Search Publications
Stellar population of the superbubble N 206 in the LMC. II. Parameters of the OB and WR stars, and the total massive star feedback
Hamann, W. -R.; Gallagher, J. S.; Oskinova, L. M. +5 more
Context. Clusters or associations of early-type stars are often associated with a "superbubble" of hot gas. The formation of such superbubbles is caused by the feedback from massive stars. The complex N 206 in the Large Magellanic Cloud (LMC) exhibits a superbubble and a rich massive star population.
Aims: Our goal is to perform quantitative …
Heading Gaia to measure atmospheric dynamics in AGB stars
Schultheis, M.; Chiavassa, A.; Freytag, B.
Context. Asymptotic giant branch (AGB) stars are characterised by complex stellar surface dynamics that affect the measurements and amplify the uncertainties on stellar parameters. The uncertainties in observed absolute magnitudes have been found to originate mainly from uncertainties in the parallaxes. The resulting motion of the stellar photocen…
Star formation history from the cosmic infrared background anisotropies
Lagache, G.; Béthermin, M.; Maniyar, A. S.
We present a linear clustering model of cosmic infrared background (CIB) anisotropies at large scales that is used to measure the cosmic star formation rate density up to redshift 6, the effective bias of the CIB, and the mass of dark matter halos hosting dusty star-forming galaxies. This is achieved using the Planck CIB auto- and cross-power spec…
Deciphering the atmosphere of HAT-P-12b: solving discrepant results
Strassmeier, K. G.; Granzer, T.; Mallonn, M. +9 more
Context. Two independent investigations of the atmosphere of the hot Jupiter HAT-P-12b by two different groups resulted in discrepant solutions. Using broad-band photometry from the ground, one study found a flat and featureless transmission spectrum that was interpreted as gray absorption by dense cloud coverage. The second study made use of Hubb…
Coupling hydrodynamics with comoving frame radiative transfer. II. Stellar wind stratification in the high-mass X-ray binary Vela X-1
Hamann, W. -R.; Oskinova, L. M.; Sander, A. A. C. +5 more
Context. Vela X-1, a prototypical high-mass X-ray binary (HMXB), hosts a neutron star (NS) in a close orbit around an early-B supergiant donor star. Accretion of the donor star's wind onto the NS powers its strong X-ray luminosity. To understand the physics of HMXBs, detailed knowledge about the donor star winds is required.
Aims: To gain a r…
Enhancing SDO/HMI images using deep learning
Asensio Ramos, A.; Díaz Baso, C. J.
Context. The Helioseismic and Magnetic Imager (HMI) provides continuum images and magnetograms with a cadence better than one per minute. It has been continuously observing the Sun 24 h a day for the past 7 yr. The trade-off between full disk observations and spatial resolution means that HMI is not adequate for analyzing the smallest-scale events…
Lyman-continuum leakage as dominant source of diffuse ionized gas in the Antennae galaxy
Bacon, Roland; Maseda, Michael V.; Richard, Johan +14 more
The Antennae galaxy (NGC 4038/39) is the closest major interacting galaxy system and is therefore often studied as a merger prototype. We present the first comprehensive integral field spectroscopic dataset of this system, observed with the MUSE instrument at the ESO VLT. We cover the two regions in this system which exhibit recent star formation:…
(3200) Phaethon: Bulk density from Yarkovsky drift detection
Kučáková, H.; Farnocchia, D.; Vokrouhlický, D. +8 more
Context. The recent close approach of the near-Earth asteroid (3200) Phaethon offered a rare opportunity to obtain high-quality observational data of various types.
Aims: We used the newly obtained optical light curves to improve the spin and shape model of Phaethon and to determine its surface physical properties derived by thermophysical mo…
A tale of two periods: determination of the orbital ephemeris of the super-Eddington pulsar NGC 7793 P13
Harrison, F. A.; Fabian, A. C.; Pinto, C. +10 more
We present a timing analysis of multiple XMM-Newton and NuSTAR observations of the ultra-luminous pulsar NGC 7793 P13 spread over its 65 d variability period. We use the measured pulse periods to determine the orbital ephemeris, confirm a long orbital period with Porb = 63.9+0.5-0.6 d, and find an eccentricity of e…
Revised historical solar irradiance forcing
Egorova, T.; Schmutz, W.; Rozanov, E. +5 more
Context. There is no consensus on the amplitude of historical solar forcing. The estimated magnitude of the total solar irradiance (TSI) difference between the Maunder minimum and the present time ranges from 0.1 to 6 W m-2 making the simulation of the past and future climate uncertain. One reason for this disagreement is the applied ev…