Artículo de revista
WEAK LINE QUASARS AT HIGH REDSHIFT: EXTREMELY HIGH ACCRETION RATES OR ANEMIC BROAD-LINE REGIONS?
Fecha
2010-09-28Registro en:
The Astrophysical Journal Letters, 722:L152–L156
doi:10.1088/2041-8205/722/2/L152
Autor
Lira Teillery, Paulina
Institución
Resumen
We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with
exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z = 3.55 and
SDSS J123743.08+630144.9 at z = 3.49. In both sources, we detect an unusually weak broad Hβ line and place
tight upper limits on the strengths of their [Oiii] lines. Virial, Hβ-based black hole mass determinations indicate
normalized accretion rates of L/LEdd= 0.4 for these sources, which is well within the range observed for typical
quasars with similar luminosities and redshifts.We also present high-quality XMM-Newton imaging spectroscopy of
SDSS J114153.34+021924.3 and find a hard-X-ray photon index of Γ = 1.91+0.24
−0.22, which supports the virial L/LEdd
determination in this source. Our results suggest that theweakness of the broad emission lines inWLQsis not a consequence
of an extreme continuum-emission source but instead due to abnormal broad emission line region properties.