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Related papers: Modeling UX Ursae Majoris: An abundance of challen…

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The stellar-wind structure in high-mass X-ray binaries (HMXBs) is investigated through modelling of their ultraviolet (UV) resonance lines. For the OB supergiants in two systems, Vela X-1 and 4U1700-37, high-resolution UV spectra are…

Astrophysics · Physics 2009-11-06 Jacco Th. van Loon , Lex Kaper , Godelieve Hammerschlag-Hensberge

Far-ultraviolet (FUV) radiation is a driving source of photochemistry in planetary atmospheres. Proper interpretation of atmospheric observations requires a full understanding of the radiation environment that a planet is exposed to. Using…

Earth and Planetary Astrophysics · Physics 2026-01-09 Patrick R. Behr , Kevin France , Nicholas Kruczek , Nicholas Nell , Brian Fleming , Stefan Ulrich , Girish M. Duvvuri , Amy Louca , Yamila Miguel

We present a synthetic spectral analysis of Far Ultraviolet Spectroscopic Explorer (FUSE) and Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) spectra of 5 dwarf novae above and below the period gap during quiescence.…

Astrophysics · Physics 2009-11-13 P. Godon , E. M. Sion , P. E. Barrett , I. Hubeny , A. P. Linnell , P. Szkody

The UV spectra of nova-like variables are dominated by emission from the accretion disk, modified by scattering in a wind emanating from the disk. Here we model the spectra of RW Tri and UX UMa, the only two eclipsing nova-likes which have…

Solar and Stellar Astrophysics · Physics 2010-08-11 Ulrich M. Noebauer , Knox S. Long , Stuart A. Sim , Christian Knigge

Chemical abundances studies of cataclysmic variables have revealed high nitrogen to carbon ratios in a number of of cataclysmic variable white dwarfs (based on ultraviolet emission and absorption lines), as well as possible carbon…

Solar and Stellar Astrophysics · Physics 2021-03-03 Patrick Godon , Edward Sion

We present an analysis of the Far Ultraviolet Spectroscopic Explorer ({\it{FUSE}}) spectra of the little-known southern nova-like BB Doradus. The spectrum was obtained as part of our Cycle 8 {\it FUSE} survey of high declination nova-like…

Astrophysics · Physics 2009-11-13 P. Godon , E. M. Sion , P. E. Barrett , P. Szkody , E. M. Schlegel

Multiband photometric investigations for eight binary systems of the W Ursae Majoris (W UMa)-type are presented. Six systems are presented for the first time to analyze their light curves. All the analyzed systems have a temperature below…

Solar and Stellar Astrophysics · Physics 2024-01-19 Atila Poro , Mehmet Tanriver , Raul Michel , Ehsan Paki

We present multi-color light curves for the W UMa-type eclipsing binary TU Boo for two epochs separated by 22 years. An analysis of the O-C diagram indicates the earlier observations took place right in the middle of a major period change,…

Astrophysics · Physics 2009-11-13 Jeffrey L. Coughlin , Horace A. Dale , Richard M. Williamon

We obtained Hubble STIS spectra of three nova-like variables: V751 Cygni, V380 Oph, and - the only confirmed nova-like variable known to be below the period gap - BK Lyn. In all three systems, the spectra were taken during high optical…

Solar and Stellar Astrophysics · Physics 2015-05-13 Robert Zellem , Nicholas Hollon , Ronald-Louis Ballouz , Edward M. Sion , Patrick Godon , Boris T. Gänsicke , Knox Long

The spectra arising from the disks of nova-like variables show many of the features seen in stellar atmospheres. They are typically modelled either from an appropriated weighted set of stellar atmospheres or a disk atmosphere with energy is…

Solar and Stellar Astrophysics · Physics 2021-03-31 Ivan Hubeny , Knox S. Long

X-ray dim isolated neutron stars (XDINSs) are characterized by Planckian spectra in X-ray bands, but show optical/ultraviolet(UV) excesses which are the measured photometry exceeding that is extrapolated from X-ray spectra. To solve this…

High Energy Astrophysical Phenomena · Physics 2017-03-15 Weiyang Wang , Jiguang Lu , Hao Tong , Mingyu Ge , Zhaosheng Li , Yunpeng Men , Renxin Xu

We have computed models for ultraluminous X-ray sources ("ULXs") consisting of a black-hole accretor of intermediate mass ("IMBH"; e.g., ~1000 Msun) and a captured donor star. For each of four different sets of initial donor masses and…

Astrophysics · Physics 2009-11-13 N. Madhusudhan , S. Justham , L. Nelson , B. Paxton , E. Pfahl , Ph. Podsiadlowski , S. Rappaport

We compile optical and UV spectra of a sample of 'typical' short period black hole X-ray transients in outburst. We also survey determinations of interstellar extinction and distance in order to deredden spectra and compare absolute fluxes.…

Astrophysics · Physics 2009-11-10 R. I. Hynes

We report photometric and spectroscopic observations of the SU UMa-type dwarf novae, KS Ursae Majoris, during its 2003 February superoutburst. Modulations with a period of $0.07017\pm0.00021$ day, which is 3.3% larger than the orbital…

Astrophysics · Physics 2008-11-26 Yinghe Zhao , Zongyun Li , Xiaoan Wu , Qiuhe Peng , Zhousheng Shang , Zili Li

We present an analysis of the first far-ultraviolet observations of the SW Sextantis-type cataclysmic variable DW Ursae Majoris, obtained in November 2001 with the Far Ultraviolet Spectroscopic Explorer. The time-averaged spectrum of DW UMa…

Astrophysics · Physics 2009-11-10 D. W. Hoard , Paula Szkody , Cynthia S. Froning , Knox S. Long , Christian Knigge

[abridged abstract] Low amplitude (~=0.5%) 29-s oscillations have been detected in HST/FOS eclipse observations of the nova-like cataclysmic variable UX UMa. These are the same dwarf nova-type oscillations that were originally discovered in…

Astrophysics · Physics 2009-10-30 C. Knigge , N. Drake , K. S. Long , R. A. Wade , K. Horne , R. Baptista

We model the multiwavelength properties of binaries accreting at super-critical rates with the aim to better understand the observational properties of Ultra-luminous X-ray Sources (ULXs). We calculate an extended grid of binary systems…

High Energy Astrophysical Phenomena · Physics 2021-11-17 Elena Ambrosi , Luca Zampieri , Fabio Pintore , Anna Wolter

We present an analysis of the FUSE spectra of eight high-declination dwarf novae obtained from a Cycle 7 FUSE survey. These DN systems have not been previously studied in the UV and little is known about their white dwarfs (WDs) or…

Solar and Stellar Astrophysics · Physics 2009-08-05 P. Godon , E. M. Sion , P. E. Barrett , P. Szkody

We present the ultraviolet spectrum of the SW Sex star and nova-like variable DW UMa in an optical low state, as observed with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope (HST). The data are well described…

Astrophysics · Physics 2009-10-31 C. Knigge , K. S. Long , D. W. Hoard , P. Szkody , V. S. Dhillon

Classical supersoft X-ray sources (SSSs) are understood as close binary systems in which a massive white dwarf (WD) accretes from its companion at rates sustaining steady hydrogen burning on its surface generating bolometric luminosities of…

High Energy Astrophysical Phenomena · Physics 2022-09-28 Augustin Skopal