From outburst to quiescence: spectroscopic evolution of V1838 Aql imbedded in a bow-shock nebula

Abstract

We analyse new optical spectroscopic, direct-image and X-ray observations of the recently discovered a high proper motion cataclysmic variable V1838 Aql. The data were obtained during its 2013 superoutburst and its subsequent quiescent state. An extended emission around the source was observed up to 30 days after the peak of the superoutburst, interpreted it as a bow--shock formed by a quasi-continuous outflow from the source in quiescence. The head of the bow--shock is coincident with the high--proper motion vector of the source ($v_{\perp }=123\pm 5$ km s${}^{-1}$) at a distance of $d=202\pm 7$ pc. The object was detected as a weak X-ray source ($0.015\pm 0.002$ counts s${}^{-1}$) in the plateau of the superoutburst, and its flux lowered by two times in quiescence (0.007$\pm$0.002 counts s${}^{-1}$). Spectroscopic observations in quiescence we confirmed the orbital period value $P_{\mathrm{orb}}=0.0545\pm 0.0026$ days, consistent with early-superhump estimates, and the following orbital parameters: $\gamma =-21\pm 3$ km s${}^{-1}$ and $K_1=53\pm 3$ km s${}^{-1}$. The white dwarf is revealed as the system approaches quiescence, which enables us to infer the effective temperature of the primary $T_{eff}=11,600\pm 400$K. The donor temperature is estimated $\lesssim 2200$K and suggestive of a system approaching the period minimum. Doppler maps in quiescence show the presence of the hot spot in HeI line at the expected accretion disc-stream shock position and an unusual structure of the accretion disc in H$\alpha$.

arXiv comment14 pages, 8 figures, accepted manuscript to MNRAS

References in corpus (14)

• SDSS unveils a population of intrinsically faint cataclysmic variables at the minimum orbital period
• Brown Dwarfs and the Cataclysmic Variable Period Minimum
• Population Synthesis of Cataclysmic Variables: I. Inclusion of Detailed Nuclear Evolution
• Effective Temperatures of Cataclysmic Variable White Dwarfs as a Probe of their Evolution
• Shocks in nova outflows. I. Thermal emission
• A brown dwarf mass donor in an accreting binary
• A brief introductory guide to TLUSTY and SYNSPEC
• X-ray Luminosities of Optically-Selected Cataclysmic Variables and Application to the Galactic Ridge X-ray Emission
• An irradiated brown-dwarf companion to an accreting white dwarf
• The remarkable outburst of the highly evolved post-period-minimum dwarf nova SSS J122221.7-311525
• Two new accreting, pulsating white dwarfs: SDSS J1457+51 and BW Sculptoris
• BF Eridani: a cataclysmic variable with a massive white dwarf and an evolved secondary
• Bow-shock Pulsar Wind Nebulae Passing Through Density Discontinuities
• Doppler Tomography and Photometry of the Cataclysmic Variable 1RXS J064434.5+334451

Cited by in corpus (2)

• Bow-shocks, nova shells, disc winds and tilted discs: The Nova-Like V341 Ara Has It All
• A systematic study of spiral density waves in the accretion discs of Cataclysmic Variables