The High-Energy Transmission Grating spectra show numerous narrow, unresolved (FWHM 200 km s-1) absorption lines from a wide range of ionization states of N, O, Mg, Ne, Si, S, Ar, and Fe. Assuming that accretion powers the X-ray emission, our results for log ne suggest an accretion rate of ~10-8 M☉ yr-1.read more read lessĪbstract: We present detailed evidence for a warm absorber in the Seyfert 1 galaxy MCG -6-30-15 and dispute earlier claims for relativistic O line emission. The inferred plasma temperature distribution and densities are consistent with a model in which the bulk of the X-ray emission from TW Hya is generated via mass accretion from its circumstellar disk. A flare with rapid (~1 ks) rise time was detected during our 48 ks observation however, based on analysis of the emission-line spectrum during quiescent and flaring states, the derived plasma parameters do not seem strongly time-dependent. Density-sensitive line ratios of Ne IX and O VII indicate densities near log ne = 13. Abundance anomalies are apparent, with iron very deficient relative to oxygen, while neon is enhanced relative to oxygen. The differential emission measure derived from fluxes of temperature-sensitive emission lines shows a plasma with a sharply peaked temperature distribution, peaking at log T = 6.5. Abstract: We present high-resolution X-ray spectra of the X-ray-bright classical T Tauri star, TW Hydrae, covering the wavelength range of 1.5-25 A.
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