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On More Sensitive Periodogram Statistics
Bélanger, G.
Period searches in event data have traditionally used the Rayleigh statistic, R 2. For X-ray pulsars, the standard has been the Z 2 statistic, which sums over more than one harmonic. For γ-rays, the H-test, which optimizes the number of harmonics to sum, is often used. These periodograms all suffer from the same problem, name…
Effects of disc asymmetries on astrometric measurements. Can they mimic planets?
Schneider, J.; Souami, D.; Kral, Q. +1 more
Astrometry covers a parameter space that cannot be reached by RV or transit methods to detect terrestrial planets on wide orbits. In addition, high accuracy astrometric measurements are necessary to measure the inclination of the planet's orbits. Here we investigate the principles of an artefact of the astrometric approach, namely the displacement…
Prediction of Forbidden Ultraviolet and Visible Emissions in Comet 67P/Churyumov-Gerasimenko
Galand, Marina; Bhardwaj, Anil; Raghuram, Susarla
Remote observation of spectroscopic emissions is a potential tool for the identification and quantification of various species in comets. The CO Cameron band (to trace CO2) and atomic oxygen emissions (to trace H2O and/or CO2, CO) have been used to probe neutral composition in the cometary coma. Using a coupled-che…
Deriving Potential Coronal Magnetic Fields from Vector Magnetograms
Welsch, Brian T.; Fisher, George H.
The minimum-energy configuration for the magnetic field above the solar photosphere is curl-free (hence, by Ampère's law, also current-free), so can be represented as the gradient of a scalar potential. Since magnetic fields are divergence free, this scalar potential obeys Laplace's equation, given an appropriate boundary condition (BC). With meas…
An Integrated Model for the Production of X-Ray Time Lags and Quiescent Spectra from Homogeneous and Inhomogeneous Black Hole Accretion Coronae
Becker, Peter A.; Kroon, John J.
Many accreting black holes manifest time lags during outbursts, in which the hard Fourier component typically lags behind the soft component. Despite decades of observations of this phenomenon, the underlying physical explanation for the time lags has remained elusive, although there are suggestions that Compton reverberation plays an important ro…
Possible gamma-ray burst radio detections by the Square Kilometre Array. New perspectives
Capozziello, Salvatore; Ruggeri, Alan Cosimo
The next generation interferometric radio telescope, the Square Kilometre Array (SKA), which will be the most sensitive and largest radio telescope ever constructed, could greatly contribute to the detection, survey and characterization of Gamma Ray Bursts (GRBs). By the SKA, it will be possible to perform the follow up of GRBs even for several mo…
New Gapless COS G140L Mode Proposed for Background-limited Far-UV Observations
Anderson, Scott F.; France, Kevin; Fleming, Brian +6 more
Here we describe the observation and calibration procedure for a new G140L observing mode for the Cosmic Origins Spectrograph (COS) on board the Hubble Space Telescope (HST). This mode, CENWAV = 800, is designed to move the far-UV band fully onto the Segment A detector, allowing for more efficient observation and analysis by simplifying calibratio…
The structure and early evolution of massive star forming regions. Substructure in the infrared dark cloud SDC13
Avison, A.; Peretto, N.; Fuller, G. A. +4 more
Context. Investigations into the substructure of massive star forming regions are essential for understanding the observed relationships between core mass distributions and mass distributions in stellar clusters, differentiating between proposed mechanisms of massive star formation.
Aims: We study the substructure in the two largest fragments…
How Accurate Are Infrared Luminosities from Monochromatic Photometric Extrapolation?
Fang, Guanwen; Lin, Zesen; Kong, Xu
Template-based extrapolations from only one photometric band can be a cost-effective method to estimate the total infrared (IR) luminosities ({L}{IR}) of galaxies. By utilizing multi-wavelength data that covers across 0.35-500 µm in GOODS-North and GOODS-South fields, we investigate the accuracy of this monochromatic extrapolated …
Large-scale latitude distortions of the inner Milky Way disk from the Herschel/Hi-GAL Survey
Moore, T. J. T.; Testi, L.; Benedettini, M. +9 more
Aims: We use the Herschel Hi-GAL survey data to study the spatial distribution in Galactic longitude and latitude of the interstellar medium (ISM) and of dense, star-forming clumps in the inner Galaxy.
Methods: We assemble a complete mosaic of the inner Galaxy between l = -70° and +68° in the far-infrared continuum from Hi-GAL. The peak …