Observational Studies of Early-type Binary Stars: MP Centauri

We present photometric and spectroscopic data on the early-type binary MP Centauri. The photometric data are analyzed simultaneously with radial velocities to derive preliminary absolute dimensions for the binary components. Analysis of the spectra shows that the stars rotate synchronously and that the line of sight to the system crosses two kinematically sharp and well-separated interstellar reddening sources. It is shown that MP Cen consists of a B3 primary with M_1 = 11.4 +/- 0.4 M_sun, R_1 = 7.7 +/- 0.1 R_sun and a lobe-filling B6-B7 secondary with M_2 = 4.4 +/- 0.2 M_sun, R_2 = 6.6 +/- 0.1 R_sunComment: Accepted for publication in the MNRA

An Optical Spectroscopic Atlas of Low-Redshift Active Galactic Nuclei

We present a spectral atlas of the Hβ region for 215 type 1 AGNs (luminous Seyfert 1/radio galaxy nuclei and low-z quasars) up to z ≈ 0.8. Line profiles and measures were derived from the database of intermediate resolution spectra (R 1000) with average continuum level S/N ratio ≈30. Parameters including rest frame equivalent width and FWHM are provided for the Fe IIopt blend at λ4570, Hβ, He II λ4686, and the [O III] λλ4959, 5007 emission lines. We extract clean broad component Hβ profiles and provide wavelength measurements at 0, 1/4, 1/2, 3/4, and 0.9 peak intensity levels in order to permit a quantitative definition of the Hβ broad component for statistical studies. We also discuss sources of uncertainty, selection effects, and biases in our sample. The data are especially important for tests of the eigenvector 1 parameter space occupation and correlation. We show that the I Zw 1 template Fe IIopt spectrum reproduces well the observed Fe IIopt emission for a wide range of line width and strength. A detailed analysis of the data within the eigenvector 1 context is deferred to a companion paper