A Method for the Study of Accretion Disk Emission in Cataclysmic Variables. I. The Model

Puebla, R. E.; Diaz, Marcos P.; Hillier, D. J.; Hubený, I.

doi:10.1088/0004-637x/736/1/17

Cited by 21 publications

(23 citation statements)

References 76 publications

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“…Considerable effort has been spent over the years on understanding and modelling these UV features (e.g. Drew & Verbunt 1985;Mauche & Raymond 1987;Drew 1987;Shlosman & Vitello 1993;[hereafter SV93]; Knigge, Woods & Drew 1995;Knigge & Drew 1997;Long & Knigge 2002 [hereafter LK02], Noebauer et al 2010;Puebla et al 2011). The basic picture emerging from these efforts is of a slowly accelerating, moderately collimated bipolar outflow that carries away ≃ 1% − 10% of the accreting material.…”

Section: Introductionmentioning

confidence: 99%

The impact of accretion disc winds on the optical spectra of cataclysmic variables

Matthews¹,

Knigge²,

Long³

et al. 2015

Monthly Notices of the Royal Astronomical Society

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Many high-state non-magnetic cataclysmic variables (CVs) exhibit blue-shifted absorption or P-Cygni profiles associated with ultraviolet (UV) resonance lines. These features imply the existence of powerful accretion disk winds in CVs. Here, we use our Monte Carlo ionization and radiative transfer code to investigate whether disk wind models that produce realistic UV line profiles are also likely to generate observationally significant recombination line and continuum emission in the optical waveband. We also test whether outflows may be responsible for the single-peaked emission line profiles often seen in high-state CVs and for the weakness of the Balmer absorption edge (relative to simple models of optically thick accretion disks). We find that a standard disk wind model that is successful in reproducing the UV spectra of CVs also leaves a noticeable imprint on the optical spectrum, particularly for systems viewed at high inclination. The strongest optical wind-formed recombination lines are Hα and He ii λ4686. We demonstrate that a higher-density outflow model produces all the expected H and He lines and produces a recombination continuum that can fill in the Balmer jump at high inclinations. This model displays reasonable verisimilitude with the optical spectrum of RW Trianguli. No single-peaked emission is seen, although we observe a narrowing of the double-peaked emission lines from the base of the wind. Finally, we show that even denser models can produce a single-peaked Hα line. On the basis of our results, we suggest that winds can modify, and perhaps even dominate, the line and continuum emission from CVs.

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Section: Introductionmentioning

confidence: 99%

The impact of accretion disc winds on the optical spectra of cataclysmic variables

Matthews¹,

Knigge²,

Long³

et al. 2015

Monthly Notices of the Royal Astronomical Society

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“…In this respect it is worth pointing out that, in contrast to the large number of UV (mostly IUE) and far-UV (mostly FUSE) studies for other classes of CVs (see, for example, Verbunt & Wade 1984;La Dous 1991;Mauche et al 1997;Araujo-Betancor et al 2005;Long 2006; Gänsicke et al 2006;Hamilton et al 2007;Sion et al 2008;Froning et al 2012), in the case of old novae, A&A 560, A49 (2013) the studies have been fairly preliminary (Gilmozzi et al 1994;Selvelli 2004) or limited to a subset of objects (Szkody et al 1991;Puebla et al 2007Puebla et al , 2011.…”

Section: Introductionmentioning

confidence: 99%

An archive study of 18 old novae

Selvelli

Gilmozzi

2013

A&A

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Aims. We present an overview of the UV spectral properties of old novae as a class. The data and results of this paper, together with data from the outburst phases, will be utilized in a follow-up study to determine statistical properties and to investigate correlations among the physical parameters of the quiescent and eruptive phases. Methods. All the available IUE, HST, and FUSE archive data for 18 old novae were used to derive accurate and homogeneous estimates of the reddening from the 2175 Å extinction bump and to determine the intrinsic spectral energy distribution corresponding to the utilization of both existing extinction curves. We also measured all the emission and absorption lines. Results. We have found good agreement between spectra taken at different epochs and by different instruments, a clear indication of the near constancy of the SED on timescales of several years. With the possible exception of GK Per, the dereddened UV continua are represented well by a single-curve power-law distribution F λ ∝ λ −α , with α in the range 0.32-2.55 for one curve and 0.35-2.88 for the other one. The extrapolation of the various UV power laws to the optical range yields values that are in good agreement with the V magnitudes. We interpret this result as evidence that the SED is dominated by the accretion disk in the UV and optical spectral regions. A detailed study of the emission spectrum has led to measuring and identifying more than one hundred features and to detecting several lines that are rather uncommon in other CVs and whose identification is uncertain.

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“…Compared with these works, our approach is simpler in that we assume a constant wind temperature as a given parameter as well as pure LTE. Recently, Puebla et al (2011) investigated accretion-disk emission in CVs, calculating 1D-wind models in the comoving frame and combining these into 2.5D models for which they computed synthetic spectra. In contrast to their work, our wind models are calculated in 2.5 dimensions.…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo radiation transfer in CV disk winds: application to the AM CVn prototype

Kusterer

Nagel

Hartmann

et al. 2013

A&A

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Context. AM CVn systems are ultracompact binaries in which a (semi-) degenerate star transfers helium-dominated matter onto a white dwarf. They are effective gravitational-wave emitters and potential progenitors of Type Ia supernovae. Aims. To understand the evolution of AM CVn systems it is necessary to determine their mass-loss rate through their radiationdriven accretion-disk wind. We constructed models to perform quantitative spectroscopy of P Cygni line profiles that were detected in UV spectra. Methods. We performed 2.5D Monte Carlo radiative transfer calculations in hydrodynamic wind structures by making use of realistic NLTE spectra from the accretion disk and by accounting for the white dwarf as an additional photon source. Results. We present first results from calculations in which LTE opacities are used in the wind model. A comparison with UV spectroscopy of the AM CVn prototype shows that the modeling procedure is potentially a good tool for determining mass-loss rates and abundances of trace metals in the helium-rich wind.

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A Method for the Study of Accretion Disk Emission in Cataclysmic Variables. I. The Model

Cited by 21 publications

References 76 publications

The impact of accretion disc winds on the optical spectra of cataclysmic variables

The impact of accretion disc winds on the optical spectra of cataclysmic variables

An archive study of 18 old novae

Monte Carlo radiation transfer in CV disk winds: application to the AM CVn prototype

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