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Connections between central intensity ratio and hot gas properties of early-type galaxies
Ravikumar, C. D.; Vinod, K. T.; Baheeja, C.
We report strong connections between central intensity ratio (CIR) and hot gas properties of Early-type galaxies (ETGs) in the nearby ($D\lt 30\, \mathrm{Mpc}$) Universe. We find new strong correlations between (optical) CIR and X-ray gas luminosity (LX, GAS) as well as X-ray gas temperature (TGAS). These correlations suggest…
Direct imaging and dynamical mass of a benchmark T-type brown dwarf companion to HD 167665
Lutz, D.; Genzel, R.; Sturm, E. +111 more
Context. A low-mass companion potentially in the brown dwarf mass regime was discovered on a ~12 yr orbit (~5.5 au) around HD 167665 using radial velocity (RV) monitoring. Joint RV–astrometry analyses confirmed that HD 167665B is a brown dwarf with precisions on the measured mass of ~4–9%. Brown dwarf companions with measured mass and luminosity a…
Decoding the thermal history of the merging cluster Cygnus A
Simionescu, A.; Wise, M. W.; de Vries, M. N. +1 more
We report on a detailed spatial and spectral analysis of the large-scale X-ray emission from the merging cluster Cygnus A. We use 2.2 Ms Chandra and 40 ks XMM-Newton archival data sets to determine the thermodynamic properties of the intracluster gas in the merger region between the two subclusters in the system. These profiles exhibit temperature…
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…