Search Publications
Implications of time-dependent molecular chemistry in metal-poor dwarf stars
Ludwig, H. -G.; Deshmukh, S. A.
Context. Binary molecules such as CO, OH, CH, CN, and C2 are often used as abundance indicators in stars. These species are usually assumed to be formed in chemical equilibrium. The time-dependent effects of hydrodynamics can affect the formation and dissociation of these species and may lead to deviations from chemical equilibrium.
Infrared He I 10830 Å, ultra-violet Ca II, and Mg II chromosphere emissions in the spectra of classical Cepheid X Cyg
Korotin, S. A.; Andrievsky, S. M.; Kovtyukh, V. V.
Aims: In a previous publication, we reported the first detection of emission in the infrared (IR) triplet at 10 830 Å in the spectra of the classical Cepheid X Cyg. Emission is detectable at phases from approximately 0.25 to 0.90. We present and discuss further information on the chromosphere activity of this star, namely International Ultrav…
MoBiDICT: New 3D static models of close synchronised binaries in hydrostatic equilibrium
Dupret, M. -A.; Fellay, L.
Context. In close binary systems, tidal interactions and rotational effects can strongly influence stellar evolution as a result of mass transfer and common envelope phases. These aspects can only be treated following improvements of theoretical models to take into account the breaking of spherical symmetry occurring in close binaries. Current mod…
TDCOSMO. XI. New lensing galaxy redshift and velocity dispersion measurements from Keck spectroscopy of eight lensed quasar systems
Treu, T.; Fassnacht, C. D.; Spiniello, C. +2 more
We have measured the redshifts and single-aperture velocity dispersions of eight lens galaxies using the data collected by the Echellette Spectrograph and Imager (ESI) and Low Resolution Imaging Spectrometer (LRIS) at W.M. Keck observatory on different observing nights spread over three years (2018-2020). These results, combined with other ancilla…
LBT-MODS spectroscopy of high-redshift candidates in the Chandra J1030 field. A newly discovered z ∼ 2.8 large-scale structure
Comastri, Andrea; Signorini, Matilde; Vito, Fabio +13 more
We present the results of a spectroscopic campaign with the Multi-Object Double Spectrograph (MODS) instrument mounted on the Large Binocular Telescope (LBT), aimed at obtaining a spectroscopic redshift for seven Chandra J1030 sources with a photometric redshift ≥2.7 and optical magnitude rAB = [24.5 − 26.5]. We obtained a spectroscopic…
CHEX-MATE: X-ray absorption and molecular content of the interstellar medium toward galaxy clusters
Pointecouteau, E.; Pratt, G. W.; Rossetti, M. +14 more
The X-ray spectrum of extragalactic sources, such as galaxy clusters, is affected by the photo-absorption of various components of the Galactic interstellar medium (ISM). The resulting spectral distortion contributes to the systematics of cluster temperature measurements. It essentially depends on the neutral (atomic+molecular) Galactic hydrogen d…
A machine learning algorithm for reliably predicting active galactic nucleus absorbing column densities
Ajello, M.; Marchesi, S.; Torres-Albà, N. +4 more
We present a new method for predicting the line-of-sight column density (NH) values of active galactic nuclei (AGN) based on mid-infrared (MIR), soft X-ray, and hard X-ray data. We developed a multiple linear regression machine learning algorithm trained with WISE colors, Swift-BAT count rates, soft X-ray hardness ratios, and an MIR-sof…
Star-forming brightest cluster galaxies at z ∼ 0.4 in KiDS. Further studies of cold gas and stellar properties
Castignani, G.; Moscardini, L.; Radovich, M. +10 more
Brightest cluster galaxies (BCGs) at the centers of clusters are among the most massive galaxies in the Universe. Their star formation history and stellar mass assembly are highly debated. Recent studies suggest the presence of an emerging population of intermediate-z star-forming and gas-rich BCGs, whose molecular gas reservoirs that feed star fo…
Unveiling the chemical fingerprint of phosphorus-rich stars. I. In the infrared region of APOGEE-2
Masseron, Thomas; Hayes, Christian R.; Pignatari, Marco +4 more
Context The origin of phosphorus, one of the essential elements for life on Earth, is currently unknown. Prevalent models of Galactic chemical evolution (GCE) systematically underestimate the amount of P compared to observations, especially at low metallicities. The recently discovered P-rich ([P/Fe] ≳ 1.2 dex) and metal-poor ([Fe/H] ≃ −1.0 dex) g…
Chasing extreme planetary architectures. I. HD 196885 Ab, a super-Jupiter dancing with two stars?
Bouchy, F.; Kervella, P.; Udry, S. +21 more
Context. Planet(s) in binaries are unique architectures for testing predictions of planetary formation and evolution theories in very hostile environments. Their presence in such a highly perturbed region poses a clear challenge from the early phase of planetesimals accretion to the dynamical evolution and stability through a very long period of t…