Search Publications
A new approach to the long-term reconstruction of the solar irradiance leads to large historical solar forcing
Schmutz, W.; Rozanov, E.; Shapiro, A. I. +4 more
Context. The variable Sun is the most likely candidate for the natural forcing of past climate changes on time scales of 50 to 1000 years. Evidence for this understanding is that the terrestrial climate correlates positively with the solar activity. During the past 10 000 years, the Sun has experienced the substantial variations in activity and th…
Evidence for Ultra-fast Outflows in Radio-quiet Active Galactic Nuclei. II. Detailed Photoionization Modeling of Fe K-shell Absorption Lines
Cappi, M.; Dadina, M.; Tombesi, F. +3 more
X-ray absorption line spectroscopy has recently shown evidence for previously unknown Ultra-fast Outflows (UFOs) in radio-quiet active galactic nuclei (AGNs). These have been detected essentially through blueshifted Fe XXV/XXVI K-shell transitions. In the previous paper of this series we defined UFOs as those highly ionized absorbers with an outfl…
Torus and Active Galactic Nucleus Properties of Nearby Seyfert Galaxies: Results from Fitting Infrared Spectral Energy Distributions and Spectroscopy
Alonso-Herrero, Almudena; Díaz-Santos, Tanio; Asensio Ramos, Andrés +9 more
We used the CLUMPY torus models and a Bayesian approach to fit the infrared spectral energy distributions and ground-based high angular resolution mid-infrared spectroscopy of 13 nearby Seyfert galaxies. This allowed us to put tight constraints on torus model parameters such as the viewing angle i, the radial thickness of the torus Y, the angular …
Planck early results. XVIII. The power spectrum of cosmic infrared background anisotropies
Kneissl, R.; Miville-Deschênes, M. -A.; Bernard, J. -P. +202 more
Using Planck maps of six regions of low Galactic dust emission with a total area of about 140 deg2, we determine the angular power spectra of cosmic infrared background (CIB) anisotropies from multipole ℓ = 200 to ℓ = 2000 at 217, 353, 545 and 857 GHz. We use 21-cm observations of Hi as a tracer of thermal dust emission to reduce the al…
Feedback in Luminous Obscured Quasars
Ho, Luis C.; Barth, Aaron J.; Greene, Jenny E. +1 more
We use spatially resolved long-slit spectroscopy from Magellan to investigate the extent, kinematics, and ionization structure in the narrow-line regions of 15 luminous, obscured quasars with z < 0.5. Increasing the dynamic range in luminosity by an order of magnitude, as well as improving the depth of existing observations by a similar factor,…
Planck early results. XXV. Thermal dust in nearby molecular clouds
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +197 more
Planck allows unbiased mapping of Galactic sub-millimetre and millimetre emission from the most diffuse regions to the densest parts of molecular clouds. We present an early analysis of the Taurus molecular complex, on line-of-sight-averaged data and without component separation. The emission spectrum measured by Planck and IRAS can be fitted pixe…
Planck early results. XI. Calibration of the local galaxy cluster Sunyaev-Zeldovich scaling relations
Kneissl, R.; Dahle, H.; Miville-Deschênes, M. -A. +207 more
We present precise Sunyaev-Zeldovich (SZ) effect measurements in the direction of 62 nearby galaxy clusters (z < 0.5) detected at high signal-to-noise in the first Planck all-sky data set. The sample spans approximately a decade in total mass, 2 × 1014 M⊙ < M500 < 2 × 1015 M⊙, where M…
The cool-core bias in X-ray galaxy cluster samples. I. Method and application to HIFLUGCS
Paltani, S.; Molendi, S.; Eckert, D.
Aims: When selecting flux-limited cluster samples, the detection efficiency of X-ray instruments is not the same for centrally-peaked and flat objects, which introduces a bias in flux-limited cluster samples. We quantify this effect in the case of a well-known cluster sample, HIFLUGCS.
Methods: We simulate a population of X-ray clusters …
The Next Generation Atlas of Quasar Spectral Energy Distributions from Radio to X-Rays
Hines, Dean C.; Green, Richard F.; Gallagher, Sarah C. +14 more
We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating the work of Elvis et al. by using high-quality data obtained with several space- and ground-based telescopes, including NASA's Great Observatories. We present an atlas of SEDs of 85 optically bright, non-blazar quasars over the electromagnetic…
Very Strong Emission-line Galaxies in the WFC3 Infrared Spectroscopic Parallel Survey and Implications for High-redshift Galaxies
Scarlata, C.; Shim, H.; Malkan, M. +13 more
The WFC3 Infrared Spectroscopic Parallel Survey uses the Hubble Space Telescope (HST) infrared grism capabilities to obtain slitless spectra of thousands of galaxies over a wide redshift range including the peak of star formation history of the universe. We select a population of very strong emission-line galaxies with rest-frame equivalent widths…