Investigation of EPR signals on tooth enamel

Pavlenko, A.; Миронова-Улмане, Н.; Polakov, M; Riekstina, D.

doi:10.1088/1742-6596/93/1/012047

Cited by 3 publications

(8 citation statements)

References 4 publications

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“…Such a low mass WD is unlikely given that evidence from the nova ejecta (Lance, McCall, and Uomoto 1988) indicate a high mass WD. Photometry over the intervening years indicated that the WD was undergoing fast and nonlinear synchronization from measurements by Katz (1991) with a rate of P = 1.8 × 10 −6 for 1977-1979, 2.7 × 10 −8 for 1979-1987, and 2.4 × 10 −8 for 2000-2003(Pavlenko and Shugarov 2005a. Schmidt, et al (1995) obtained P = 3.86 × 10 −8 for 1987-1992 from polarimetry.…”

Section: Introductionmentioning

confidence: 98%

“…The beat period has systematically increased with time. Using the spin-orbit beat period relation, orbital and beat periods were used for calculation of the current value of the WD spin period (Pavlenko and Shugarov 2005a) rather than direct measurements of the WD spin period which is possible only while the accretion flow is stable, between pole switchings, and is best done with polarimetric or X-ray observations. Spin-orbit synchronization times of a hundreds to a few thousand years are expected from theory, see e.g.…”

Section: Introductionmentioning

confidence: 99%

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Asynchronous polar V1500 Cyg: orbital, spin and beat periods

Павленко

Mason

Sosnovskij³

et al. 2018

Monthly Notices of the Royal Astronomical Society

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The bright Nova Cygni 1975 is a rare nova on a magnetic white dwarf (WD). Later it was found to be an asynchronous polar, now called V1500 Cyg. Our multisite photometric campaign occurring 40 years post eruption covered 26-nights (2015-2017). The reflection effect from the heated donor has decreased, but still dominates the optical radiation with an amplitude ∼ 1 m .5. The 0 m .3 residual reveals cyclotron emission and ellipsoidal variations. Mean brightness modulation from night-to-night is used to measure the 9.6-d spin-orbit beat period that is due to changing accretion geometry including magnetic pole-switching of the flow. By subtracting the orbital and beat frequencies, spin-phase dependent light curves are obtained. The amplitude and profile of the WD spin light curves track the cyclotron emitting accretion regions on the WD and they vary systematically with beat phase. A weak intermittent signal at 0.137613d is likely the spin period, which is 1.73(1) min shorter than the orbital period. The O-C diagram of light curve maxima displays phase jumps every one-half beat period, a characteristic of asynchronous polars. The first jump we interpret as pole switching between regions separated by 180 • . Then the spot drifts during ∼ 0.1 beat phase before undergoing a second phase jump between spots separated by less than 180 • . We trace the cooling of the still hot WD as revealed by the irradiated companion. The post nova evolution and spin-orbit asynchronism of V1500 Cyg continues to be a powerful laboratory for accretion flows onto magnetic white dwarfs.

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Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Asynchronous polar V1500 Cyg: orbital, spin and beat periods

Павленко

Mason

Sosnovskij³

et al. 2018

Monthly Notices of the Royal Astronomical Society

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“…Its 0.060-d superhump period (Pavlenko et al 2007;Kato et al 2011) and 0.059005-d orbital period (Pavlenko 2009;Zharikov et al 2008;Kato et al 2009) suggested SDSS J0804 as a period bouncer, passed the period minimum (Zharikov et al 2008). Pavlenko et al (2007) first discovered the nonradial pulsations of the WD that appeared 8 months after the 2006 outburst and lasted for ∼ 2 years. Now there are thirteen accreting pulsating WDs belonging to the SU UMa stars (Mukadam et al 2010).…”

Section: Introductionmentioning

confidence: 99%

“…SDSS J080434.20+510349.2 (hereafter SDSS J0804) was first discovered as a CV and was considered as a potential dwarf nova with an underlying white dwarf (WD) in quiescence prior to the 2006 outburst (Szkody et al 2006) and it was first found in outburst by (Pavlenko et al 2007). Its 0.060-d superhump period (Pavlenko et al 2007;Kato et al 2011) and 0.059005-d orbital period (Pavlenko 2009;Zharikov et al 2008;Kato et al 2009) suggested SDSS J0804 as a period bouncer, passed the period minimum (Zharikov et al 2008). Pavlenko et al (2007) first discovered the nonradial pulsations of the WD that appeared 8 months after the 2006 outburst and lasted for ∼ 2 years.…”

Section: Introductionmentioning

confidence: 99%

SDSS J080434.20+510349.2: Cataclysmic Variable Witnessing the Instability Strip?

Pavlenko,

Malanushenko,

Tovmassian

et al. 2011

Preprint

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SDSS J080434.20+510349.2 is the 13th dwarf nova containing a pulsating white dwarf. Among the accreting pulsators that have experienced a dwarf novae outburst, SDSS J0804 has the most dramatic history of events within a short time scale: the 2006 outburst with 11 rebrightenings, series of December 2006 -January 2007 mini-outbursts, the 2010 outburst with 6 rebrightenings. Over 2006-2011, SDSS J080434.20+510349.2 in addition to positive 0.060 d superhumps during the outburst and 1-month post-outburst stage, 0.059005 d orbital humps in quiescence, displayed a significant short-term variations with periods P1 = 12.6 min, P2 = 21.7 min, P3 = 14.1 min and P4 = 4.28 min. The 12.6-min periodicity first appeared 7 months after the 2006 outburst and was the most prominent one during the following ∼ 900 days. It was identified as non-radial pulsations of the white dwarf. The period of this pulsations varied within a range of 36 s, and amplitude changed from 0.013 m to 0.03 m . Simultaneously one could observe the 21.7-min and 14.3-min periodicities with a much lower significance level. During the minioutbursts the 21.7-min periodicity became the most powerful, the 12.6-min periodicity was less powerful, and the 12.6-min periodicity had the lowest significance. After the 2011 outburst the most prominent short-term periodicity appeared ∼ 7 months after the outburst, but at 4.28 min. We identified that variability with periods P2, P3 and P4 could be additional pulsation modes, however the relation of P4 to white dwarf pulsation also can't be excluded.

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“…The signal is predominantly derived from stable CO 2 -radical (IAEA, 2002). Two methods have been used to assess the absorbed dose of irradiated enamel by EPR: additive re-irradiation and the use of calibration curve, in the additive re-irradiation method: the sample is incrementally irradiated to construct a response curve specific to the sample in question (Pavlenko, A et al, 2007) as shown in Figure (8). The other method uses a universal calibration curve (EPR signal Intensity versus absorbed dose) generated using a large blended sample pool of enamel material designed to average the sample-to-sample variances.…”

Section: Retrospective and Emergency Dosimetry 541 Teeth Enamel Dosmentioning

confidence: 99%

Ionizing Radiation Induced Radicals

Maghraby¹

2012

Current Topics in Ionizing Radiation Research

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Investigation of EPR signals on tooth enamel

Cited by 3 publications

References 4 publications

Asynchronous polar V1500 Cyg: orbital, spin and beat periods

Asynchronous polar V1500 Cyg: orbital, spin and beat periods

SDSS J080434.20+510349.2: Cataclysmic Variable Witnessing the Instability Strip?

Ionizing Radiation Induced Radicals

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