2023/10/11 by Kala G. Pradeep, Pradeep, Kala G., K. P. Singh +17
Engineering · Physics and Astronomy · #Astronomical Observations and Instrumentation #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Demography #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE) #Luminosity #Meteorology #Omega #Outgoing longwave radiation #Physics #Polar #Population #Solar and Stellar Astrophysics (astro-ph.SR) #Stars #White dwarf
paper · pdf · doi:10.48550/arxiv.2310.07293
openalex publication_date 2023/10/11 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present multi-wavelength temporal and spectral characteristics of a magnetic cataclysmic variable (MCV) Swift J0503.7-2819, using far ultraviolet (FUV) and X-ray data from AstroSat, supplemented with optical data from the Southern African Large Telescope and X-ray data from the XMM-Newton and Swift observatories. The X-ray modulations at 4897.6657 s and 3932.0355 s are interpreted as the orbital (PΩ) and spin (Pω) period, respectively, and are consistent with prior reports. With a spin-orbit period ratio of 0.8 and PΩ falling below the period gap (2-3 hrs) of CVs, Swift J0503.7-2819 would be the newest addition to the growing population of nearly synchronous MCVs, which we call EX Hya-like systems. Hard X-ray luminosity of < 2.5×1032 erg s-1, as measured with the Swift Burst Alert Telescope, identifies it to be a low-luminosity intermediate polar, similar to other EX Hya-like systems. The phenomenology of the light curves and the spectral characteristics rule out a purely disc-fed/stream-fed model and instead reveal the presence of complex accretion structures around the white dwarf. We propose a ring-like accretion flow, akin to EX Hya, using period ratio, stability arguments, and observational features. An attempt is made to differentiate between the asynchronous polar/nearly-synchronous intermediate polar nature of Swift J0503.7-2819. Further, we note that with the advent of sensitive surveys, a growing population of MCVs that exhibit characteristics of both polars and intermediate polars is beginning to be identified, likely forming a genealogical link between the two conventional classes of MCVs.