Open AccessThe accretion flow in the discless intermediate polar V2400 Ophiuchi
Author(s) -
Hellier Coel,
Beardmore A. P.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05199.x
Subject(s) - physics , intermediate polar , white dwarf , astrophysics , accretion (finance) , polar , light curve , diamagnetism , accretion disc , beat (acoustics) , line (geometry) , astronomy , magnetic field , stars , geometry , optics , mathematics , quantum mechanics
RXTE observations confirm that the X‐ray light curve of V2400 Oph is pulsed at the beat cycle, as expected in a discless intermediate polar. There are no X‐ray modulations at the orbital or spin cycles, but optical line profiles vary with all three cycles. We construct a model for line‐profile variations in a discless accretor, based on the idea that the accretion stream flips from one magnetic pole to the other, and show that this accounts for the observed behaviour over the spin and beat cycles. The minimal variability over the orbital cycle implies that (1) V2400 Oph is at an inclination of only ≈10°, and (2) much of the accretion flow is not in a coherent stream, but is circling the white dwarf, possibly as a ring of denser, diamagnetic blobs. We discuss the light that this sheds on disc formation in intermediate polars.