UV matching and detection probabilities are given for all the quasars, including dependencies on separation, optical brightness, and redshift. The rest-frame far to extreme ultraviolet (UV) colour–redshift relationship has been constructed from data on over $480\, 000$ quasars carefully cross-matched between SDSS Data Release 14 and the final GALEX photometric catalogue. Our results suggest possible improvements for the adopted modelling of the filtering mass and metal ejection in low-mass haloes. The simulated DLA metallicity distribution is in relatively good agreement with observations, but our model predicts an excess of DLAs at low metallicities. We found the outflows have a wide range of ionization parameters, $-4\lesssim\log U\lesssim 1.2$ and densities, $2.8\lesssim\log n\lesssim8\ \rm[cm^$. We present the first systematic study of 50 low redshift ($0.66 < z < 1.63$) iron low-ionization broad absorption-line quasars (FeLoBALQs) using $SimBAL$ which represents a more than five-fold increase in the number of FeLoBALQs with detailed absorption line spectral analyses.
Quasar spectra full#
A compected version of the full set of figures is shown in Appendix E. Note that the spectra have not been corrected for telluric absorption (marked with a grey band at ∼ 7600 Å). In cases where the template is also shown in blue, we were not able to fit both optical and infrared data simultaneously The blue template then indicates the best fit to the infrared data only, and the corresponding A(V) is given as A(V) blue. The dust reddening applied in the rest-frame of the quasar, A(V), and absorber, A(V) abs, assumes the SMC and LMC extinction laws, respectively. (2016) reddened by the best-fit dust model (indicated in the upper right corner). The red curve shows the redshifted composite quasar template of Selsing et al. In the upper right corner we provide the estimated emission redshift and rest-frame V -band extinction. The filled, red squares indicate the SDSS and UKIDSS photometric data points. These cases are marked by the label 'int' in the lower left corner of the figure. For spectra observed with the INT, the spectra are binned by a factor of 8 for visual clarity. The observed spectrum is shown as a solid black curve. The entire figure set is available online. = 2-3.Sample figure of the observed quasar spectra. An electronic table of the median quasar template is available. Stellar absorption lines, including higher-order Balmer lines, seen in the composites suggest that young or intermediate age stars make a significant contribution to the light of the host galaxies. The more » abrupt change in slope can be accounted for partly by host galaxy contamination at low redshift. The frequency power law index, alpha_nu, is -0.44 from 1300 - 5000A, and -2.45 redward of about 5000A. At wavelengths longer than the Ly-a emission, the continuum of the geometric mean composite is well-fit by two power-laws, with a break at approximately 5000A. The magnitude of the forbidden line shifts is < 100 km/s, compared to shifts of up to 550 km/s for some of the permitted and semi-forbidden lines.
Emission line peak velocity shifts of the broad permitted and semi-forbidden lines are strongly correlated with ionization energy, as previously suggested, but we find that the narrow forbidden lines are also shifted by amounts which are strongly correlated with ionization energy. We have identified over 80 emission line features in the spectrum. The median composite covers a rest wavelength range from 800 - 8555A, and reaches a peak signal-to-noise ratio of over 300 per 1A resolution element in the rest frame. The quasar sample spans a redshift range of 0.044 <= z <= 4.789, and an absolute r' magnitude range of -18.0 to -26.5. We have created a variety of composite quasar spectra using a homogeneous data set of over 2200 spectra from the Sloan Digital Sky Survey (SDSS).
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