Search Publications
The prototypical major cluster merger Abell 754: I. Calibration of MeerKAT data and radio/X-ray spectral mapping of the cluster
Brunetti, G.; Gastaldello, F.; Kale, R. +6 more
Context. Abell 754 is a rich galaxy cluster at z = 0.0543 and is considered the prototype of a major cluster merger. As many dynamically unrelaxed systems, it hosts diffuse radio emission on megaparsec-scales. Extended synchrotron sources in the intra-cluster medium (ICM) are commonly interpreted as evidence that a fraction of the gravitational en…
Infrared surface brightness technique applied to RR Lyrae stars from the solar neighborhood
Gieren, Wolfgang; Pietrzyński, Grzegorz; Haas, Martin +9 more
Context. The Baade-Wesselink (BW) method, also known as the pulsation parallax method, allows us to estimate distances to individual pulsating stars. Accurate geometric parallaxes obtained by the Gaia mission serve us in the calibration of the method and in the determination of its precision. This method also provides a way of determining mean rad…
First comparative exoplanetology within a transiting multi-planet system: Comparing the atmospheres of V1298 Tau b and c
Fortney, Jonathan J.; Désert, Jean-Michel; Line, Michael R. +13 more
The V1298 Tau system is a multi-planet system that provides the opportunity to perform comparative exoplanetology between planets orbiting the same star. Because of its young age (20–30 Myr), this system also provides the opportunity to compare the planet's early evolutionary properties, right after their formation. We present the first atmospheri…
Machine learning applications in studies of the physical properties of active galactic nuclei based on photometric observations
Ackermann, Markus; Kowalski, Marek; Mechbal, Sarah
Context. We investigate the physical nature of active galactic nuclei (AGNs) using machine learning (ML) tools.
Aims: We show that the redshift, z, bolometric luminosity, LBol, central mass of the supermassive black hole (SMBH), MBH, Eddington ratio, λEdd, and AGN class (obscured or unobscured) can be reconstr…
Ejection and dynamics of aggregates in the coma of comet 67P/Churyumov-Gerasimenko
Agarwal, J.; Lemos, P.; Marschall, R. +1 more
Context. The process of gas-driven ejection of refractory materials from cometary surfaces continues to pose a challenging question in cometary science. The activity modeling of comet 67P/Churyumov-Gerasimenko, based on data from the Rosetta mission, has significantly enhanced our comprehension of cometary activity. But thermophysical models have …
The outflowing ionised gas of I Zw 1 observed by HST COS
Brandt, W. N.; Kriss, G. A.; Costantini, E. +8 more
Aims: We present an analysis of the Hubble Space Telescope Cosmic Origins Spectrograph spectrum of I Zw 1 aiming to probe the absorbing medium associated with the active galactic nucleus (AGN).
Methods: We fitted the emission spectrum and performed spectral analysis of the identified absorption features to derive the corresponding ionic …
Dark matter in the Milky Way: Measurements up to 3 kpc from the Galactic plane above the Sun
Reylé, C.; Robin, A. C.; Bienaymé, O. +1 more
We probe the gravitational force perpendicular to the Galactic plane at the position of the Sun based on a sample of red giants, with measurements taken from the DR3 Gaia catalogue. Measurements far out of the Galactic plane up to 3.5 kpc allow us to determine directly the total mass density, where dark matter is dominant and the stellar and gas d…
Gas metallicity of ram-pressure-stripped galaxies at intermediate redshifts with MUSE data
Werle, A.; Poggianti, B.; Gullieuszik, M. +5 more
Extraplanar tails of ionized-stripped gas, extending up to several tens of kiloparsecs beyond the stellar disk, are often observed in ram-pressure-stripped (RPS) galaxies in low-redshift clusters. Recent studies have also identified similar tails at high redshifts, and we present here the first analysis of the chemical composition of such tails be…
Diffuse interstellar bands in Gaia DR3 RVS spectra. New measurements based on machine learning
Schultheis, M.; Zwitter, T.; Zhao, H. +1 more
Diffuse interstellar bands (DIBs) are weak and broad interstellar absorption features in astronomical spectra that originate from unknown molecules. To measure DIBs in spectra of late-type stars more accurately and more efficiently, we developed a random forest model to isolate the DIB features from the stellar components. We applied this method t…
The β Pictoris b Hill sphere transit campaign. II. Searching for the signatures of the β Pictoris exoplanets through time delay analysis of the δ Scuti pulsations
Mamajek, Eric; Stevenson, Kevin B.; Kalas, Paul +34 more
The β Pictoris system is the closest known stellar system with directly detected gas giant planets, an edge-on circumstellar disc, and evidence of falling sublimating bodies and transiting exocomets. The inner planet, β Pictoris c, has also been indirectly detected with radial velocity (RV) measurements. The star is a known δ Scuti pulsator, and t…