra and polarimetric spectra around 630 nm to derive the signature of the chromospheric heating and to investigate its relation to magnetic fields. We derived several characteristic…

Astrophysics · Physics 2008-02-08 C. Beck , W. Schmidt , R. Rezaei , W. Rammacher

49 Cam is a cool magnetic chemically peculiar star which has been noted for showing strong, complex Zeeman linear polarisation signatures. This paper describes magnetic and chemical surface maps obtained for 49 Cam using the INVERS10…

Solar and Stellar Astrophysics · Physics 2017-08-16 J. Silvester , O. Kochukhov , N. Rusomarov , G. A. Wade

Spin-filtered time-of-flight photoelectron momentum microscopy reveals a systematic variation of the band structure within a series of highly spin-polarized ferromagnetic Heusler compounds with increasing number of valence electrons…

Materials Science · Physics 2021-02-10 S. Chernov , C. Lidig , O. Fedchenko , M. Jourdan , G. Schönhense , H. J. Elmers

Magnetic Doppler imaging from four Stokes parameter observations has uncovered a new level of complexity of stellar magnetic fields previously not known. This new information is of interest to the evolution and structure of magnetic fields…

Solar and Stellar Astrophysics · Physics 2015-06-22 N. Rusomarov , O. Kochukhov , N. Piskunov

Hard X-ray light curves and spectral parameters from our analysis of X-ray data of five AM Her type systems - V2301 Oph, V1432 Aql, EP Draconis, GG Leonis, V834 Cen, and one intermediate polar - TV Col, observed using the Rossi X-ray Timing…

Astrophysics · Physics 2007-05-23 K. P. Singh , V. R. Rana , K. Mukerjee , P. Barrett , E. M. Schlegel

High-quality phase-resolved optical spectropolarimetry is presented for the magnetic cataclysmic variable V884 Her. The overall circular polarization during active accretion states is low and only slightly variable in the range 5000-8000A.…

Astrophysics · Physics 2009-10-31 G. D. Schmidt , L. Ferrario , D. T. Wickramasinghe , P. S. Smith

We have obtained simultaneous photometric and spectroscopic observations of the cataclysmic variable 1RXS J064434.5+334451. We have calibrated the spectra for slit losses using the simultaneous photometry allowing to construct reliable…

Solar and Stellar Astrophysics · Physics 2016-10-26 J. V. Hernández Santisteban , J. Echevarría , R. Michel , R. Costero

We analyse the transmission spectra of KELT-20b/MASCARA-2b to search for possible thermal inversion agents. The data consist of three transits obtained using HARPSN and one using CARMENES. We removed stellar and telluric lines before…

Earth and Planetary Astrophysics · Physics 2020-10-14 Stevanus K. Nugroho , Neale P. Gibson , Ernst J. W. de Mooij , Chris A. Watson , Hajime Kawahara , Stephanie Merritt

A set of strongly magnetized accreting white dwarfs (polars) shows quasi-periodic oscillations (QPOs) with frequency about a Hz in their optical luminosity. These Hz-frequency QPOs are thought to be generated by intensity variations of the…

High Energy Astrophysical Phenomena · Physics 2017-12-27 Prasanta Bera , Dipankar Bhattacharya

The HH54 shock is a Herbig-Haro object, located in the nearby Chamaeleon II cloud. Observed CO line profiles are due to a complex distribution in density, temperature, velocity, and geometry. Resolving the HH54 shock wave in the…

The Heusler compound Co2MnGa is a topological semimetal with intriguing electronic and magnetic properties, making it a promising candidate for spintronic applications. This study systematically investigates the effects of substrate…