Search Publications
The nature of light variations in magnetic hot stars
Niemczura, E.; Huang, L.; Krtička, J. +6 more
Magnetic stars show several types of light variability which is modulated by the stellar rotation. In chemically peculiar stars, the redistribution of the flux in the surface regions with peculiar chemical composition leads to the light variability with a typical amplitude of the order of hundredths of magnitude. The most efficient processes that …
Investigating source confusion in PMN J1603-4904
Dauser, T.; Wilms, J.; Kadler, M. +8 more
PMN J1603-4904 is a likely member of the rare class of γ-ray emitting young radio galaxies. Only one other source, PKS 1718-649, has been confirmed so far. These objects, which may transition into larger radio galaxies, are a stepping stone to understanding AGN evolution. It is not completely clear how these young galaxies, seen edge-on, can produ…
3D mapping of the neutral X-ray absorption in the local interstellar medium: the Gaia and XMM-Newton synergy
Wilms, J.; García, Javier A.; Kallman, Timothy R. +4 more
We present a three-dimensional map of the hydrogen density distribution in the Galactic interstellar medium. The hydrogen-equivalent column densities were obtained from the Exploring the X-ray Transient and variable Sky project (EXTRAS) which provides equivalent NH values from X-ray spectral fits of observations within the XMM-Newton Da…
Solar wind dynamics around a comet. The paradigmatic inverse-square-law model
Behar, E.; Tabone, B.; Saillenfest, M.
Aims: Observations of solar protons near comet 67P/Churyumov-Gerasimenko (67P) by the Rosetta spacecraft can be modelled by the planar motion in an effective magnetic field proportional to 1/r2. We aim to provide a thorough study of such dynamics, with a clear description of the behaviour of an incoming flux of particles. We will b…
Spectrophotometric Redshifts in the Faint Infrared Grism Survey: Finding Overdensities of Faint Galaxies
Gardner, Jonathan P.; Hathi, Nimish; Windhorst, Rogier +19 more
We improve the accuracy of photometric redshifts by including low-resolution spectral data from the G102 grism on the Hubble Space Telescope (HST), which assists in redshift determination by further constraining the shape of the broadband spectral energy distribution (SED) and identifying spectral features. The photometry used in the redshift fits…
Traveling Ultralow-Frequency Waves and Their Influences Over Low-Energy, Charged Particles
Zong, Qiu-Gang; Yang, Mu; Zhou, Xu-Zhi +3 more
In Earth's magnetosphere, the behavior of charged particles in response to ultralow-frequency (ULF) waves has long been understood in the framework of their resonant interactions with standing hydromagnetic waves. It has been argued that for impulse-excited waves, it may take a few wave cycles for the standing structure to be fully established; du…
The XXL Survey: XXXIII. Chandra Constraints on the AGN Contamination of z > 1 XXL Galaxy Clusters
Chiappetti, L.; Pierre, M.; Willis, J. +11 more
Context. The XMM-XXL survey has used observations from the XMM-Newton observatory to detect clusters of galaxies over a wide range in mass and redshift. The moderate PSF (FWHM 6″ on-axis) of XMM-Newton means that point sources within or projected onto a cluster may not be separated from the cluster emission, leading to enhanced luminosities and af…
Interplanetary type II radio bursts and their association with CMEs and flares
Shanmugaraju, A.; Suresh, K.; Umapathy, S. +2 more
We study the characteristics of the CMEs and their association with the end-frequency of interplanetary (IP)-type-II bursts by analyzing a set of 138 events (IP-type-II bursts–flares–CMEs) observed during the period 1997–2012. The present analysis consider only the type II bursts having starting frequency
Speckle Interferometry at the U.S. Naval Observatory. XXIII.
Mason, Brian D.; Hartkopf, William I.; Josties, Jordan D. +1 more
The results of 3989 intensified CCD observations of double stars, made with the 26-inch refractor of the U.S. Naval Observatory, are presented. Each observation of a system represents a combination of over 2000 short-exposure images. These observations are averaged into 1911 mean relative positions and range in separation from 0.″289 to 128.″638, …
Radial Velocity Comparison of Gaia DR2 and RAVE DR5 Survey: A Systematic Offset in Radial Velocities among a Group of Highly Accurate Radial Velocity Stars
Deepak; Reddy, Bacham E.
Here, we report a comparative study of radial velocity (RV) data of two major surveys: Gaia Data Release 2 and RAVE Data Release 5. We restricted the sample to stars with relatively accurate RVs ({σ }RV}{Gaia}}≤slant 2 km s-1 or ≤2%, and {σ }RV}RAVE}}≤slant 2 km s-1 or ≤2%). The dif…