Search Publications
Heavy Molecular and Metallic Ions in the Magnetosphere
Yamauchi, M.; Wurz, P.; Dandouras, I. +11 more
Observations and present knowledge of heavy ions with mass ≥ 27 in the magnetosphere are reviewed. There are four ultimate sources of these heavy ions: the solar wind (mainly high charge-state atomic ions), the ionosphere (mainly molecular ions), the atmospheric metal layers that originate ultimately from ablation of meteoroids and possibly space …
Using the Ca II Lines in T Tauri Stars to Infer the Abundance of Refractory Elements in the Innermost Disk Region
Herczeg, Gregory J.; Manara, Carlo F.; Venuti, Laura +5 more
We present a study of the abundance of calcium in the innermost disk of 70 T Tauri stars in the star-forming regions of Chamaeleon I, Lupus, and Orion OB1b. We use calcium as a proxy for the refractory material that reaches the inner disk. We used magnetospheric accretion models to analyze the Ca II emission lines and estimate abundances in the ac…
The Measurement of Masses of OB-type Stars from LAMOST DR5
Liu, Chao; Liu, Zhicun; Cui, Wenyuan +5 more
The measurements of masses and luminosities of massive stars play an important role in understanding the formation and evolution of their host galaxies. In this work, we present the measurement of masses and luminosities of 2946 OB-type stars, including 78 O-type stars and 2868 B-type stars, based on their stellar parameters (effective temperature…
S-process nucleosynthesis in chemically peculiar binaries
Hansen, C. J.; Kubátová, B.; Stateva, I. +4 more
Context. Around half of the heavy elements in the Universe are formed through the slow neutron capture (s-) process, which takes place in thermally pulsing asymptotic giant branch (AGB) stars with masses of 1 ‑ 6 M⊙. The nucleosynthetic imprint of the s-process can be studied by observing the material on the surface of binary barium (Ba…
In Situ Observational Evidence of the Polar Cap Arc at 1500 MLT (15MLT-PCA) Associated With the Lobe Reconnection
Shi, Run; Han, Desheng; Feng, Huiting +4 more
The polar cap arc at 1500 MLT (15MLT-PCA) has been considered as an auroral signature of the cusp's duskside boundary and been speculated to be caused by lobe reconnection. However, no observational evidence has been provided to support this speculation. Here we report a 15MLT-PCA event occurred on 29 November 2017 using multi-instrument observati…
Dissecting the planetary nebula NGC 4361 with MUSE
Walsh, J. R.; Monreal Ibero, A.; Laging, J. +1 more
Context. Optical integral field spectroscopy of planetary nebulae (PNe) offers a unique tool to explore the spatial relationships between the complex mixture of the many components (neutral, low- and high-ionisation gas, dust, and the central star) and their underlying physical conditions. Aims. The optical line and continuum emission in the very-…
X-ray Properties of Two Complementary Samples of Intermediate Seyfert Galaxies
Berton, Marco; Dalla Barba, Benedetta; Foschini, Luigi +2 more
We present the X-ray spectral analysis of two complementary sets of intermediate Seyfert galaxies (ISs). Analyzing X-ray data, we estimate the hydrogen abundance NH and test its connection with the [O III] luminosity acquired from optical observations. The results confirm the conclusions drawn in a previous study concerning the lack of a direct co…
Measuring the diffuse interstellar bands at 5780, 5797, and 6614 Å in low-resolution spectra of cool stars from LAMOST
Jiang, Bi-Wei; Luo, A. -Li; Zhao, He +7 more
Context. The limited number of high-resolution spectra of hot stars is inadequate for statistical studies of diffuse interstellar bands (DIBs). In contrast, the vast quantity of low-resolution spectroscopic surveys on cool stars holds great potential for investigating the relationship between DIBs and the known interstellar medium (ISM), as well a…
Challenges in Forecasting the Evolution of a Distorted CME Observed During the First Close Solar Orbiter Perihelion
Telloni, Daniele; Liberatore, Alessandro; Vourlidas, Angelos +11 more
Coronal Mass Ejections (CMEs), drivers of the most severe Space Weather disturbances, are often assumed to evolve self-similarly during their propagation. However, open magnetic field structures in the corona, leading to higher-speed streams in the ambient solar wind, can be source of strong distortions of the CME front. In this paper, we investig…
Resolved properties of a luminous hinge clump in the compact group of galaxies NGC 6845
Torres-Flores, Sergio; Firpo, Veronica; Mora, Marcelo D. +2 more
Context. Compact groups of galaxies are unique places where galaxy-galaxy interactions play a mayor role on the evolution of its members. These strong gravitational encounters can induce star formation bursts.
Aims: We study the properties of one of the most luminous so-called hinge clumps that is located in the compact group of galaxies NGC …