RXTE and<i>XMM</i>observations of intermediate polar candidates

Butters, O. W.; Norton, A. J.; Mukai, K.; Tomsick, John A.

doi:10.1051/0004-6361/201015848

Cited by 17 publications

(16 citation statements)

References 30 publications

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“…These show that, whilst the properties of the continuum are consistent with those seen for other IPs, the inferred EQWs of the iron lines are towards the upper limit of what has previously been observed (e.g. Butters et al 2011). We note that due to the marginal improvement in fit quality from including three Gaussians over a single component, obtaining constraining estimates for the errors on the strength (EQW) and breadth (σ) is unrealistic and so are omitted.…”

Section: X‐ray Spectral Analysissupporting

confidence: 85%

Identifying a new intermediate polar using XMM-Newton and INTEGRAL

Middleton¹,

Cackett²,

Shaw³

et al. 2011

Monthly Notices of the Royal Astronomical Society

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The bright X-ray source 2XMMi J180438.7−145647 is fortunate to have long baseline observations in INTEGRAL that complement observations taken by other missions. Optical spectroscopy of this object has suggested a distance of ∼7 kpc and an identification with a low-mass X-ray binary. We instead use the X-ray data from 0.3 to 40 keV to identify the source as a bright intermediate polar (IP) with an estimate for the white dwarf mass of ∼0.60 M . This identification is supported by the presence of an iron triplet, the component lines of which are some of the strongest seen in IPs, and the signature of the spin period of the white dwarf at ∼24 min. We note that the lack of broad-band variability may suggest that this object is a stream-fed IP, similar in many respects to the well-studied IP, V2400 Oph. Phase binning has allowed us to create spectra corresponding to the peaks and troughs of the light curve from which we determine that the spectra appear harder in the troughs, consistent with the behaviour of other IPs binned on their spin periods. This work strongly suggests a misidentification in the optical due to the presence of large columns of enshrouding material. We instead propose a distance to the source of <2.5 kpc to be consistent with the luminosities of other IPs in the dim, hard state. The considerable flux of the source together with the strength of the iron lines may, in future, allow the source to be used to diagnose the properties of the shock-heated plasma and the reflected component of the emission.

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Section: X‐ray Spectral Analysissupporting

confidence: 85%

Identifying a new intermediate polar using XMM-Newton and INTEGRAL

Middleton¹,

Cackett²,

Shaw³

et al. 2011

Monthly Notices of the Royal Astronomical Society

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“…Only 14 years later de Martino et al (2009) proved that this assumption is correct due to detection of the oscillation with a period of 743.2 ± 0.4 s, which was observed both in X-rays and in optical light. Shortly afterwards this oscillation was independently confirmed both in X-rays (743.2 ± 0.9 s, Butters et al 2011;743.1 ± 0.6 s, Bernardini et al 2012) and in optical light (743.38 ± 0.25 s, Nasiroglu et al 2012). Thus, because all short periods measured by different authors are compatible with each other, the IP nature of V2069 Cyg seems undoubted.…”

Section: Introductionmentioning

confidence: 75%

Extensive photometry of the intermediate polar V2069 Cyg (RX J2123.7+4217)

Kozhevnikov

2017

Astrophys Space Sci

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To obtain the spin period of the white dwarf in the intermediate polar V2069 Cyg with high precision, we fulfilled extensive photometry. Observations were performed within 32 nights, which have a total duration of 119 hours and cover 15 months. We found the spin period of the white dwarf, which is equal to 743.406 50 ± 0.000 48 s. Using our precise spin period, we derived the oscillation ephemeris with a long validity of 36 years. This ephemeris and the precise spin period can be used for future investigations of spin period changes of the white dwarf in V2069 Cyg. In addition, for the first time we detected the sideband oscillation with a period of 764.5125 ± 0.0049 s. The spin and sideband oscillations revealed unstable amplitudes both in a time-scale of days and in a time-scale of years. On average, the semi-amplitude of the spin oscillation varied from 17 mmag in 2014 to 25 mmag in 2015. The semi-amplitude of the sideband oscillation varied from 12 mmag in 2014 to an undetectable level of less than 7 mmag in 2015. In a time-scale of years, the optical spin pulse profile revealed essential changes from an asymmetric double-peaked shape in 2014 to a quasi-sinusoidal shape in 2015. Such drastic changes of the optical spin pulse profile seem untypical of most intermediate polars and, therefore, are of great interest. The pulse profile of the sideband oscillation was quasi-sinusoidal. Moreover, we note that V2069 Cyg possesses strong flickering with a peak-to-peak amplitude of 0.4-0.6 mag.

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“…In fact, INTE-GRAL/IBIS has discovered many CVs of the intermediate polar sub-class; these are brighter in hard X-rays than the CVs of the polar sub-class (see section 1), since the plasma is hotter (it is less cooled by synchrotron emission than in the polars, because the magnetic field is less strong). V2487 Oph was also detected with RXTE/PCA, showing characteristics of an intermediate polar [3]. All these observations indicate that the WD in this nova should be massive and magnetic, although the expected temporal variabilities have not been seen.…”

Section: X-ray Observationsmentioning

confidence: 79%

V2487 Oph 1998: a post nova in an intermediate polar

Hernanz

2014

EPJ Web of Conferences

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Abstract. V2487 Oph (Nova Oph 1998) is a classical nova that exploded in 1998. XMM-Newton observations performed between 2 and 9 years after the explosion showed emission related to restablished accretion, and indicative of a magnetic white dwarf. The spectrum looks like that of a cataclysmic variable of the intermediate polar type. Anyway, we don't have yet a definitive confirmation of the intermediate polar character, through determination of spin and orbital periods. Although it is not the first nova exploding in a magnetic white dwarf, it is always challenging to reach explosive conditions when a standard accretion disk can't be formed, because of the magnetic field. In addition, V2487 Oph has been the first nova where a detection of X-rays -in the host binary system -has been reported prior to its eruption, in 1990 with the ROSAT satellite. V2487 Oph has been also detected in hard X-rays with INTEGRAL/IBIS and RXTE/PCA. Last but not least, V2487 Oph has been identified as a recurrent nova in 2008, since a prior eruption in 1900 has been reported through analysis of Harvard photographic plates. Therefore, it is expected to host a massive white dwarf and be a candidate for a type Ia supernova explosion. In a recent study of the progenitors of galactic novae, it has been emphasized that V2487 Oph is an important and interesting object, "intermediate" between the "standard" classical novae and other historical and well-known recurrent novae with shorter recurrence periods. It could be that in the end there's a continuous distribution of recurrence periods, instead of the common understanding up to now that "classical" and "recurrent" novae were quite apart (with recurrence periods of more than 10 4 years and less than 100 years -approximately -respectively). We present the results of our campaign of several observations with XMM-Newton. The consequences for the understanding of such a puzzling object are discussed.

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RXTE andXMMobservations of intermediate polar candidates

Cited by 17 publications

References 30 publications

Identifying a new intermediate polar using XMM-Newton and INTEGRAL

Identifying a new intermediate polar using XMM-Newton and INTEGRAL

Extensive photometry of the intermediate polar V2069 Cyg (RX J2123.7+4217)

V2487 Oph 1998: a post nova in an intermediate polar

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