Search Publications
Hard-X-ray spectra of active galactic nuclei in the INTEGRAL complete sample
Bird, A. J.; Ubertini, P.; Malizia, A. +4 more
In this paper, we present the hard-X-ray spectral analysis of a complete sample of active galactic nuclei (AGNs) detected by INTEGRAL/IBIS. In conjunction with IBIS spectra, we make use of Swift/BAT data, with the aim of cross-calibrating the two instruments, studying source variability and constraining some important spectral parameters. We find …
Dynamical Modeling of Galaxy Mergers Using Identikit
Yun, M. S.; Armus, L.; Surace, J. +5 more
We present dynamical models of four interacting systems: NGC 5257/8, The Mice, the Antennae, and NGC 2623. The parameter space of the encounters are constrained using the Identikit model-matching and visualization tool. Identikit utilizes hybrid N-body and test particle simulations to enable rapid exploration of the parameter space of galaxy merge…
Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC). III. Young Stellar Objects
van Loon, J. Th.; Indebetouw, R.; Hora, J. L. +15 more
The Spitzer Space Telescope Legacy Program SAGE-SMC allows global studies of resolved stellar populations in the SMC in a different environment than our Galaxy. Using the SAGE-SMC IRAC (3.6-8.0 µm) and MIPS (24 and 70 µm) catalogs and images combined with near-infrared (JHK s ) and optical (UBVI) data, we identified a popul…
Fast and slow rotators in the densest environments: a FLAMES/GIRAFFE integral field spectroscopy study of galaxies in A1689 at z = 0.183
Dalla Bontà, E.; Davies, R. L.; D'Eugenio, F. +1 more
We present FLAMES/GIRAFFE integral field spectroscopy of 30 galaxies in the massive cluster A1689 at z = 0.183. Conducting an analysis similar to that of ATLAS3D, we extend the baseline of the kinematic morphology-density relation by an order of magnitude in projected density and show that it is possible to use existing instruments to i…
Hubble Tarantula Treasury Project: Unraveling Tarantula's Web. I. Observational Overview and First Results
Panagia, N.; Anderson, J.; Zaritsky, D. +18 more
The Hubble Tarantula Treasury Project (HTTP) is an ongoing panchromatic imaging survey of stellar populations in the Tarantula Nebula in the Large Magellanic Cloud that reaches into the sub-solar mass regime (<0.5 M ⊙). HTTP utilizes the capability of the Hubble Space Telescope to operate the Advanced Camera for Surveys and the Wide …
Asynchronous formation of Hesperian and Amazonian-aged deltas on Mars and implications for climate
Hauber, E.; Platz, T.; Le Deit, L. +5 more
fluvial and lacustrine landforms on Mars are thought to be old and have formed more than ~3.8 Gyr ago, in the Noachian period. After a major climatic transition, surface liquid water became less abundant and finally disappeared almost completely. Recent work has shown that observational evidence for Hesperian and Amazonian aqueous processes is mor…
The XMM deep survey in the CDF-S. III. Point source catalogue and number counts in the hard X-rays
Brandt, W. N.; Vignali, C.; Gilli, R. +10 more
Nuclear obscuration plays a key role in the initial phases of AGN growth, yet not many highly obscured active galactic nuclei (AGN) are currently known beyond the local Universe, and their search is an active topic of research. The XMM-Newton survey in the Chandra Deep Field South (XMM-CDFS) aims at detecting and studying the spectral properties o…
High-resolution Spectroscopic Imaging of CO in a z = 4.05 Proto-cluster
Daddi, E.; Walter, F.; Riechers, D. +2 more
We present a study of the formation of clustered, massive galaxies at large look-back times via spectroscopic imaging of CO in the unique GN20 proto-cluster at z = 4.05. Existing observations show that this is a dense concentration of gas-rich, very active star forming galaxies, including multiple bright submillimeter galaxies (SMGs). Using deep, …
Kinetic Structure of Current Sheets in the Earth Magnetotail
Zelenyi, Lev; Artemyev, Anton
In this paper we present a short review of kinetic models of the thin current sheet and corresponding Cluster observations in the Earth magnetotail. We concentrate mainly on manifestations of non-fluid ion kinetic effects. We discuss the different approaches to model description of the proton component and show that current sheets observed by Clus…
Current structures associated with dipolarization fronts
Zong, Q. -G.; Sun, W. J.; Shi, Q. Q. +8 more
observational results on currents around the dipolarization fronts (DFs) of earthward flow bursts have attracted much research attention. These currents are found to have close association with substorm intensifications. This paper devotes to further study of the current system ahead and within the DFs with high-resolution magnetic field measureme…