Speaker
Description
We present a UV parameter space as a spectroscopical sequence to organize quasars along the spectral diversity. In the optical range, quasar spectral diversity has been analyzed using the so-called Eigenvector 1 (E1) "main sequence", which involves the FWHM of the broad component of Hb and the flux ratio of FeII and Hb. The E1 also provides information on the physical conditions of the optical emitting regions, black hole masses, or accretion rates. We lack a diagram that organizes the spectral differences in the UV range. In part because the low S/N associated with distant objects does not permit us to carefully deconvolve the most prominent lines, such as CIV and the 1900A blend that includes the intermediate ionization lines CIII], SiIII, and AlIII. The 1900A blend emission lines are closely related to the physical conditions of the broad line region, including metallicity, density, and ionization parameter. In this work, we propose to use flux ratios in the 1900 A blend to build a diagram to organize the UV spectra into a sequence. We use the average spectra for each SDSS-V object to increase the S/N to avoid a large scatter in the UV diagram. Dividing this diagram into bins, we made average spectra for each one to analyze the line emissions in three regions: 1900A blend, CIV1549, and SiIV1400, to show the particular spectral characteristics in each bin. We present a preliminar analysis of the trends in those bins, such as the black hole masses and the accretion rates.
