Ultraviolet Spectral Behavior of UX Ari with Periodic Flaring Activity

Autor:	I. Zead, M. A. Abdel-Sabour, M. R. Sanad
Rok vydání:	2021
Předmět:	Physics Wavelength medicine Astronomy and Astrophysics Astrophysics Emission spectrum medicine.disease_cause Absorption (electromagnetic radiation) Chromosphere Ultraviolet Spectral line Line (formation) Luminosity
Zdroj:	Astrophysics. 64:316-326
ISSN:	1573-8191 0571-7256
Popis:	We present International Ultraviolet Explorer (IUE) observations of the luminous, non- eclipsing, double lined spectroscopic binary system UX Ari over the period 1978-1996. Three spectra showing modulations in line fluxes at different times are presented. The ultraviolet spectra reveal emission lines originating in the chromosphere and transition region of the primary star. UX Ari has a periodic flaring activity in different wavelength bands each 7-9 years. The reddening of UX Ari determined from 2200 A absorption feature to be E(B - V) = 0.14 ± 0.02. The calculated fluxes of CII 1335 A , CIV 1550 A & HeII 1640 A emission lines showed a correlation with the orbital phase. The results confirmed that magnetic activity is the source and reason for emission lines and their changes. We determined the mass loss rate to be 10–6 M⨀ yr-1, the temperature of the emitting region is 104 K ± 220 K, and the ultraviolet luminosity is 8·1029 erg s-1. The results agree with the inhomogeneous gyro-synchrotron model.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::99d21ec3b3227b2f88fcf7e739255fb1 https://doi.org/10.1007/s10511-021-09692-1 Zobrazit plný text záznamu Plný text ve formátu PDF