Search Publications
A detailed view on the circumstellar environment of the M-type AGB star EP Aquarii. I. High-resolution ALMA and SPHERE observations
Decin, Leen; Montargès, Miguel; Millar, Tom J. +3 more
Cool evolved stars are known to be significant contributors to the enrichment of the interstellar medium through their dense and dusty stellar winds. High resolution observations of these outflows have shown them to possess high degrees of morphological complexity. We observed the asymptotic giant branch (AGB) star EP Aquarii with ALMA in band 6 a…
NLTE modeling and spectroscopically derived abundances of lithium and beryllium for classical nova ejecta
Shore, Steven N.; De Gennaro Aquino, Ivan
Context. Extreme super-solar abundances of lithium and beryllium have been reported in recent years for classical novae based on absorption lines in ultraviolet and optical spectra during the optically thick stages, but these findings have not been compared with spectrum syntheses of the ejecta.
Aims: We present a grid of nova ejecta models c…
Characterization of the umbra-penumbra boundary by the vertical component of the magnetic field. Analysis of ground-based data from the GREGOR Infrared Spectrograph
Bello González, N.; Schlichenmaier, R.; Lindner, P.
Context. The vertical component of the magnetic field was found to reach a constant value at the boundary between penumbra and umbra of stable sunspots in a recent statistical study of Hinode/SP data. This finding has profound implications as it can serve as a criterion to distinguish between fundamentally different magneto-convective modes operat…
Mechanochemical synthesis of aromatic infrared band carriers. The top-down chemistry of interstellar carbonaceous dust grain analogues
Engrand, C.; Dartois, E.; Charon, E. +2 more
Context. Interstellar space hosts nanometre- to micron-sized dust grains, which are responsible for the reddening of stars in the visible. The carbonaceous-rich component of these grain populations emits in infrared bands that have been observed remotely for decades with telescopes and satellites. They are a key ingredient of Galactic radiative tr…
Evolution of downflows in the transition region above a sunspot over short time-scales
Mathioudakis, M.; Krishna Prasad, S.; Nelson, C. J.
Context. Downflows with potentially super-sonic velocities have been reported to occur in the transition region above many sunspots; however, how these signatures evolve over short time-scales in both spatial and spectral terms is still unknown and requires further research.
Aims: In this article, we investigate the evolution of downflows det…
Continuation of the X-ray monitoring of Sgr A*: the increase in bright flaring rate confirmed
Mossoux, E.; Finociety, B.; Beckers, J. -M. +1 more
Context. The supermassive black hole Sagittarius A* (Sgr A*) is located at the dynamical center of the Milky Way. In a recent study of the X-ray flaring activity from Sgr A* using Chandra, XMM-Newton, and Swift observations from 1999 to 2015, it has been argued that the bright flaring rate has increased from 2014 August 31 while the faint flaring …
The XXL Survey. XLII. Detection and characterisation of the galaxy population of distant galaxy clusters in the XXL-N/VIDEO field: A tale of variety
Chiappetti, L.; Häußler, B.; Bowler, R. A. A. +16 more
Context. Distant galaxy clusters provide an effective laboratory in which to study galaxy evolution in dense environments and at early cosmic times.
Aims: We aim to identify distant galaxy clusters as extended X-ray sources that are coincident with overdensities of characteristically bright galaxies.
Methods: We used optical and near-inf…
Ammonia observations towards the Aquila Rift cloud complex
Li, Dalei; Tang, Xindi; Zhou, Jianjun +7 more
We surveyed the Aquila Rift complex including the Serpens South and W 40 regions in the NH3 (1,1) and (2,2) transitions making use of the Nanshan 26-m telescope. Our observations cover an area of ~ 1.5° × 2.2° (11.4 pc × 16.7 pc). The kinetic temperatures of the dense gas in the Aquila Rift complex obtained from NH3 (2,2)/(1,…
ALMA resolves molecular clouds in metal-poor Magellanic Bridge A
Bolatto, A. D.; Rubio, M.; Saldaño, H. P. +2 more
Context. The Magellanic Bridge is a tidal feature located between the Magellanic Clouds, containing young stars formed in situ. Its proximity allows high-resolution studies of molecular gas, dust, and star formation in a tidal low-metallicity environment.
Aims: Our goal is to characterize gas and dust emission in Magellanic Bridge A, the sour…
The unusual behavior of the young X-ray pulsar SXP 1062 during the 2019 outburst
Maitra, Chandreyee; Haberl, Frank; Doroshenko, Victor +6 more
We present the results of the first dedicated observation of the young X-ray pulsar SXP 1062 in the broad X-ray energy band obtained during its 2019 outburst with the NuSTAR and XMM-Newton observatories. The analysis of the pulse-phase averaged and phase-resolved spectra in the energy band from 0.5 to 70 keV did not reveal any evidence for the pre…