2020/05/07 by K. A. Stoyanov, K. Iłkiewicz, Krystian Iłkiewicz +9
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Emission spectrum #Galaxy #Luminosity #Optics #Physics #Spectral line #Spectroscopy #Stellar, planetary, and galactic studies #Symbiotic star #Telescope #Ultraviolet #astro-ph.SR
paper · pdf · doi:10.1093/mnras/staa1310
Accepted for publication in MNRAS
arxiv created 2020/05/07 · openalex publication_date 2020/05/11 · openalex created_date 2020/05/13 · arxiv updated 2020/05/20 · openalex updated_date 2026/08/06
ABSTRACT We performed high-resolution optical spectroscopy and X-ray observations of the recently identified Mira-type symbiotic star EF Aql. Based on high-resolution optical spectroscopy obtained with the Southern African Large Telescope (SALT), we determine the temperature (∼55 000 K) and the luminosity (∼5.3 L⊙) of the hot component in the system. The heliocentric radial velocities of the emission lines in the spectra reveal possible stratification of the chemical elements. We also estimate the mass-loss rate of the Mira donor star. Our Swift observation did not detect EF Aql in X-rays. The upper limit of the X-ray observations is 10−12 erg cm−2 s−1, which means that EF Aql is consistent with the faintest X-ray systems detected so far. Otherwise we detected it with the UltraViolet and Optical Telescope (UVOT) instrument with an average UVM2 magnitude of 14.05. During the exposure, EF Aql became approximately 0.2 UVM2 magnitudes fainter. The periodogram analysis of the V-band data reveals an improved period of 320.4 ± 0.3 d caused by the pulsations of the Mira-type donor star.