C IV λ1549 as an Eigenvector 1 Parameter for Active Galactic Nuclei

By J. Sulentic, R. Bachev, P. Marziani, C. Negrete, D. Dultzin. 2007

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We are exploring a spectroscopic unification for all types of broad-line emitting AGNs. The four-dimensional Eigenvector 1 (4DE1) parameter space organizes quasar diversity in a sequence primarily governed by Eddington ratio. This paper considers the role of C IV λ1549 measures as 4DE1 diagnostics. We use HST archival spectra for 130 sources with S/N high enough to permit reliable C IV λ1549 broad-component measures. We find a C IV λ1549BC profile blueshift that is strongly concentrated among (largely radio-quiet [RQ]) sources with FWHM(HβBC) ≲ 4000 km s-1 (which we call Population A). Narrow-line Seyfert 1 (NLSy1; with FWHM Hβ ≤ 2000 km s-1) sources belong to this population but do not emerge as a distinct class. The systematic blueshift, widely interpreted as arising in a disk wind/outflow, is not observed in broader line AGNs (including most radio-loud [RL] sources), which we call Population B. We find new correlations involving FWHM(C IV λ1549BC), C IV λ1549 line shift, and equivalent width only among Population A sources. Sulentic et al. suggested C IV λ1549 measures enhance an apparent dichotomy between sources with FWHM(HβBC) less and greater than 4000 km s-1, suggesting that it has more significance in the context of broad-line region structure than the more commonly discussed RL versus RQ dichotomy. Black hole masses computed from FWHM C IV λ1549BC for about 80 AGNs indicate that the C IV λ1549 width is a poor virial estimator. Comparison of mass estimates derived from HβBC and C IV λ1549 reveals that the latter show different and nonlinear offsets for Population A and B sources. A significant number of sources also show narrow-line C IV λ1549 emission that must be removed before C IV λ1549BC measures can be made and interpreted effectively. We present a recipe for C IV λ1549 narrow-component extraction.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/32ba7448e35b31dc5d8e4ddda17fb2379dfa19bf

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Citations in the corpus

A CATALOG OF QUASAR PROPERTIES FROM SLOAN DIGITAL SKY SURVEY DATA RELEASE 7 (2010, result): “…Bachev et al. 2004; Dietrich & Hamann 2004; Baskin & Laor 2005; Kollmeier et al. 2006; Fine et al. 2006, 2008; Bonning et al. 2007; Salviander et al. 2007; Sulentic et al. 2007; Shen et al. 2008a,b; Hu et al. 2008a,b; Zamfir et al. 2010; Wang et al. 2009b; Wu et al. 2009; Dong et al. 2009b,a).”
Active galactic nuclei: what’s in a name? (2017, background): “7 appear to be related to those that define the “Eigenvector 1”32 parameter space (Boroson and Green 1992; Brotherton and Francis 1999; Sulentic et al. 2000, 2007), which together highlight the great diversity of AGN even when considering only those that are both optically-selected and very…”
Biases in Virial Black Hole Masses: An SDSS Perspective (2007, background): “A central issue in this regard is to measure the masses of both inactive SMBHs and active AGNs/quasars.”
A Systematic Analysis of Fe II Emission in Quasars: Evidence for Inflow to the Central Black Hole (2008, background): “Sulentic et al. (2000a, 2000b, 2007) identified that FWHM(H BC), RFe, soft, and the velocity shift at half-maximum of the broad C iv line profile [c(1/2)] provide discrimination between different AGN types.”
Black Hole Growth to z = 2 - I: Improved Virial Methods for Measuring M_BH and L/L_Edd (2012, unknown): “0.3 from the study of (Sulentic et al. 2007, Sul07 in the present paper).”
COMPARING SINGLE-EPOCH VIRIAL BLACK HOLE MASS ESTIMATORS FOR LUMINOUS QUASARS (2012, background): “We note, however, that our quasars are luminous, and the relative strength of the narrow CIV emission may be larger for lower luminosity objects (see, e.g., Bachev et al. 2004; Sulentic et al. 2007).”
First X-ray-based statistical tests for clumpy-torus models: eclipse events from 230 years of monitoring of Seyfert AGN (2014, unknown): “…al. (2009), Me07 = Meisenheimer et al. (2007), N02 = Nagar et al. (2002), P04 = Peterson et al. (2004), R03 = Reunanen et al. (2003), S06 = Suganuma et al. (2006), S07 = Sulentic et al. (2007), S10 = Shu et al. (2010; 68 per cent uncertainties used), T95 = Tran (1995), V97 = Veilleux et al. (1997).”
On the Nature of Seyfert Galaxies with High [O III] λ5007 Blueshifts (2008, background): “Also note systematic blueshifts in high-ionization BLR emission lines in quasar samples (e.g., Gaskell 1982, Sulentic et al. 2007).”
UNIFICATION OF LUMINOUS TYPE 1 QUASARS THROUGH C iv EMISSION (2010, background): “This discussion follows from a long history, extending from Boroson & Green (1992) and Boroson (2002) to Sulentic et al. (2007) and beyond.”