Search Publications
Chemical abundances of 20 barium stars from the OHP spectra
Shi, Jianrong; Zhao, Gang; Zhao, Jingkun +7 more
Based on the high resolution and high signal-to-noise spectra, we derived the chemical abundances of 20 elements for 20 barium (Ba-) stars. For the first time, the detailed abundances of four sample stars, namely HD 92482, HD 150430, HD 151101, and HD 177304 have been analysed. Additionally, Ba element abundance has been measured using high-resolu…
X-Rays from the Nearby Compact Emission-line Galaxy NGC 2366
Kaaret, Philip; Prestwich, Andrea
Luminous, compact emission-line galaxies (LCGs) are the most abundant class of confirmed Lyman continuum (LyC) emitters. An optical integral field study of the nearby LCG NGC 2366 reveals an outflow originating at the star cluster "knot B" thought to clear a channel via mechanical feedback that enables LyC escape. We observed NGC 2366 with the Cha…
Observational constraints on modified CPL models considering non-cold dark matter
Sardar, Gopal; Chakraborty, Subenoy
In the present work we consider three modified Chevallier–Polarski–Linder (CPL) models with considering non-cold dark matter in the background of homogeneous and isotropic FLRW space–time model. From the observational data set ((Pantheon+)+BAO+HST) we find that all the parameters involved in the models having equation of dark energy state ωde=ω0+ω…
Long Term CCD Photometry of the Distant Cluster NGC2419: The CMD Revisited
Arellano Ferro, A.; Muneer, S.; Yepez, M. A. +4 more
Employing VI images of NGC 2419 acquired over 17 years, light curves for most of the known variables in the field of the cluster are produced. A cluster membership analysis for about 3100 stars in the cluster field with proper motions from Gaia-DR3 revealed the presence of member stars as far as 140 pc from the cluster center and enabled the const…
A Photometric and Astrometric Study of Open Star Clusters FSR-163 and Majaess 215 Using Gaia DR3
Tadross, A. L.; Ali, Ola; Osman, A. I. +1 more
We have examined most of the astrophysical properties of the two star clusters, FSR-163 and Majaess 215, using the third data release of the Gaia space mission (Gaia DR3). We utilized the pyUPMASK method to allocate the probabilities of stars' membership candidates. Using the clusters' trigonometric parallaxes of the members with probabilities P &…
Searching for wide binary stars with non-coeval components in the northern sky
Malkov, Oleg; Kniazev, Alexey; Gorda, Stanislav
We have spectroscopically studied the last six stars in the northern sky from our preliminary list of candidates for wide non-coeval pairs, and we have found no evidence of non-coevality. Thus, considering our previous research, which found one such binary system, we confirm that our preliminary estimate of the fraction of binaries in the solar ne…
Revisiting Physical Parameters of the Benchmark Brown Dwarf LHS 6343 C through a Hubble Space Telescope/WFC3 Secondary-eclipse Observation
Montet, Benjamin T.; Gagné, Jonathan; Albert, Loïc +7 more
The LHS 6343 system consists of a resolved M-dwarf binary with an evolved, negligibly irradiated brown dwarf (BD), LHS 6343 C, orbiting the primary star. Such BD eclipsing binaries present rare and unique opportunities to calibrate substellar evolutionary and atmosphere models since mass, radius, temperature, and luminosity can be directly measure…
Observations of Water Frost on Mars With THEMIS: Application to the Presence of Brines and the Stability of (Sub)Surface Water Ice
Forget, F.; Piqueux, S.; Szantai, A. +4 more
Characterizing the exchange of water between the Martian atmosphere and the (sub)surface is a major challenge for understanding the mechanisms that regulate the water cycle. Here we present a new data set of water ice detected on the Martian surface with the Thermal Emission Imaging System (THEMIS). The detection is based on the correlation betwee…
Faint mm NIKA2 dusty star-forming galaxies: Finding the high-redshift population
Berta, S.; Aussel, H.; Adam, R. +46 more
Aims: High-redshift dusty star-forming galaxies (DSFGs) are proposed to be the progenitors of massive quiescent galaxies arising at cosmic noon, providing a crucial insight into the formation, assembly, and early quenching of massive galaxies in the early Universe. However, their high redshift combined with high dust obscuration adds signific…
Comprehensive Characterization of the Dynamics of Two Coronal Mass Ejections in the Outer Corona
Nieves-Chinchilla, Teresa; Cremades, Hebe; Balmaceda, Laura +1 more
Coronal mass ejections (CMEs) play a key role in determining space-weather conditions. Therefore, it is important to understand their evolution throughout the heliosphere. In this work, we carefully analyze the evolution of two kinematically different CMEs that erupted on 16 June 2010 and 14 June 2011, in a range of heliospheric distances of appro…