Search Publications
Improved V II Log(gf) Values, Hyperfine Structure Constants, and Abundance Determinations in the Photospheres of the Sun and Metal-poor Star HD 84937
Sneden, C.; Wood, M. P.; Lawler, J. E. +2 more
New experimental absolute atomic transition probabilities are reported for 203 lines of V II. Branching fractions are measured from spectra recorded using a Fourier transform spectrometer and an echelle spectrometer. The branching fractions are normalized with radiative lifetime measurements to determine the new transition probabilities. Generally…
Exploiting the full potential of photometric quasar surveys: optimal power spectra through blind mitigation of systematics
Leistedt, Boris; Peiris, Hiranya V.
We present optimal measurements of the angular power spectrum of the XDQSOz catalogue of photometric quasars from the Sloan Digital Sky Survey. These measurements rely on a quadratic maximum likelihood estimator that simultaneously measures the auto- and cross-power spectra of four redshift samples, and provides minimum-variance, unbiased estimate…
HCN ice in Titan's high-altitude southern polar cloud
Maltagliati, Luca; Vinatier, Sandrine; de Kok, Remco J. +2 more
Titan's middle atmosphere is currently experiencing a rapid change of season after northern spring arrived in 2009 (refs 1, 2). A large cloud was observed for the first time above Titan's southern pole in May 2012, at an altitude of 300 kilometres. A temperature maximum was previously observed there, and condensation was not expected for any of Ti…
Mechanisms and Observations of Coronal Dimming for the 2010 August 7 Event
Thompson, B. J.; Mason, James Paul; Woods, T. N. +2 more
Coronal dimming of extreme ultraviolet (EUV) emission has the potential to be a useful forecaster of coronal mass ejections (CMEs). As emitting material leaves the corona, a temporary void is left behind which can be observed in spectral images and irradiance measurements. The velocity and mass of the CMEs should impact the character of those obse…
A Sensitive Identification of Warm Debris Disks in the Solar Neighborhood through Precise Calibration of Saturated WISE Photometry
Metchev, Stanimir A.; Heinze, Aren; Patel, Rahul I.
We present a sensitive search for WISE W3 (12 µm) and W4 (22 µm) excesses from warm optically thin dust around Hipparcos main sequence stars within 75 pc from the Sun. We use contemporaneously measured photometry from WISE, remove sources of contamination, and derive and apply corrections to saturated fluxes to attain optimal sensitivi…
Spatial variation in the plasma sheet composition: Dependence on geomagnetic and solar activity
Kistler, L. M.; Maggiolo, R.
We study the spatial distribution of plasma sheet O+ and H+ ions using data from the COmposition and DIstribution Function (CODIF) instrument on board the Cluster spacecraft from 2001 to 2005. The densities are mapped along magnetic field lines to produce bidimensional density maps at the magnetospheric equatorial plane for v…
Mapping the Particle Acceleration in the Cool Core of the Galaxy Cluster RX J1720.1+2638
Brunetti, G.; Giacintucci, S.; Venturi, T. +4 more
We present new deep, high-resolution radio images of the diffuse minihalo in the cool core of the galaxy cluster RX J1720.1+2638. The images have been obtained with the Giant Metrewave Radio Telescope at 317, 617, and 1280 MHz and with the Very Large Array at 1.5, 4.9, and 8.4 GHz, with angular resolutions ranging from 1'' to 10''. This represents…
Spectral and Morphological Analysis of the Remnant of Supernova 1987A with ALMA and ATCA
Baes, Maarten; Matsuura, Mikako; Fransson, Claes +18 more
We present a comprehensive spectral and morphological analysis of the remnant of supernova (SN) 1987A with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA). The non-thermal and thermal components of the radio emission are investigated in images from 94 to 672 GHz (λ 3.2 mm to 450 µm), w…
Observations of MCG-5-23-16 with Suzaku, XMM-Newton and NuSTAR: Disk Tomography and Compton Hump Reverberation
Harrison, F. A.; Craig, W.; Stern, D. +12 more
MCG-5-23-16 is one of the first active galactic nuclei (AGNs) where relativistic reverberation in the iron K line originating in the vicinity of the supermassive black hole was found, based on a short XMM-Newton observation. In this work, we present the results from long X-ray observations using Suzaku, XMM-Newton, and NuSTAR designed to map the e…
Evidence for major mergers of galaxies at 2 ≲ z < 4 in the VVDS and VUDS surveys
Kneib, J. -P.; Maccagni, D.; Ilbert, O. +20 more
Context. The mass assembly of galaxies can proceed through different physical processes. Here we report on the spectroscopic identification of close physical pairs of galaxies at redshifts 2 ≲ z< 4 and discuss the impact of major mergers in building galaxies at these early cosmological times.
Aims: We aim to identify and characterize close…