Search Publications
OGLE-GD-CEP-0516: The most metal-poor lithium-rich Galactic Cepheid
Salaris, M.; Ripepi, V.; Catanzaro, G. +1 more
Context. Classical Cepheids (DCEPs) are important astrophysical objects not only as standard candles for the determination of the cosmic distance ladder but also as a test-bed for stellar evolution theory thanks to the connection between their pulsation (periods, amplitudes) and stellar (luminosity, mass, effective temperature, metallicity) parame…
Measurement of interstellar extinction for classical T Tauri stars using far-UV H2 line fluxes
France, K.; Eislöffel, J.; Schneider, P. C. +3 more
Understanding the interstellar and potentially circumstellar extinction in the sight lines of classical T Tauri stars is an important ingredient for constructing reliable spectral energy distributions, which catalyze protoplanetary disk chemistry, for example. Therefore, some attempts of measuring AV toward individual stars have been ma…
In pursuit of precise Ca II H&K chromospheric surface fluxes: A gravity and temperature dependence
Schröder, K. -P.; Jack, D.; Rosas-Portilla, F.
The emission lines of the Ca II H&K doublet present one of the most important channels of radiative cooling for the chromospheres of cool stars. Although most other line emissions (Mg II h&k and numerous iron lines) populate the far-UV and require a very competitive space-born observing time, the Ca II H&K lines in the optical UV are easily access…
Upper limit of the solar wind protons backscattering efficiency from Comet 67P/Churyumov-Gerasimenko
Wieser, Martin; Wieser, Gabriella Stenberg; Canu-Blot, Romain
Context. Solar wind ions backscattering is a fundamental plasma-surface interaction process that may occur on all celestial bodies exposed to the solar wind and lacking a significant atmosphere or magnetosphere. Yet, observations have been limited to the regolith-covered Moon and Phobos, one of the Martian moons.
Aims: We aim to expand our kn…
A blind search for intraday gamma-ray transients with Fermi-LAT: Detections of GRB and solar emissions
Prokhorov, D. A.; Moraghan, A.
We present a search for intraday transient γ-ray signals using 15.4 yr of the Fermi Large Area Telescope data. The search is based on a recently developed variable-size sliding-time-window (VSSTW) analysis and is aimed at studying variable γ-ray emission from gamma-ray bursts (GRBs) and the Sun. We refined the algorithm for searches for transient …
An acceleration-radiation model for nonthermal flares from Sgr A*
Ponti, Gabriele; Petropoulou, Maria; Stel, Giovanni +1 more
Context. Sgr A⋆ is the electromagnetic counterpart of the accreting supermassive black hole in the Galactic center. Its emission is variable in the near-infrared (NIR) and X-ray wavelengths on short timescales (several minutes to a few hours). The NIR light curve displays red-noise variability, while the X-ray light curve exhibits brigh…
Molecular gas budget of strongly magnified low-mass star-forming galaxies at cosmic noon
Sharon, K.; Bayliss, M.; Mahler, G. +9 more
Aims. The aim of this study is to investigate the molecular gas content of strongly magnified low-mass star-forming galaxies (SFGs) around the cosmic noon period (z ∼ 2) through observations of carbon monoxide (CO) emission lines and dust continuum emission, both of which serve as tracers of molecular gas (H2). Methods. We observed 12 s…
The stellar population of a z ∼ 3.25 Lyα-emitting group associated with a damped Lyα absorber
Rafelski, Marc; Fumagalli, Michele; Fossati, Matteo +4 more
We present near-infrared observations, acquired with the Wide Field Camera 3 (WFC3) on board the Hubble Space Telescope (HST), of a Lyα-emitting double-clumped nebula at z ≈ 3.25 associated with a damped Lyα absorber (DLA). With the WFC3/F160W data we observe the stellar continuum around 3600 Å in the rest frame of a galaxy embedded in the west cl…
Distance and stellar parameter estimations of solar-like stars from the LAMOST spectroscopic survey
Luo, A. -Li; Shen, Yue-Yue
Context. The Gaia mission has opened up a new era for the precise astrometry of stars, thus revolutionizing our understanding of the Milky Way. However, beyond a few kiloparseconds from the Sun, parallax measurements become less reliable, and even within 2 kpc, there still exist stars with large uncertainties. Aims. Our aim was to determine the di…
Stellar population astrophysics with the TNG. Abundance analysis of nearby red giants and red clump stars: Combining high-resolution spectroscopy and asteroseismology
Miglio, Andrea; Bragaglia, Angela; Lucatello, Sara +4 more
Context. Asteroseismology, a powerful approach for obtaining internal structure and stellar properties, requires surface temperature and chemical composition information to determine mass and age. High-resolution spectroscopy is a valuable technique for precise stellar parameters (including surface temperature) and for an analysis of the chemical …