Be Envelope Properties Determined from Fe II Emission Lines
نویسندگان
چکیده
منابع مشابه
Observations of O I and Ca II Emission Lines in Quasars : Implications for the Site of Fe II Line Emission
We present results of the near-infrared (IR) spectroscopy of six quasars whose redshifts ranging from 0.158 to 1.084. Combined with the satellite ultraviolet data, it is given the relative line strengths of O I λ1304, λ8446, and λ11287, and near-IR Ca II triplet. In addition, corresponding O I line strengths measured in Seyfert 1s and narrow-line Seyfert 1s are collected from literature. These ...
متن کاملDetection of variable Si II , Mn II and Fe II emission lines in the magnetic Bp star a Centauri ⋆
Context. The nature of non-variable high-excitation emission lines detected in the optical spectra of normal late-B type and chemically peculiar HgMn and PGa stars is still poorly understood. Aims. To better understand the origin of the weak emission lines in B type stars it is especially important to investigate the spectra of a variety of stars to search for correlations between the emergence...
متن کاملFe II emission lines in the UV spectrum of Sirius - A and Vega
We present high-quality HST/GHRS spectra in the Hydrogen Lα spectral region of Vega and Sirius-A. Thanks to the signal-to-noise ratio achieved in these observations and to the similarity of the two spectra, we found clear evidence of emission features in the low flux region, λλ1190-1222Å. These emission lines can be attributed unambiguously to Fe ii and Cr ii transitions. In this spectral range...
متن کاملAn investigation of Fe emission lines in solar flare spectra
Previously, large discrepancies have been found between theory and observation for Fe emission line ratios in solar flare spectra covering the 224–327 Å wavelength range, obtained by the Naval Research Laboratory’s S082A instrument on board Skylab. These discrepancies have been attributed to either errors in the adopted atomic data or the presence of additional atomic processes not included ...
متن کاملFe K EMISSION LINES IN LOW-LUMINOSITY AGNS
We present the results of a systematic analysis of Fe K emission lines in low-luminosity AGNs (LLAGNs) observed with ASCA. We used a sample of LLAGNs with small intrinsic absorption to compare with luminous AGNs and accretion models. Some objects show an Fe line at 6.4 keV or 6.7 keV, and the rest of the objects show no significant Fe K emission line. We made a composite spectrum of sources wit...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: International Astronomical Union Colloquium
سال: 2000
ISSN: 0252-9211
DOI: 10.1017/s0252921100056414