Search Publications
The HR 1614 moving group is not a dissolving cluster
Casagrande, Luca; Feltzing, Sofia; Sahlholdt, Christian L. +3 more
Context. The HR 1614 is an overdensity in velocity space and has for a long time been known as an old (∼2 Gyr) and metal-rich ([Fe/H] ≈ +0.2) nearby moving group that has a dissolving open cluster origin. The existence of such old and metal-rich groups in the solar vicinity is quite unexpected since the vast majority of nearby moving groups are kn…
Tracing the Origins of the Ice Giants Through Noble Gas Isotopic Composition
Mousis, O.; Marty, B.; Mandt, K. E. +4 more
The current composition of giant planet atmospheres provides information on how such planets formed, and on the origin of the solid building blocks that contributed to their formation. Noble gas abundances and their isotope ratios are among the most valuable pieces of evidence for tracing the origin of the materials from which the giant planets fo…
Clumpiness: time-domain classification of red giant evolutionary states
Bell, Keaton J.; Hekker, Saskia; Kuszlewicz, James S.
Long, high-quality time-series data provided by previous space missions such as CoRoT and Kepler have made it possible to derive the evolutionary state of red giant stars, i.e. whether the stars are hydrogen-shell burning around an inert helium core or helium-core burning, from their individual oscillation modes. We utilize data from the Kepler mi…
Visible and near-infrared spectro-interferometric analysis of the edge-on Be star o Aquarii
Meilland, A.; Carciofi, A. C.; Domiciano de Souza, A. +11 more
Aims: We present a detailed visible and near-infrared spectro-interferometric analysis of the Be-shell star o Aquarii from quasi-contemporaneous CHARA/VEGA and VLTI/AMBER observations.
Methods: We analyzed spectro-interferometric data in the Hα (VEGA) and Brγ (AMBER) lines using models of increasing complexity: simple geometric models, k…
Mercury Dust Monitor (MDM) Onboard the Mio Orbiter of the BepiColombo Mission
Kimura, Hiroshi; Hasegawa, Sunao; Krüger, Harald +17 more
An in-situ cosmic-dust instrument called the Mercury Dust Monitor (MDM) had been developed as a part of the science payload for the Mio (Mercury Magnetospheric Orbiter, MMO) stage of the joint European Space Agency (ESA)-JAXA Mercury-exploration mission. The BepiColombo spacecraft was successfully launched by an Ariane 5 rocket on October 20, 2018…
A Year-long Superoutburst from an Ultracompact White Dwarf Binary Reveals the Importance of Donor Star Irradiation
Maccarone, T. J.; Rivera Sandoval, L. E.; Pichardo Marcano, M.
SDSS J080710+485259 is the longest-period outbursting ultracompact white dwarf binary. Its first-ever detected superoutburst started in 2018 November and lasted for a year, the longest detected so far for any short orbital period accreting white dwarf. Here we show the superoutburst duration of SDSS J080710+485259 exceeds the ∼2 month viscous time…
Time evolution of cyclotron line of Her X-1: a detailed statistical analysis including new AstroSat data
Staubert, R.; Maitra, C.; Bhattacharya, D. +1 more
The cyclotron line feature in the X-ray spectrum of the accretion-powered pulsar Her X-1 has been observed and monitored for over three decades. The line energy exhibited a slow secular decline over the period 1995-2014, with a possible (not confirmed) indication of a reversal thereafter. Recent works have shown that the temporal evolution of the …
First spectroscopic study of ionised gas emission lines in the extreme low surface brightness galaxy Malin 1
Koda, J.; Chemin, L.; Boselli, A. +7 more
Context. Malin 1 is the largest known low surface brightness (LSB) galaxy, the archetype of so-called giant LSB galaxies. The structure and origin of such galaxies are still poorly understood, especially because of the lack of high-resolution kinematics and spectroscopic data.
Aims: We use emission lines from spectroscopic observations of Mal…
The origin of X-ray emission in the gamma-ray emitting narrow-line Seyfert 1 1H 0323+342
Fabian, A. C.; Reynolds, C. S.; Pinto, C. +7 more
We present the results of X-ray spectral and timing analyses of the closest gamma-ray emitting narrow-line Seyfert 1 (γ-NLS1) galaxy, 1H 0323+342. We use observations from a recent, simultaneous XMM-Newton/NuSTAR campaign. As in radio-quiet NLS1s, the spectrum reveals a soft excess at low energies (≲2 keV) and reflection features such as a broad i…
Carina High-contrast Imaging Project for massive Stars (CHIPS). I. Methodology and proof of concept on QZ Car (≡ HD 93206)
Absil, O.; De Ridder, J.; Zinnecker, H. +13 more
Context. Massive stars like company. However, low-mass companions have remained extremely difficult to detect at angular separations (ρ) smaller than 1″ (approx. 1000-3000 au, considering the typical distance to nearby massive stars) given the large brightness contrast between the companion and the central star. Constraints on the low-mass end of …