Search Publications
ALMA observations of CO isotopologues towards six obscured post-asymptotic giant branch stars
Olofsson, H.; Sahai, R.; Sánchez Contreras, C. +13 more
Context. Low- and intermediate-mass stars evolve through the asymptotic giant branch (AGB) when an efficient mass-loss process removes a significant fraction of their initial mass. For most sources, this mass-loss process relies on the interplay between convection, stellar pulsations, and dust formation. However, predicting the mass-loss history o…
The lithium-rich giant stars puzzle: New observational trends for a general-mass-loss scenario
de la Reza, R.
The existence of one percent of lithium-rich giant stars among normal, lithium-poor giant stars continues to be poorly explained. By merging two catalogues – one containing 10,535 lithium-rich giant stars with lithium abundances ranging from 1.5 to 4.9 dex, and the other detecting infrared sources – we have found 421 clump giant stars and 196 firs…
Near-ultraviolet absorption distribution of primitive asteroids from photometric surveys: II. Collisional families
Tatsumi, Eri; Vilas, Faith; de León, Julia +5 more
Context. Primitive asteroids consisting of mainly phyllosilicates and opaque minerals have great variation at near-ultraviolet (NUV) wavelengths (0.35–0.5 µm). The absorption in NUV could be indicative of phyllosilicates that reflect their formation environments such as the distribution of water, temperature, and pressure. The asteroid colli…
Insights into the origins of Phobos and Deimos based on a spectral comparison with small bodies and Martian materials
Fornasier, S.; Doressoundiram, A.; Mahlke, M. +4 more
Context. The origins of Phobos and Deimos are highly debated, and several distinct hypotheses have been put forth. The two most widely accepted theories are that (1) the two moons were created by a giant impact in analogy to the Earth-Moon system, whereby a debris disk was formed that then formed the two moons by accretion; and that (2) the moons …
Imaging detection of the inner dust belt and the four exoplanets in the HR 8799 system with JWST's MIRI coronagraph
Henning, Thomas; Güdel, Manuel; Colina, Luis +35 more
Context. The MIRI instrument on board JWST is now offering high-contrast imaging capacity at mid-IR wavelengths, thereby opening a completely new field of investigation for characterizing young exoplanetary systems.
Aims: The multiplanet system HR 8799 is the first target observed with MIRI's coronagraph as part of the MIRI-EC Guaranteed Time…
Establishing a mass-loss rate relation for red supergiants in the Large Magellanic Cloud
Zapartas, E.; Munoz-Sanchez, G.; de Wit, S. +3 more
Context. The high mass-loss rates of red supergiants (RSGs) drastically affect their evolution and final fate, but their mass-loss mechanism remains poorly understood. Various empirical prescriptions scaled with luminosity have been derived in the literature, yielding results with a dispersion of two to three orders of magnitude.
Aims: We det…
The accretion burst of the massive young stellar object G323.46−0.08
Matter, A.; Eislöffel, J.; Stecklum, B. +10 more
Context. Accretion bursts from low-mass young stellar objects (YSOs) have been known for many decades. In recent years, the first accretion bursts of massive YSOs (MYSOs) have been observed. These phases of intense protostellar growth are of particular importance for studying massive star formation. Bursts of MYSOs are accompanied by flares of Cla…
Gaia FGK benchmark stars: Fundamental Teff and log g of the third version
Casamiquela, L.; Creevey, O. L.; Soubiran, C. +8 more
Context. Large spectroscopic surveys devoted to the study of the Milky Way, including Gaia, use automated pipelines to determine the atmospheric parameters of millions of stars. The Gaia FGK benchmark stars are reference stars with Teff and log 𝑔 derived through fundamental relations, independently of spectroscopy, to be used as anchors…
Effects of galaxy environment on merger fraction
White, G. J.; Małek, K.; Serjeant, S. +13 more
Aims: In this work we examine how environment influences the merger fraction, from the low density field environment to higher density groups and clusters. We also study how the properties of a group or cluster, as well as the position of a galaxy in the group or cluster, influences the merger fraction.
Methods: We identified galaxy grou…
Chemical abundances and deviations from the solar S/O ratio in the gas-phase interstellar medium of galaxies based on infrared emission lines
Pérez-Díaz, Borja; Pérez-Montero, Enrique; Fernández-Ontiveros, Juan A. +3 more
Context. The infrared (IR) range is extremely useful in the context of chemical abundance studies of the gas-phase interstellar medium (ISM) due to the large variety of ionic species traced in this regime, the negligible effects from dust attenuation or temperature stratification, and the amount of data that has been and will be released in the co…