Search Publications
GOODS-Herschel: the far-infrared view of star formation in active galactic nucleus host galaxies since z ≈ 3
Magnelli, B.; Lutz, D.; Altieri, B. +28 more
We present a study of the infrared properties of X-ray selected, moderate-luminosity (i.e. LX= 1042-1044 erg s-1) active galactic nuclei (AGNs) up to z ≈ 3, in order to explore the links between star formation in galaxies and accretion on to their central black holes. We use 100 and 160 µ m fluxes …
Fundamental parameters and infrared excesses of Hipparcos stars
Zijlstra, A. A.; Boyer, M. L.; McDonald, I.
We derive the fundamental parameters (temperature and luminosity) of 107 619 Hipparcos stars and place these stars on a true Hertzsprung-Russell diagram. This is achieved by comparing BT-SETTL model atmospheres to spectral energy distributions (SEDs) created from Hipparcos, Tycho, Sloan Digital Sky Survey, DENIS, Two Micron All Sky Survey, MSX, AK…
Galaxy properties from the ultraviolet to the far-infrared: Λ cold dark matter models confront observations
Somerville, Rachel S.; Primack, Joel R.; Domínguez, Alberto +1 more
We combine a semi-analytic model of galaxy formation with simple analytic recipes describing the absorption and re-emission of starlight by dust in the interstellar medium of galaxies. We use the resulting models to predict galaxy counts and luminosity functions from the far-ultraviolet (FUV) to the submillimetre, from redshift five to the present…
On the correlations between galaxy properties and supermassive black hole mass
Beifiori, A.; Corsini, E. M.; Zhu, Y. +1 more
We use a large sample of upper limits and accurate estimates of supermassive black hole (SMBH) masses coupled with libraries of host galaxy velocity dispersions, rotational velocities and photometric parameters extracted from Sloan Digital Sky Survey i-band images to establish correlations between the SMBH and host galaxy parameters. We test wheth…
Using the Fundamental Plane of black hole activity to distinguish X-ray processes from weakly accreting black holes
Anderson, Scott F.; Plotkin, Richard M.; Markoff, Sera +2 more
The Fundamental Plane of black hole activity is a relation between X-ray luminosity, radio luminosity and black hole mass for hard-state Galactic black holes and their supermassive analogues. The Fundamental Plane suggests that, at low-accretion rates, the physical processes regulating the conversion of an accretion flow into radiative energy coul…
X-ray-optical classification of cluster mergers and the evolution of the cluster merger fraction
Mann, Andrew W.; Ebeling, Harald
We present the results of a simple but robust morphological classification of a statistically complete sample of 108 of the most X-ray-luminous clusters at 0.15 ≤z≤ 0.7 observed with Chandra. Our aims are to (a) identify the most disturbed massive clusters to be used as gravitational lenses for studies of the distant Universe and as probes of part…
Evidence for ultrafast outflows in radio-quiet AGNs - III. Location and energetics
Cappi, M.; Tombesi, F.; Reeves, J. N. +1 more
Using the results of a previous X-ray photoionization modelling of blueshifted Fe K absorption lines on a sample of 42 local radio-quiet AGNs observed with XMM-Newton, in this Letter we estimate the location and energetics of the associated ultrafast outflows (UFOs). Due to significant uncertainties, we are essentially able to place only lower/upp…
Energetic galaxy-wide outflows in high-redshift ultraluminous infrared galaxies hosting AGN activity
Ivison, R. J.; Smail, Ian; Alexander, D. M. +10 more
We present integral field spectroscopy observations, covering the [O III] λλ4959, 5007 emission-line doublet of eight high-redshift (z = 1.4-3.4) ultraluminous infrared galaxies (ULIRGs) that host active galactic nucleus (AGN) activity, including known submillimetre luminous galaxies. The targets have moderate radio luminosities that are typical o…
Accurate fundamental parameters and detailed abundance patterns from spectroscopy of 93 solar-type Kepler targets
Kawaler, S. D.; Christensen-Dalsgaard, J.; García, R. A. +29 more
We present a detailed spectroscopic study of 93 solar-type stars that are targets of the NASA/Kepler mission and provide detailed chemical composition of each target. We find that the overall metallicity is well represented by Fe lines. Relative abundances of light elements (CNO) and α elements are generally higher for low-metallicity stars. Our s…
X-ray surface brightness and gas density fluctuations in the Coma cluster
Böhringer, H.; Sunyaev, R.; Churazov, E. +6 more
X-ray surface brightness fluctuations in the core (650 × 650 kpc) region of the Coma cluster observed with XMM-Newton and Chandra are analysed using a 2D power spectrum approach. The resulting 2D spectra are converted to 3D power spectra of gas density fluctuations. Our independent analyses of the XMM-Newton and Chandra observations are in excelle…