Search Publications
Seismic solar models from Ledoux discriminant inversions
Buldgen, G.; Eggenberger, P.; Christensen-Dalsgaard, J. +6 more
Context. The Sun constitutes an excellent laboratory of fundamental physics. With the advent of helioseismology, we were able to probe its internal layers with unprecendented precision and thoroughness. However, the current state of solar modelling is still stained by tedious issues. One of these central problems is related to the disagreement bet…
How faculae and network relate to sunspots, and the implications for solar and stellar brightness variations
Solanki, S. K.; Yeo, K. L.; Krivova, N. A.
Context. How global faculae and network coverage relates to that of sunspots is relevant to the brightness variations of the Sun and Sun-like stars.
Aims: We aim to extend and improve on earlier studies that established that the facular-to-sunspot-area ratio diminishes with total sunspot coverage.
Methods: Chromospheric indices and the t…
Stellar wind models of central stars of planetary nebulae
Krtička, J.; Kubát, J.; Krtičková, I.
Context. Fast line-driven stellar winds play an important role in the evolution of planetary nebulae, even though they are relatively weak.
Aims: We provide global (unified) hot star wind models of central stars of planetary nebulae. The models predict wind structure including the mass-loss rates, terminal velocities, and emergent fluxes from…
X-ray and γ-ray orbital variability from the γ-ray binary HESS J1832-093
Reimer, O.; Martí-Devesa, G.
Context.γ-ray binaries are systems composed of a massive star and a compact object whose interaction leads to particle acceleration up to relativistic energies. In the last fifteen years, a few binaries have been found to emit at high energies, but their number is still low. The TeV source HESS J1832-093 has been proposed as a binary candidate, al…
Thermal properties of large main-belt asteroids observed by Herschel PACS
Marton, G.; Müller, T. G.; Kiss, C. +11 more
Non-resolved thermal infrared observations enable studies of thermal and physical properties of asteroids via thermo-physical models provided the shape and rotational properties of the target are well determined. We used calibration-programme Herschel PACS data (70, 100, 160 µm) and state-of-the-art shape models derived from adaptive-optics …
Estimating black hole masses: Accretion disk fitting versus reverberation mapping and single epoch
Celotti, Annalisa; Ghisellini, Gabriele; Sbarrato, Tullia +1 more
We selected a sample of 28 Type 1 active galactic nuclei for which a black hole mass has been inferred using the reverberation mapping technique and single epoch scaling relations. All 28 sources show clear evidence of the "Big Blue Bump" in the optical-UV band whose emission is produced by an accretion disk (AD) around a supermassive black hole. …
Very long baseline interferometry imaging of the advancing ejecta in the first gamma-ray nova V407 Cygni
Munari, U.; Cheung, C. C.; Giroletti, M. +7 more
Context. In 2010 March, the Large Area Telescope on board Fermi revealed a transient gamma-ray source that is positionally coincident with the optical nova in the symbiotic binary, V407 Cyg. This event marked the first discovery of gamma-ray emission from a nova.
Aims: We aim to obtain resolved radio imaging of the material involved in the no…
The OTELO survey. Nature and mass-metallicity relation for Hα emitters at z ∼ 0.4
Gallego, Jesús; Sánchez-Portal, Miguel; Pintos-Castro, Irene +14 more
Context. A sample of low-mass Hα emission line sources at z ∼ 0.4 was studied in the context of the mass-metallicty relation (MZR) and its possible evolution. We drew our sample from the OSIRIS Tunable Emission Line Object (OTELO) survey, which exploits the red tunable filter of OSIRIS at the Gran Telescopio Canarias to perform a blind narrow-band…
Evidence for a rapid decrease of Pluto's atmospheric pressure revealed by a stellar occultation in 2019
Kasaba, Y.; Ohsawa, R.; Kagitani, M. +4 more
We report observations of a stellar occultation by Pluto on 2019 July 17. A single-chord high-speed (time resolution = 2 s) photometry dataset was obtained with a CMOS camera mounted on the Tohoku University 60 cm telescope (Haleakala, Hawaii). The occultation light curve is satisfactorily fitted to an existing atmospheric model of Pluto. We find …
MUSE observations towards the lensing cluster A2744: Intersection between the LBG and LAE populations at z ∼ 3-7
Schaerer, D.; Laporte, N.; Bauer, F. E. +14 more
We present a study of the intersection between the populations of star forming galaxies selected as either Lyman break galaxies (LBGs) or Lyman-alpha emitters (LAEs) in the redshift range 2.9 - 6.7 and within the same volume of universe sampled by the Multi-Unit Spectroscopic Explorer (MUSE) behind the Hubble Frontier Fields lensing cluster A2744.…