Phase Coherent Timing of RX J0806.3+1527 with ROSAT and CHANDRA

Abstract

RX J0806.3+1527 is an ultra-compact, double degenerate binary with the shortest known orbital period (321.5 s). Hakala et al. (2003) have recently reported new optical measurements of the orbital frequency of the source which indicate that the frequency has increased over the ~9 years since the earliest ROSAT observations. They find two candidate solutions for the long term change in the frequency; df/dt = 3 or 6 x 10E-16 Hz/s. Here we present the results of a phase coherent timing study of the archival ROSAT and Chandra data for RX J0806.3+1527 in the light of these new constraints. We find that the ROSAT -- Chandra timing data are consistent with both of the solutions reported by Hakala et al., but that the higher df/dt = 6.1 x 10E-16 Hz/s solution is favored at the ~97 % level. Such a large df/dt can be accomodated by an ~1 Msun detached double degenerate system powered in the X-ray by electrical energy (Wu et al. 2002). With such a large df/dt the system provides a unique opportunity to explore the interaction of gravitational radiation and electromagnetic torques on the evolution of an ultracompact binary.

AASTeX preprint, 13 pages, 3 Figures. Accepted for Publication in the Astrophysical Journal Letters

References in corpus (1)

• Unveiling the Nature of the 321 s Modulation in RX J0806.3+1527: Near-Simultaneous Chandra and VLT Observations

Cited by in corpus (15)

• Mass Transfer between Double White Dwarfs
• Spectroscopic Evidence for a 5.4-Minute Orbital Period in HM Cancri
• Precision X-ray Timing of RX J0806.3+1527 with CHANDRA: Evidence for Gravitational Radiation from an Ultracompact Binary
• CHANDRA Observations of V407 Vul: Confirmation of the Spin-up
• ULTRACAM Photometry of the ultracompact binaries V407 Vul and HM Cnc
• XMM-Newton observations of the ultra-compact binary RX J1914+24
• Unveiling the Nature of the 321 s Modulation in RX J0806.3+1527: Near-Simultaneous Chandra and VLT Observations
• The Turn-On of Mass Transfer in AM CVn Binaries: Implications for RX J0806+1527 and RX J1914+2456
• Period Changes in Ultra-compact Double White Dwarfs
• Geometrical constraints upon the unipolar model of V407 Vul and RXJ0806.3+1527
• CHANDRA Detection of the AM CVn binary ES Cet (KUV 01584-0939)
• Swift X-ray and ultraviolet observations of the shortest orbital period double-degenerate system RX J0806.3+1527 (HM Cnc)
• Synthetic Direct Impact Light Curves of the Ultracompact AM CVn Binary Systems V407 Vul and HM Cnc
• Magnetic Interaction in Ultra-compact Binary Systems
• Broad Observational Perspectives Achieved by the Accreting White Dwarf Sciences in the XMM-Newton and Chandra Eras