2018/01/01 by Chen Zhi-Fu, Zhifu Chen, Da-Sheng Pan +5 · 1 citation
Chemistry · Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Baryon #Chemistry #Galaxies: Formation, Evolution, Phenomena #Galaxy #Oscillation (cell signaling) #Physics #Quasar #Radio Astronomy Observations and Technology #astro-ph.GA
paper · pdf · doi:10.3847/1538-4365/aa9d90
published as 2018,ApJS,234,16 · 10 pages,12 figures
openalex publication_date 2018/01/01 · arxiv created 2018/01/24 · arxiv updated 2018/01/25 · openalex created_date 2018/02/02 · openalex updated_date 2026/08/05
Abstract Using the quasars with z em < 0.9 from the Baryon Oscillation Spectroscopic Survey, we measure the spectral characteristics, including continuum and emission lines, around the H β and H α spectral regions, which are lacking in Quasar Data Release 12 (DR12Q). We estimate the virial black hole mass from broad H α and/or H β , and infer quasar redshifts from [O iii ] λ 5007 emission lines. All the measurements and derived quantities are publicly available. A comparison between [O iii ] λ 5007 redshifts and the visual inspection redshifts included in DR12Q indicates that the visual inspection redshifts are robust. We find that the full widths at half maximum of the broad H α are consistent with those of the broad H β , while both the equivalent widths and line luminosities of the broad H α are obviously larger than the corresponding quantities of the broad H β . We also find that there is an obviously systematic offset between the H β and H α based mass if they are inferred from the empirical relationships in the literature. Using our large quasar sample, we have improved the H β and H α based mass estimators by minimizing the difference between the H β- and H α -based masses. For the black hole mass estimator (Equation (1)), we find that the coefficients ( a , b ) = (7.00, 0.50) for H α and ( a , b ) = (6.96, 0.50) for H β are the best choices.