Search Publications
A sub-kpc-scale binary active galactic nucleus with double narrow-line regions
Komossa, S.; Husemann, Bernd; Park, Daeseong +3 more
We present the kinematic properties of a type-2 Quasi stellar object (QSO), SDSS J132323.33-015941.9 at z ∼ 0.35, based on the analysis of Very Large Telescope integral field spectroscopy and Hubble Space Telescope (HST) imaging, which suggest that the target is a binary active galactic nucleus (AGN) with double narrow-line regions. The QSO featur…
The Mass of the Central Black Hole in the Nearby Seyfert Galaxy NGC 5273
Bentz, Misty C.; Jones, Jeremy; Parks, J. Robert +9 more
We present the results of a reverberation-mapping program targeting NGC 5273, a nearby early-type galaxy with a broad-lined active galactic nucleus (AGN). Over the course of the monitoring program, NGC 5273 showed strong variability that allowed us to measure time delays in the responses of the broad optical recombination lines to changes in the c…
A "breathing" source surface for cycles 23 and 24
Sun, X.; Arden, W. M.; Norton, A. A.
The potential field source surface (PFSS) model is used to represent the large-scale geometry of the solar coronal magnetic fields. The height of the source surface in this model can be taken as a free parameter. Previous work suggests that varying the source surface height during periods of solar minimum yields better agreement between PFSS model…
Three-dimensional Martian ionosphere model: II. Effect of transport processes due to pressure gradients
Forget, F.; Chaufray, J. -Y.; Leblanc, F. +7 more
To study the transport of the ionospheric plasma on Mars, we have included a 3-D multifluid dynamical core in a Martian general circulation model. Vertical transport modifies the ion density above ~160 km on the dayside, especially the ions produced at high altitudes like O+, N+, and C+. Near the exobase, the daysi…
Spectral Energy Distribution Analysis of Class I and Class II FU Orionis Stars
Gramajo, Luciana V.; Gómez, Mercedes; Rodón, Javier A.
FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphas…
Constraining supersymmetry using the relic density and the Higgs boson
Rauch, Michael; Plaszczynski, Stéphane; Henrot-Versillé, Sophie +5 more
Recent measurements by Planck, LHC experiments, and Xenon100 have significant impact on supersymmetric models and their parameters. We first illustrate the constraints in the mSUGRA plane and then perform a detailed analysis of the general minimal supersymmetric Standard Model (MSSM) with 13 free parameters. Using SFitter, Bayesian and profile lik…
Information gains from cosmic microwave background experiments
Amara, Adam; Refregier, Alexandre; Seehars, Sebastian +2 more
To shed light on the fundamental problems posed by dark energy and dark matter, a large number of experiments have been performed and combined to constrain cosmological models. We propose a novel way of quantifying the information gained by updates on the parameter constraints from a series of experiments which can either complement earlier measur…
Lens Models of Herschel-selected Galaxies from High-resolution Near-IR Observations
Ivison, R. J.; Clements, D. L.; Scott, D. +39 more
We present Keck-Adaptive Optics and Hubble Space Telescope high resolution near-infrared (IR) imaging for 500 µm bright candidate lensing systems identified by the Herschel Multi-tiered Extragalactic Survey and Herschel Astrophysical Terahertz Large Area Survey. Out of 87 candidates with near-IR imaging, 15 (~17%) display clear near-IR lensi…
The curious time lags of PG 1244+026: discovery of the iron K reverberation lag.
Fabian, A. C.; Uttley, P.; Cackett, E. M. +2 more
High-frequency iron K reverberation lags, where the red wing of the line responds before the line centroid, are a robust signature of relativistic reflection off the inner accretion disc. In this Letter, we report the discovery of the Fe K lag in PG 1244+026 from ∼120 ks of data (one orbit of the XMM-Newton telescope). The amplitude of the lag wit…
A wide search for obscured active galactic nuclei using XMM-Newton and WISE
Alexander, D. M.; Georgakakis, A.; Comastri, A. +8 more
Heavily obscured and Compton-thick active galactic nuclei (AGNs) are missing even in the deepest X-ray surveys, and indirect methods are required to detect them. Here we use a combination of the XMM-Newton serendipitous X-ray survey with the optical Sloan Digital Sky Survey (SDSS), and the infrared WISE all-sky survey in order to check the efficie…