Search Publications
Missions
Journals
Publication Years
Detection of a QPO in five XMM-Newton observations of RE J1034+396.
Fabian, A. C.; Kara, E.; Alston, W. N. +2 more
The X-ray quasi-periodic oscillation (QPO) at ∼2.6 × 10-4 Hz in RE J1034+396 has been robustly observed in the 0.2-10 keV band of one ∼90 ks XMM-Newton observation, but was not detected in subsequent observations. Here, we investigate the power spectral density (PSD) of eight archival XMM-Newton observations of RE J1034+396, and search …
Characterization of the gaseous companion κ Andromedae b. New Keck and LBTI high-contrast observations
Kuzuhara, M.; Tamura, M.; Ishii, M. +67 more
Context. We previously reported the direct detection of a low-mass companion at a projected separation of 55 ± 2 AU around the B9-type star κ Andromedae. The properties of the system (mass ratio, separation) make it a benchmark for understanding the formation and evolution of gas giant planets and brown dwarfs on wide orbits.
Aims: We present…
Active Galactic Nucleus X-Ray Variability in the XMM-COSMOS Survey
Salvato, M.; Merloni, A.; Ponti, G. +18 more
We used the observations carried out by XMM in the COSMOS field over 3.5 yr to study the long term variability of a large sample of active galactic nuclei (AGNs) (638 sources) in a wide range of redshifts (0.1 < z < 3.5) and X-ray luminosities (1041 < L 0.5-10 <1045.5). Both a simple statistical method …
The Luminosity Function of Star Clusters in 20 Star-forming Galaxies Based on Hubble Legacy Archive Photometry
Whitmore, Bradley C.; Chandar, Rupali; Ansari, Asna +4 more
Luminosity functions (LFs) have been determined for star cluster populations in 20 nearby (4-30 Mpc), star-forming galaxies based on Advanced Camera for Surveys source lists generated by the Hubble Legacy Archive (HLA). These cluster catalogs provide one of the largest sets of uniform, automatically generated cluster candidates available in the li…
Found: the progenitors of AM CVn and supernovae .Ia
Hermes, J. J.; Bell, Keaton J.; Gianninas, A. +7 more
We present optical and X-ray observations of two tidally distorted, extremely low-mass white dwarfs (WDs) with massive companions. There is no evidence of neutron stars in our Chandra and XMM observations of these objects. SDSS J075141.18-014120.9 (J0751) is an eclipsing double WD binary containing a 0.19 M⊙ WD with a 0.97 M⊙…
The interstellar cloud surrounding the Sun: a new perspective
Jenkins, Edward B.; Gry, Cécile
Aims: We offer a new, simpler picture of the local interstellar medium, made of a single continuous cloud enveloping the Sun. This new outlook enables the description of a diffuse cloud from within and brings to light some unexpected properties.
Methods: We re-examine the kinematics and abundances of the local interstellar gas, as reveal…
EMHD theory and observations of electron solitary waves in magnetotail plasmas
Pu, Zu-Yin; Xiao, Chi-Jie; Shi, Quan-Qi +4 more
A new approach of electron magnetohydrodynamics (EMHD) is developed by including the anisotropy of the electron pressure tensor to take Biermann battery effect into account. Based on the model, the dispersion relation of slow and fast electron magnetosonic modes are derived. A Korteweg-de Vries equation is then obtained from the wave equation to g…
Čerenkov Emission of Quasiparallel Whistlers by Fast Electron Phase-Space Holes during Magnetic Reconnection
Eastwood, J. P.; Andersson, L.; Goldman, M. V. +6 more
Kinetic simulations of magnetotail reconnection have revealed electromagnetic whistlers originating near the exhaust boundary and propagating into the inflow region. The whistler production mechanism is not a linear instability, but rather is Čerenkov emission of almost parallel whistlers from localized moving clumps of charge (finite-size quasipa…
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…