Search Publications
The Thermal Reprocessing of Reflected Radiation in the AGN Accretion Disk
Wang, Jiancheng; Zhong, Xiaogu
We present a reflected reprocessing model to study the thermal lag-wavelength relationship in the AGN accretion disk. The main radiation produced from the corona assumed with the lamppost geometry on the axis of the black hole irradiates the accretion disk to affect the temperature structure via reflection processes. Considering the thermal emissi…
Contribution of Binary Stars to the Velocity Dispersion inside OB Associations with Gaia DR2 Data
Melnik, A. M.; Dambis, A. K.
We estimated the contribution of binary systems to the velocity dispersion inside OB-associations derived from Gaia DR2 proper motions. The maximum contribution to the velocity dispersion is given by the systems with the period of revolution of $P = 5.9$ yr whose components shift by a distance of about the diameter of the system during the base-li…
M dwarf spectral indices at moderate resolution: accurate Teff and [Fe/H] for 178 southern stars
Lorenzo-Oliveira, Diego; Costa-Almeida, Ellen; Porto de Mello, Gustavo F. +2 more
We present a spectroscopic and photometric calibration to derive effective temperatures Teff and metallicities [Fe/H] for M dwarfs, based on a principal component analysis (PCA) of 147 spectral indices measured off moderate resolution (R~11 000), high S/N (>100) spectra in the λλ 8390-8834 region, plus the J-H colour. Internal uncert…
Étude des signatures aqueuses martiennes par spectroscopie infrarouge : des nuages à l'altération des régions polaires
Stcherbinine, Aurélien
Study of Martian aqueous signature through infrared spectroscopy: from clouds to polar regions alteration
On Mars, the major infrared signature of the surface consists of a broad absorption band at 3 µm. It is mainly associated with the presence of H2O molecules or –OH groups and provides insight about the presence of water ice and the hydrat…Machine Learning applied to Lunar Data to Characterize Potential Sites for Future Science, Mobile Exploration, Utilization, lunar Bases and Moon Villages.
Foing, Bernard; den Heijer, Daniël
The lunar south pole is of particular interest to researchers because of its unique geographical features. It contains craters where the near-constant sunlight does not reach the interior. These craters are of enormous importance in the process of human exploration of the moon.This research aims to develop an identification algorithm applied to LR…
Analytical study of the newly discovered open cluster Gulliver 1
Tadross, A. L.; Ismail, M. N.; Elhosseiny, Eslam G. +3 more
New observations and transit solutions of the inflated exoplanets HAT-P-40b and HAT-P-51b
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P.
We present high-precision photometric observations of the transiting exoplanets HAT-P-40b and HAT-P-51b by the Rozhen 2-m telescope. The newly-observed transit of HAT-P-40b is the first one with a complete curve. The orbital periods of the two targets were improved. We modeled the observed transits and found bigger stellar radii than those derived…
New insight into the formation mechanism of the energetic particle reservoirs in the heliosphere
He, H. -Q.
The concept of energetic particle reservoirs, essentially based on the assumption of the presence of outer reflecting boundaries/magnetic mirrors or diffusion barriers (deterministic) rather than on the effect of particle diffusive propagation (stochastic) in magnetic turbulence, has been used for decades to describe the space-extended decay phase…
GSC 03588-09315 is a low-amplitude delta Scuti variable
Boyd, D.; Walker, G.; Lloyd, Ch. +3 more
Time-series observations of GSC 03588-09315 show it is a very low amplitude, multiperiodic delta Scuti variable at the limit of detectability. Five frequencies have been identified at 13.86819(24), 8.10026(79), 5.01966(79), 11.67281(55) and 8.17490(59) c/d with amplitudes of 10, 5, 5, 4, and 3 mmag respectively. The spectral energy distribution of…
Quantitative Assessment of Protons During the Solar Proton Events of September 2017
Pandya, Megha; Bhaskara, Veenadhari
We present multi-spacecraft observations of the proton fluxes spanning from 1.5 to 433 MeV for the largest solar proton event of solar cycle 24, i.e., September 7 and 10, 2017. In September 2017, M5.5 flare on September 4, X9.3 flare on September 6 and X8.2 flare on September 10 gave rise to solar proton event when observed by near-Earth spacecraf…