arXiv subjects

Zwidofhela N. Khangale

Publications and source records attributed to Zwidofhela N. Khangale.

2 recordsLinked to original sources

arXiv2026

Discovery of a radio-flaring M dwarf in a commensal transient search of the LADUMA field

We report the discovery and characterisation of MKT J032848.4-271904.6, a new radio transient identified in the LADUMA field using SARAO Science Data Processor (SDP) UHF-band images from approximately one year of MeerKAT observations. Using the Transient Pipeline (TraP) and advanced filtering techniques, we identified a number of candidate variable radio sources in the field. All but one show variability consistent with refractive interstellar scintillation, leaving MKT J032848.4-271904.6 as the sole source exhibiting intrinsic variability. In addition, MKT J032848.4-271904.6 shows intrinsic variability at 0.816 GHz, with 13 radio detections across 41 epochs and a peak flux density of 1.041+/-0.043 mJy. We associate this emission with a low-mass M-dwarf star LP 888-63, located 23 pc from the Sun and identified as a companion to the white dwarf binary system LAWD 14 / WD 0326-273. LP 888-63 displays active flaring behaviour across the electromagnetic spectrum, including multi-band optical data from MeerLICHT. TESS photometry reveals a periodic modulation in the blended light curve of 5.780+/-0.507 days, consistent with rotational variability of a mid-M dwarf. Archival ESO spectra reveal Halpha emission, confirming magnetic activity. These findings highlight the capability of MeerKAT's SDP imaging and facilities like MeerLICHT for real-time detection and characterisation of stellar transients.

astro-ph.SR↗

arXiv2025

Phase-resolved spectroscopic observations of the magnetic cataclysmic binary EF Eridani: Revealing complex magnetic accretion during a high state

We present high-resolution, phase-resolved spectroscopic observations of the polar EF Eri, obtained with SALT and the SAAO 1.9-m telescope during its recent emergence from a three-decade-long low state. The average spectrum shows strong emission from the Balmer lines (H$α$ and H$β$) and He~\textsc{ii} 4686 Å, along with weaker emission from the He~\textsc{i} lines and the Bowen fluorescence (C~\textsc{iii}/N~\textsc{iii}) blend at 4650 Å. The emission lines redward of 5500 Å transition to pure absorption at orbital phases $\sim$0.75--0.95, which we attribute to obscuration of the line-emitting region by the accretion stream. Trailed spectra of the emission lines reveal multicomponent structures consistent with other polars. In this first Doppler study of EF Eri, tomograms of the strongest lines (He~\textsc{ii} 4686 Å and the Balmer lines), using both the standard and inside-out projections, identify three key emission regions: the irradiated face of the secondary star, the ballistic and threading regions of the accretion stream, and the magnetically confined flow. Our Doppler maps show not only the ballistic stream but also two unambiguous magnetic accretion flows, which is consistent with the presence of multiple magnetic accretion regions.

astro-ph.SR↗