Search Publications
Infrared characteristics of the BIS catalog objects
Nesci, R.; Rossi, C.; Gaudenzi, S. +3 more
We studied several color-color infrared diagrams of the 276 late type stars of the BIS catalog. For 95 of these stars we derived spectral classification from our slit spectroscopy. From the 2MASS color diagram we concluded that none of the sample stars is a dwarf. The WISE 3.4-12 vs 12-22 plot is the best to discriminate the variability type (Mira…
Fundamental Parameters of the Eclipsing Binary TU Canis Majoris
Mennickent, R. E.; Garcés L., J.; Zharikov, S.
We present a spectroscopic and photometric study of the eclipsing binary TU Canis Majoris aimed to obtain their fundamental stellar parameters and evolutionary stage. Our results indicate that the masses, radii, temperatures, and luminosities for the primary and secondary stars are: {M}1=1.761+/- 0.012 {M}⊙ , {M}2=…
Unveiling multiple AGN activity in galaxy mergers
Bianchi, S.; Guainazzi, M.; Vignali, C. +13 more
In this paper we present an overview of the MAGNA (Multiple AGN Activity) project aiming at a comprehensive study of multiple super-massive black hole systems. With the main goal of characterizing the sources in merging systems at different stages of evolution, we selected a sample of objects optically classified as multiple systems on the basis o…
Long- and Mid-Term Variations of the Soft X-ray Flare Type in Solar Cycles
Chertok, I. M.; Belov, A. V.
Using data from the Geostationary Operational Environmental Satellites (GOES) spacecraft in the 1 - 8 Å wavelength range for Solar Cycles 23, 24, and part of Cycles 21 and 22, we compare mean temporal parameters (rise and decay times, and duration) and the proportion of impulsive short-duration events (SDE) and gradual long-duration events (LDE) a…
Analysis of Quasi-periodic Oscillations and Time Lag in Ultraluminous X-Ray Sources with XMM-Newton
Zhang, Shu; Li, Zi-Jian; Xiao, Guang-Cheng +6 more
We investigated the power density spectrum (PDS) and time lag of ultraluminous X-ray sources (ULXs) observed by XMM-Newton. We determined the PDSs for each ULX and found that five of them show intrinsic variability due to obvious quasi-periodic oscillations (QPOs) of mHz-1 Hz, consistent with previous reports. We further investigated these five UL…
A curious ringlet that shares Prometheus' orbit but precesses like the F ring
Hedman, M. M.; Carter, B. J.
Images obtained by the Cassini spacecraft of the region just beyond Saturn's main rings reveal a previously unreported narrow and dusty ringlet that has dynamical connections with both Saturn's small satellite Prometheus and the F ring. The radial position of this ringlet is observed to vary with time and longitude, indicating that it is eccentric…
Application of beam deconvolution technique to power spectrum estimation for CMB measurements
Keihänen, E.; Kurki-Suonio, H.; Reinecke, M. +1 more
We present two novel methods for the estimation of the angular power spectrum of cosmic microwave background (CMB) anisotropies. We assume an absolute CMB experiment with arbitrary asymmetric beams and arbitrary sky coverage. The methods differ from the earlier ones in that the power spectrum is estimated directly from the time-ordered data, witho…
A Novel Pixel-Level Image Matching Method for Mars Express HRSC Linear Pushbroom Imagery Using Approximate Orthophotos
Geng, Xun; Xu, Qing; Lan, Chaozhen +2 more
Mars topographic data, such as digital orthophoto maps (DOMs) and digital elevation models (DEMs) are essential to planetary science and exploration missions. The main objective of our study is to generate a higher resolution DEM using the Mars Express (MEX) High Resolution Stereo Camera (HRSC). This paper presents a novel pixel-level image matchi…
Distant clusters of galaxies in the 2XMM/SDSS footprint: follow-up observations with the LBT
Takey, A.; Schwope, A.; Lamer, G. +1 more
Context. Galaxy clusters at high redshift are important to test cosmological models and models for the growth of structure. They are difficult to find in wide-angle optical surveys, however, leaving dedicated follow-up of X-ray selected candidates as one promising identification route.
Aims: We aim to increase the number of galaxy clusters be…
30 years of the Vega mission: Comparison of some properties of the 1P/Halley and 67P/Churyumov-Gerasimenko comets
Ksanfomality, L. V.
On March 6 and 9, 1986, for the first time in the history of science, the Russian spacecraft Vega-1 and Vega-2 approached and closely passed by the nucleus of Halley’s comet (1P/Halley). A few days later, on March 14, 1986, the same was done by the European Space Agency’s (ESA) Giotto spacecraft. These missions, together with the Japanese Suisei (…