Infrared spectroscopy of cataclysmic variables -- III. Dwarf novae below the period gap and nova-like variables

Dhillon, V. S.; Littlefair, S. P.; Howell, Steve B.; Ciardi, David R.; Harrop-Allin, M. K.; Marsh, T. R.

doi:10.1046/j.1365-8711.2000.03427.x

Cited by 41 publications

(24 citation statements)

References 36 publications

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“…This situation is exacerbated among the NLs, in which the generally high mass transfer rates produce prominent disks that can dominate the SEDs over a wide range of wavelengths. Dhillon et al (2000) found that in a sample of six bright NLs (including RW Tri and VY Scl), none show evidence of the secondary star in their K-band spectra. Nonetheless, we must consider that the secondary star could make a nonnegligible contribution to the observed near-IR SED for some of our targets, which would produce disagreement with the Frank et al ( 2002) model accretion disk spectrum.…”

Section: Infrared Excessmentioning

confidence: 96%

Nova-Like Cataclysmic Variables in the Infrared

Hoard

Long

Howell

et al. 2014

ApJ

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Nova-like (NL) cataclysmic variables have persistently high mass transfer rates and prominent steady state accretion disks. We present an analysis of infrared observations of 12 NLs obtained from the Two Micron All Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer All Sky Survey. The presence of an infrared excess at λ 3-5 μm over the expectation of a theoretical steady state accretion disk is ubiquitous in our sample. The strength of the infrared excess is not correlated with orbital period, but shows a statistically significant correlation (but shallow trend) with system inclination that might be partially (but not completely) linked to the increasing view of the cooler outer accretion disk and disk rim at higher inclinations. We discuss the possible origin of the infrared excess in terms of emission from bremsstrahlung or circumbinary dust, with either mechanism facilitated by the mass outflows (e.g., disk wind/corona, accretion stream overflow, and so on) present in NLs. Our comparison of the relative advantages and disadvantages of either mechanism for explaining the observations suggests that the situation is rather ambiguous, largely circumstantial, and in need of stricter observational constraints.

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Section: Infrared Excessmentioning

confidence: 96%

Nova-Like Cataclysmic Variables in the Infrared

Hoard

Long

Howell

et al. 2014

ApJ

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“…In quiescence such P Cyg profiles are not generally seen (see e.g. the DN sample observed by Dhillon et al 2000). It is possible that the 2019 eruption has generated two separate outflows, as witnessed in the July 1 profile of the singlet line.…”

Section: The Infrared Spectramentioning

confidence: 97%

Infrared Spectroscopy of the Recent Outburst in V1047 Cen (Nova Centauri 2005)

Geballe

Banerjee

Evans

et al. 2019

ApJL

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Fourteen years after its eruption as a classical nova (CN), V1047 Cen (Nova Cen 2005) began an unusual re-brightening in 2019 April. The amplitude of the brightening suggests that this is a dwarf nova (DN) eruption in a CN system. Very few CNe have had DN eruptions within decades of the main CN outburst. The 14 years separating the CN and DN eruptions of V1047 Cen is the shortest of all instances recorded thus far. Explaining this rapid succession of CN and DN outbursts in V1047 Cen may be challenging within the framework of standard theories for DN outbursts. Following a CN eruption, the mass accretion rate is believed to remain high (Ṁ ∼ 10 −8 M ⊙ yr −1 ) for a few centuries, due to the irradiation of the secondary star by the still-hot surface of the white dwarf. Thus a DN eruption is not expected to occur during this high mass accretion phase as DN outbursts, which result from thermal instabilities in the accretion disk, and arise during a regime of low mass accretion rate (Ṁ ∼ 10 −10 M ⊙ yr −1 ). Here we present near-infrared spectroscopy to show that the present outburst is most likely a DN eruption, and discuss the possible reasons for its early occurrence. Even if the present re-brightening is later shown to be due to a cause other than a DN outburst, the present study provides invaluable documentation of this unusual event.

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“…The observations and reduction of the J ‐ and K ‐band infrared data are described in Littlefair et al (2000) and Dhillon et al (2000) respectively. The J ‐ and K ‐band time‐averaged spectra are shown in Fig.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Investigating the structure of the accretion disc in WZ Sge from multiwaveband time-resolved spectroscopic observations — I

Skidmore¹,

Mason²,

Howell³

et al. 2000

Monthly Notices of the Royal Astronomical Society

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We present the first of two papers describing an in-depth study of multiwaveband phaseresolved spectroscopy of the unusual dwarf nova WZ Sge. In this paper we present an extensive set of Doppler maps of WZ Sge covering optical and infrared emission lines, and describe a new technique for studying the accretion discs of cataclysmic variables using ratioed Doppler maps. Applying the ratioed Doppler map technique to our WZ Sge data shows that the radial temperature profile of the disc is unlike that predicted for a steady state a disc. Time-averaged spectra of the accretion disc line flux (with the bright spot contribution removed) show evidence in the shapes of the line profiles for the presence of shear broadening in a quiescent non-turbulent accretion disc. From the positions of the bright spots in the Doppler maps of different lines, we conclude that the bright spot region is elongated along the ballistic stream, and that the density of the outer disc is low. The velocity of the outer edge of the accretion disc measured from the Ha line is found to be 723^23 km s 21 X Assuming that the accretion disc reaches to the 3:1 tidal resonance radius, we derive a value for the primary star mass of 0.82 M ( . We discuss the implications of our results on the present theories of WZ Sge type dwarf nova outbursts.

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Infrared spectroscopy of cataclysmic variables -- III. Dwarf novae below the period gap and nova-like variables

Cited by 41 publications

References 36 publications

Nova-Like Cataclysmic Variables in the Infrared

Nova-Like Cataclysmic Variables in the Infrared

Infrared Spectroscopy of the Recent Outburst in V1047 Cen (Nova Centauri 2005)

Investigating the structure of the accretion disc in WZ Sge from multiwaveband time-resolved spectroscopic observations — I

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