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Revisiting the oscillations in the cosmic microwave background angular power spectra at ℓ ∼ 120 in the Planck 2015 data
Ichiki, Kiyotomo; Horiguchi, Koichiro; Yokoyama, Jun'ichi
While the observed nearly scale-invariant initial power spectrum is regarded as favorable evidence of the standard inflationary cosmology, precision observations of the cosmic microwave background anisotropies also suggest possible existence of nontrivial features such as those observed around multipoles ℓ∼120 by WMAP. Here, we examine the Planck …
Concerning the helium-to-hydrogen number density ratio in very slow ejecta and winds near solar minimum
Farrugia, C. J.; Galvin, A. B.; Vasquez, Bernard J. +2 more
Near the solar minimum the average value of the helium-to-proton number density ratio is a strong function of speed. The average ratios for both solar ejecta and ambient winds obey approximately the same relation with speed. At the lowest speeds, the ratio takes on small values near and below 0.01. Here winds and ejecta with very slow speeds (≲310…
A Photometric Study of the Eclipsing Binary QT Ursae Majoris
Michaels, E. J.
Presented are the first multiband light curves of the eclipsing binary QT Ursae Majoris. The light curves were analyzed using the Wilson-Devinney program to find the best-fit stellar model. Asymmetries in the light curves required spots to be included in the model. The solution results give a Roche Lobe fill-out of 13%, which is consistent with a …
An analysis of magnetic reconnection events and their associated auroral enhancements
Reistad, J. P.; Milan, S. E.; Case, N. A. +2 more
An analysis of simultaneous reconnection events in the near-Earth magnetotail and enhancements in the aurora is undertaken. Exploiting magnetospheric data from the Geotail, Cluster, and Double Star missions, along with auroral images from the IMAGE and Polar missions, the relationship between a reconnection signature and its auroral counterpart is…
A dynamical study of the multiple system 17 Cygni ABFG
Romanenko, L. G.
Adynamical study of the relative motions of the components of the inner pairs AB (ADS 12913) and FG (ADS 12889) of the quadruple heirarchical system 17 Cygni (WDS 19464+3344) is presented, as well as analysis of themotions of the outer pair AB-FG. The study is based on CCD observations obtained on the 26-inch refractor of the Pulkovo Observatory (…
Compton thick absorber in type 1 quasar 3C 345 revealed by Suzaku and Swift/BAT
Eguchi, Satoshi
The archival data of 3C 345, a type 1 quasar at z = 0.5928, obtained with Suzaku and Swift/BAT are analysed. Though previous studies of this source applied only a simple broken power-law model, a heavily obscuring material is found to be required by considering Akaike information criteria. The application of the numerical torus model by Murphy &am…
Acceleration and particle transport in collisionless plasma in the process of dipolarization and nonstationary turbulence
Popov, V. Yu.; Petrukovich, A. A.; Zelenyi, L. M. +3 more
This work is devoted to studying the processes of the acceleration of plasma particles in thin current sheets that appear during magnetospheric substorms in the Earth's magnetosphere tail. A numerical model of magnetic dipolarization accompanied by plasma turbulence has been constructed and studied. The model allows one to investigate the particle…
A Simple Pile-up Model for Time Series Analysis
Sevilla, Diego J. R.
In this paper, a simple pile-up model is presented. This model calculates the probability P(n| N) of having n counts if N particles collide with a sensor during an exposure time. Through some approximations, an analytic expression depending on only one parameter is obtained. This parameter characterizes the pile-up magnitude, and depends on featur…
X-ray selection of Compton-Thick AGN at high redshift
Lanzuisi, G.
Compton-Thick (CT) active galactic nuclei (AGN) are a key ingredient of cosmic X-ray background (CXB) synthesis models, but are still an elusive component of the AGN population beyond the local universe. Multiwavelength surveys are the only way to find them at z > ∼ 0.1, and a deep X-ray coverage is crucial in order to clearly identify them amo…
On the nature of the candidate T-Tauri star V501 Aurigae★
Neuhäuser, R.; Ginski, C.; Mugrauer, M. +18 more
We report new multicolour photometry and high-resolution spectroscopic observations of the long-period variable V501 Aur, previously considered to be a weak-lined T-Tauri star belonging to the Taurus-Auriga star-forming region. The spectroscopic observations reveal that V501 Aur is a single-lined spectroscopic binary system with a 68.8-d orbital p…