arXiv subjects

E. Mason

Publications and source records attributed to E. Mason.

57 records · Page 4Linked to original sources

arXiv2002

Time-resolved, multi-color photometry and spectroscopy of Virgo 4 (OU Vir): a high orbital inclination, short orbital period dwarf nova

We present multi-color photometry and time resolved spectroscopy of OU Vir. The analysis of the quiescent light curve shows that OU Vir is characterized by i) strong cycle-to-cycle brightness variations, and ii) hot spot modulated light curve with grazing eclipse of the impact region. Colors are derived both in- and out- of eclipse. The time-resolved spectroscopy allows us to produce the radial velocity curve from the H$α$ accretion disk emission line which possibly reveals only weak evidence for hot spot line emission. The hot spot is believed to be a turbulent optically thick region, producing mostly continuum emission.

astro-ph↗

arXiv2001

High spectral resolution time-resolved optical spectroscopy of V893 Sco

We present high resolution time-resolved optical spectra of the high inclination short orbital period dwarf nova V893 Sco. We performed spectral analysis through radial velocity measurements, Doppler mapping, and ratioed Doppler maps. Our results indicate that V893 Sco's accretion disk is dissimilar to WZ Sge's accretion disk, and does not fit any of the current accretion disk models. We derive the system parameters M1 and i, and present evidence for V893 Sco as a very young cataclysmic variable and an ER UMa star. We advance the hypothesis that all ER UMa stars may be newly formed cataclysmic variables.

astro-ph↗

arXiv2000

Investigating the structure of the accretion disk in WZ Sge from multi-wave-band, time-resolved spectroscopic observations: Paper II

We present our second paper describing multi-wave-band, time-resolved spectroscopy of WZ Sge. We analyze the evolution of both optical and IR emission lines throughout the orbital period and find evidence, in the Balmer lines, for an optically thin accretion disk and an optically thick hot-spot. Optical and IR emission lines are used to compute radial velocity curves. Fits to our radial velocity measurements give an internally inconsistent set of values for K1, gamma, and the phase of red-to-blue crossing. We present a probable explanation for these discrepancies and provide evidence for similar behaviour in other short orbital period dwarf-novae. Selected optical and IR spectra are measured to determine the accretion disk radii. Values for the disk radii are found to be strongly dependent on the assumed WD mass and binary orbital inclination. However, the separation of the peaks in the optical emission line (i.e. an indication of the outer disk radius) has been found to be constant during all phases of the super-cycle period over the last 40 years.

astro-ph↗