[en] The Sloan Digital Sky Survey (SDSS) quasar J092712.65+294344.0 has been proposed as a candidate for a supermassive black hole (∼10^8.8 M _sun) ejected at high speed from the host galactic nucleus by gravitational radiation recoil, or alternatively for a supermassive black hole binary. This is based on a blueshift of 2650 km s^-1 of the broad emission lines ('b-system') relative to the narrow emission lines ('r-system') presumed to reflect the galaxy velocity. New observations with the Hobby-Eberly Telescope (HET) confirm the essential features of the spectrum. We note a third redshift system, characterized by weak, narrow emission lines of [O III] and [O II] at an intermediate velocity 900 km s^-1 redward of the broad-line velocity ('i-system'). A composite spectrum of SDSS QSOs similar to J0927+2943 illustrates the feasibility of detecting the calcium K absorption line in spectra of sufficient quality. The i-system may represent the QSO host galaxy or a companion. Photoionization requires the black hole to be ∼3 kpc from the r-system emitting gas, implying that we are observing the system only 10⁶ yr after the recoil event and contributing to the low probability of observing such a system. The HET observations give an upper limit of 10 km s^-1 per year on the rate of change of the velocity difference between the r- and b-systems, constraining the orbital phase in the binary model. These considerations and the presence of a cluster of galaxies apparently containing J0927+2943 favor the idea that this system represents a superposition of two active galactic nuclei.

[en] Recent results indicate that the compact lenticular galaxy NGC 1277 in the Perseus Cluster contains a black hole of mass ∼10¹⁰ M_☉. This far exceeds the expected mass of the central black hole in a galaxy of the modest dimensions of NGC 1277. We suggest that this giant black hole was ejected from the nearby giant galaxy NGC 1275 and subsequently captured by NGC 1277. The ejection was the result of gravitational radiation recoil when two large black holes merged following the merger of two giant ellipticals that helped to form NGC 1275. The black hole wandered in the cluster core until it was captured in a close encounter with NGC 1277. The migration of black holes in clusters may be a common occurrence

[en] We investigate the relationship between the mass of the central supermassive black hole, M _BH, and the host galaxy luminosity, L _gal, in a sample of quasars from the Sloan Digital Sky Survey Data Release 7. We use composite quasar spectra binned by black hole mass and redshift to assess galaxy features that would otherwise be overwhelmed by noise in individual spectra. The black hole mass is calculated using the photoionization method, and the host galaxy luminosity is inferred from the depth of the Ca II H+K features in the composite spectra. We evaluate the evolution in the M _BH-L _gal relationship by examining the redshift dependence of Δ log M _BH, the offset in M _BH from the local M _BH-L _gal relationship. There is little systematic trend in Δ log M _BH out to z = 0.8. Using the width of the [O III] emission line as a proxy for the stellar velocity dispersion, σ_*, we find agreement of our derived host luminosities with the locally observed Faber-Jackson relation. This supports the utility of the width of the [O III] line as a proxy for σ_* in statistical studies

[en] We compare QSO emission-line spectra to predictions based on theoretical ionizing continua of accretion disks. The observed line intensities do not show the expected trend of higher ionization with theoretical accretion disk temperature as predicted from the black hole mass and accretion rate. Consistent with earlier studies, this suggests that the inner disk does not reach temperatures as high as expected from standard disk theory. Modified radial temperature profiles, taking account of winds or advection in the inner disk, achieve better agreement with observation. The emission lines of radio-detected and radio-undetected sources show different trends as a function of the theoretically predicted disk temperature.

[en] We present active galactic nuclei (AGNs) from the Sloan Digital Sky Survey (SDSS) having double-peaked profiles of [O III]λλ5007, 4959 and other narrow emission lines, motivated by the prospect of finding candidate binary AGNs. These objects were identified by means of a visual examination of 21,592 quasars at z < 0.7 in SDSS Data Release 7 (DR7). Of the spectra with adequate signal-to-noise, 148 spectra exhibit a double-peaked [O III] profile. Of these, 86 are Type 1 AGNs and 62 are Type 2 AGNs. Only two give the appearance of possibly being optically resolved double AGNs in the SDSS images, but many show close companions or signs of recent interaction. Radio-detected quasars are three times more likely to exhibit a double-peaked [O III] profile than quasars with no detected radio flux, suggesting a role for jet interactions in producing the double-peaked profiles. Of the 66 broad-line (Type 1) AGNs that are undetected in the FIRST survey, 0.9% show double-peaked [O III] profiles. We discuss statistical tests of the nature of the double-peaked objects. Further study is needed to determine which of them are binary AGNs rather than disturbed narrow line regions, and how many additional binaries may remain undetected because of insufficient line-of-sight velocity splitting. Previous studies indicate that 0.1% of SDSS quasars are spatially resolved binaries, with typical spacings of ∼10-100 kpc. If a substantial fraction of the double-peaked objects are indeed binaries, then our results imply that binaries occur more frequently at smaller separations (<10 kpc). This suggests that simultaneous fueling of both black holes is more common as the binary orbit decays through these spacings.

[en] The blazar 3C 454.3 was revealed by the Fermi Gamma-ray Space Telescope to be in an exceptionally high flux state in 2008 July. Accordingly, we performed a multiwavelength monitoring campaign from 2008 August through December on this blazar using infrared (IR) and optical observations from the Small and Moderate Aperture Research Telescope System telescopes, optical, ultraviolet (UV), and X-ray data from the Swift satellite, and public-release gamma-ray data from Fermi. We find an excellent correlation between the IR, optical, UV, and gamma-ray light curves, with a time lag of less than one day. The amplitude of the IR variability is comparable to that in gamma-rays, and larger than at optical or UV wavelengths. The X-ray flux is not correlated with either the gamma-rays or longer wavelength data. These variability characteristics find a natural explanation in the external Compton model, in which electrons with Lorentz factor γ ∼ 10^3-4 radiate synchrotron emission in the IR-optical and also scatter accretion disk or emission line photons to gamma-ray energies, while much cooler electrons (γ ∼ 10^1-2) produce X-rays by scattering synchrotron or other ambient photons.

[en] We present the time variability properties of a sample of six blazars, AO 0235+164, 3C 273, 3C 279, PKS 1510–089, PKS 2155–304, and 3C 454.3, at optical-IR frequencies as well as γ-ray energies. These observations were carried out as a part of the Yale/SMARTS program during 2008-2010 that has followed the variations in emission of the bright Fermi Large Area Telescope monitored blazars in the southern sky with closely spaced observations at BVRJK bands. We find that the optical-near IR variability properties are remarkably similar to those at the γ-ray energies. The discrete auto-correlation functions of the variability of these six blazars at optical-IR and γ-ray energies do not show any periodicity or characteristic timescale. The power spectral density (PSD) functions of the R-band variability of all six blazars are fit well by simple power-law functions with negative slopes such that there is higher amplitude variability on longer timescales. No clear break is identified in the PSD of any of the sources. The average slope of the PSD of R-band variability of these blazars is similar to what was found by the Fermi team for the γ-ray variability of a larger sample of bright blazars. This is consistent with leptonic models where the optical-IR and γ-ray emission is generated by the same population of electrons through synchrotron and inverse Compton processes, respectively. The prominent flares present in the optical-IR as well as the γ-ray light curves of these blazars are predominantly symmetric, i.e., have similar rise and decay timescales, indicating that the long-term variability is dominated by the crossing time of radiation or a disturbance through the emission region rather than by the acceleration or energy-loss timescales of the radiating electrons. For the blazar 3C 454.3, which has the highest-quality light curves, the total energy output, the ratio of γ-ray to optical energy output, and the γ-ray versus optical flux relation differ in the six individual flares observed between 2009 August and December. The results are consistent with the location of a large γ-ray outburst in 3C 454.3 during 2009 December being in the jet at ∼18 pc from the central engine. This poses strong constraints on the models of high-energy emission in the jets of blazars.

[en] We present multi-epoch optical observations of the blazar 3C 454.3 (z = 0.859) from 2008 August through 2011 December, using the Small and Medium Aperture Research Telescope System Consortium 1.5 m + RCSpectrograph and 1.3 m + ANDICAM in Cerro Tololo, Chile. The spectra reveal that the broad emission lines Mg II, Hβ, and Hγ are far less variable than the optical or γ-ray continuum. Although the γ-rays varied by a factor of 100 above the EGRET era flux, the lines generally vary by a factor of two or less. Smaller variations in the γ-ray flux did not produce significant variation in any of the observed emission lines. Therefore, to first order, the ionizing flux from the disk changes only slowly during large variations of the jet. However, two exceptions in the response of the broad emission lines are reported during the largest γ-ray flares in 2009 December and 2010 November, when significant deviations from the mean line flux in Hγ and Mg II were observed. Hγ showed a maximum 3σ and 4σ deviation in each flare, respectively, corresponding to a factor of 1.7 and 2.5 increase in flux. Mg II showed a 2σ deviation in both flares; no variation was detected in Hβ during either flare. These significant deviations from the mean line flux also coincide with 7 mm core ejections reported previously (Jorstad et al.). The correlation of the increased emission line flux with millimeter core ejections and γ-ray, optical, and ultraviolet flares suggests that the broad-line region extends beyond the γ-emitting region during the 2009 and 2010 flares.

[en] We report the discovery of an anomalous flare in a bright blazar, namely, PKS 0208–512, one of the targets of the Yale/SMARTS optical-near-IR (OIR) monitoring program of Fermi blazars. We identify three intervals during which PKS 0208–512 undergoes outbursts at OIR wavelengths lasting for ∼>3 months. Its brightness increases and then decreases again by at least 1 mag in these intervals. In contrast, the source undergoes bright phases in GeV energies lasting ∼>1 month during intervals 1 and 3 only. The OIR outburst during interval 2 is comparable in brightness and temporal extent to the OIR flares during intervals 1 and 3, which do have γ-ray counterparts. By analyzing the γ-ray, OIR, and supporting multi-wavelength variability data in details, we speculate that the OIR outburst during interval 2 was caused by a change in the magnetic field without any change in the total number of emitting electrons or Doppler factor of the emitting region. Alternatively, it is possible that the location of the outburst in the jet during interval 2 was closer to the black hole where the jet is more compact and the bulk Lorentz factor of the material in the jet is smaller. We also discuss the complex OIR spectral behavior during these three intervals.

[en] We present Hubble Space Telescope (HST) and United Kingdom Infrared Telescope spectra and images of the 2 kpc (0.''3) binary quasar LBQS 0103-2753 (z = 0.858). The HST images (V and I bands) show tidal features demonstrating that this system is a major galaxy merger in progress. A two-color composite image brings out knots of star formation along the tidal arc and elsewhere. The infrared spectrum shows that both objects are at the same redshift and that the discrepant redshift of C IV in component A is not representative of the true systemic redshift of this component. LBQS 0103-2753 is one of the most closely spaced binary QSOs known and is one of the relatively few dual active galactic nuclei showing confirmed broad emission lines from both components. While statistical studies of binary QSOs suggest that simultaneous fueling of both black holes during a merger may be relatively rare, LBQS 0103-2753 demonstrates that such fueling can occur at high luminosity at a late stage in the merger at nuclear spacing of only a few kpc, without severe obscuration of the nuclei.