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The 4 Ms Chandra Deep Field-South Number Counts Apportioned by Source Class: Pervasive Active Galactic Nuclei and the Ascent of Normal Galaxies
Lehmer, B. D.; Hornschemeier, A. E.; Ptak, A. +13 more
We present 0.5-2 keV, 2-8 keV, 4-8 keV, and 0.5-8 keV (hereafter soft, hard, ultra-hard, and full bands, respectively) cumulative and differential number-count (log N-log S) measurements for the recently completed ≈4 Ms Chandra Deep Field-South (CDF-S) survey, the deepest X-ray survey to date. We implement a new Bayesian approach, which allows rel…
Spectrophotometric Libraries, Revised Photonic Passbands, and Zero Points for UBVRI, Hipparcos, and Tycho Photometry
Murphy, Simon; Bessell, Michael
We have calculated improved photonic passbands for the UBVRI, Hipparcos Hp, and Tycho BT and VT standard systems using the extensive spectrophotometric libraries of NGSL and MILES. Using the Hp passband, we adjusted the absolute flux levels of stars in the spectrophotometric libraries so that their synth…
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…
The suppression of star formation by powerful active galactic nuclei
Altieri, B.; Aussel, H.; Elbaz, D. +75 more
The old, red stars that constitute the bulges of galaxies, and the massive black holes at their centres, are the relics of a period in cosmic history when galaxies formed stars at remarkable rates and active galactic nuclei (AGN) shone brightly as a result of accretion onto black holes. It is widely suspected, but unproved, that the tight correlat…
The dust scaling relations of the Herschel Reference Survey
Clements, D. L.; Ciesla, L.; Boquien, M. +23 more
We combine new Herschel/SPIRE sub-millimeter observations with existing multiwavelength data to investigate the dust scaling relations of the Herschel Reference Survey, a magnitude-, volume-limited sample of ~300 nearby galaxies in different environments. We show that the dust-to-stellar mass ratio anti-correlates with stellar mass, stellar mass s…
Local Kinetic Effects in Two-Dimensional Plasma Turbulence
Veltri, P.; Califano, F.; Servidio, S. +1 more
Using direct numerical simulations of a hybrid Vlasov-Maxwell model, kinetic processes are investigated in a two-dimensional turbulent plasma. In the turbulent regime, kinetic effects manifest through a deformation of the ion distribution function. These patterns of non-Maxwellian features are concentrated in space nearby regions of strong magneti…
HerMES: deep number counts at 250 µm, 350 µm and 500 µm in the COSMOS and GOODS-N fields and the build-up of the cosmic infrared background
Berta, S.; Aussel, H.; Le Floc'h, E. +58 more
Aims: The Spectral and Photometric Imaging REceiver (SPIRE) onboard the Herschel space telescope has provided confusion limited maps of deep fields at 250 µm, 350 µm, and 500 µm, as part of the Herschel Multi-tiered Extragalactic Survey (HerMES). Unfortunately, due to confusion, only a small fraction of the cosmic infrared b…
Particle Acceleration in the Magnetotail and Aurora
Zelenyi, L. M.; Baker, D. N.; Artemyev, A. V. +3 more
This paper deals with acceleration processes in the magnetotail and the processes that enhance particle precipitation from the tail into the ionosphere through electric fields in the auroral acceleration region, generating or intensifying discrete auroral arcs. Particle acceleration in the magnetotail is closely related to substorms and the occurr…
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…
Electric structure of dipolarization front at sub-proton scale
André, M.; Vaivads, A.; Huang, S. Y. +2 more
Using Cluster data, we investigate the electric structure of a dipolarization front (DF) - the ion inertial length (c/ωpi) scale boundary in the Earth's magnetotail formed at the front edge of an earthward propagating flow with reconnected magnetic flux. We estimate the current density and the electron pressure gradient throughout the D…