Search Publications

Estimating Black Hole Masses of AGNs using Ultraviolet Emission Line Properties

Wang, Ran; Wu, Xue-Bing; Kong, Min-Zhi +1 more

Based on measured broad line region sizes in the reverberation-mapping AGN sample, two new empirical relations are introduced to estimate the central black hole masses of radio-loud high-redshift (z>0.5) AGNs. First, using the archival IUE/HST spectroscopy data at UV band for the reverberation-mapping objects, we obtained two new empirical rela…

Nuclear Starburst Activity in the Seyfert 2 Galaxy NGC 2273

Gu, Qiu-Sheng; Lei, Shi-Jun; Shi, Lei +2 more

We present spectrophotometric results of the Seyfert 2 galaxy NGC 2273. The presence of high-order Balmer absorption lines (H8, H9, H10) and weak equivalent widths of CaII K λ3933, CN λ4200, G-band λ4300 and MgIb λ5173 clearly indicate recent star-forming activity in the nuclear region. Using a simple stellar population synthesis model, we find th…

Measuring the Fundamental Parameters of Hot Hydrogen-Rich White Dwarfs

Barstow, M. A.

This review considers the observations of hot, hydrogen-rich white dwarf stars, with particular reference to measurements of temperature, surface gravity and composition. Spectroscopic data from a variety of wavelength ranges are required for this work and, in particular, the important contributions from optical, ultraviolet and extreme ultraviole…

Infall and Outflow Activities in the Be star FY CMa

Cao, Hui-Lai

Unusual activity of outflow mass motion connected with infall events was recorded for the B0.5 IVe star FY CMa in February 1987 from both archival IUE spectrograms of circumstellar N resonance lines and optical spectra of Hα and He λ5876 Å emission lines which showed inverse P Cygni-type profiles. We estimate the mass loss rate using ultraviolet S…