SIMBAD references

2014ApJ...788...91G - Astrophys. J., 788, 91 (2014/June-2)

Near-infrared spectra and intrinsic luminosities of candidate Type II quasars at 2 < z < 3.4.

GREENE J.E., ALEXANDROFF R., STRAUSS M.A., ZAKAMSKA N.L., LANG D., LIU G., PATTARAKIJWANICH P., HAMANN F., ROSS N.P., MYERS A.D., BRANDT W.N., YORK D. and SCHNEIDER D.P.

Abstract (from CDS):

We present JHK near-infrared (NIR) spectroscopy of 25 candidate Type II quasars selected from the Sloan Digital Sky Survey (SDSS), using Triplespec on the Apache Point Observatory 3.5 m telescope, the Folded-port InfraRed Echellette at the Magellan/Baade 6.5 m telescope, and the Gemini Near-Infrared Spectrograph on Gemini. At redshifts of 2 < z < 3.4, our NIR spectra probe the rest-frame optical region of these targets, which were initially selected to have strong lines of C IV and Ly α, with FWHM < 2000 km/s from the SDSS pipeline. We use the [O III] λ5007 line shape as a model for the narrow-line region emission and find that Hα consistently requires a broad component with FWHMs ranging from 1000 to 7500 km/s. Interestingly, the C IV lines also require broad bases, but with considerably narrower widths of 1000-4500 km/s. Estimating the extinction using the Balmer decrement and also the relationship in lower-z quasars between rest equivalent width and luminosity in the [O III] line, we find typical AV values of 0-2 mag, which naturally explains the attenuated C IV lines relative to Hα. We propose that our targets are moderately obscured quasars. We also describe one unusual object with three distinct velocity peaks in its [O III] spectrum.

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Journal keyword(s): quasars: emission lines - quasars: general - quasars: supermassive black holes

Simbad objects: 26

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