Learn More
We use QSO emission-line widths to examine the M BH − σ * relationship as a function of redshift and to extend the relationship to larger masses. Supermassive black holes in galactic nuclei are closely related to the bulge of the host galaxy. The mass of the black hole, M BH , increases with the bulge luminosity and with the velocity dispersion of the bulge(More)
We examine the black hole mass-galaxy bulge relationship in high-redshift QSOs. Black hole masses are derived from the broad emission lines, and the host galaxy stellar velocity dispersion σ * is estimated from the widths of the radio CO emission lines. At redshifts z > 3, the CO line widths are narrower than expected for the black hole mass, indicating(More)
Astronomers knew early in the twentieth century that some galaxies have emission-line nuclei. However, even the systematic study by Seyfert (1943) was not enough to launch active galactic nuclei (AGN) as a major topic of astronomy. The advances in radio astronomy in the 1950s revealed a new universe of energetic phenomena, and inevitably led to the(More)
Recent simulations of merging black holes with spin give recoil velocities from gravitational radiation up to several thousand km s −1. A recoiling supermassive black hole can retain the inner part of its accretion disk, providing fuel for a continuing QSO phase lasting millions of years as the hole moves away from the galactic nucleus. One possible(More)
We present measurements of the gas-phase C/O abundance ratio in six H II regions in the spiral galaxies M101 and NGC 2403, based on ultraviolet spectroscopy using the Faint Object Spectrograph on the Hubble Space Telescope. The C/O ratios increase systematically with O/H in both galaxies, from log C/O ≈ −0.8 at log O/H = −4.0 to log C/O ≈ −0.1 at log O/H =(More)
The oceans at the start of the Neoproterozoic Era (1,000-541 million years ago, Ma) were dominantly anoxic, but may have become progressively oxygenated, coincident with the rise of animal life. However, the control that oxygen exerted on the development of early animal ecosystems remains unclear, as previous research has focussed on the identification of(More)
The quasar SDSS J105041.35+345631.3 (z = 0.272) has broad emission lines blueshifted by 3500 km s −1 relative to the narrow lines and the host galaxy. Such an object may be a candidate for a recoiling supermassive black hole, a binary black hole, a superposition of two objects, or an unusual geometry for the broad emission-line region (BLR). The absence of(More)
The strontium isotope composition of seawater is strongly influenced on geological time scales by changes in the rates of continental weathering relative to ocean crust alteration. However, the potential of the seawater 87 Sr/ 86 Sr curve to trace globally integrated chemical weathering rates has not been fully realised because ocean 87 Sr/ 86 Sr is also(More)
We investigate the relationship between black hole mass, M BH , and host galaxy velocity dispersion, σ * , for QSOs in Data Release 3 of the Sloan Digital Sky Survey. We derive M BH from the broad Hβ line width and continuum luminosity, and the bulge stellar velocity dispersion from the [O iii] narrow line width (σ [O III]). At higher redshifts, we use Mg(More)