Search Publications
Cometary Nuclei—From Giotto to Rosetta
Keller, Horst Uwe; Kührt, Ekkehard
We will briefly recapitulate the beginning of modern cometary physic. Then we will assess the results of the cometary flyby missions previous to ESA's Rosetta rendezvous with comet 67P/Churyumov-Gerasimenko. Emphasis is given to the physical properties of cometary nuclei. We will relate the results of the Rosetta mission to those of the flybys. A …
X-ray flares from the stellar tidal disruption by a candidate supermassive black hole binary
Shu, Xinwen; Jiang, Ning; Li, Shuo +8 more
Optical transient surveys have led to the discovery of dozens of stellar tidal disruption events (TDEs) by massive black hole in the centers of galaxies. Despite extensive searches, X-ray follow-up observations have produced no or only weak X-ray detections in most of them. Here we report the discovery of delayed X-ray brightening around 140 days …
The compact triply eclipsing triple star TIC 209409435 discovered with TESS
Huang, X.; Mitnyan, T.; Pál, A. +9 more
We report the discovery in TESS Sectors 3 and 4 of a compact triply eclipsing triple star system. TIC 209409435 is a previously unknown eclipsing binary with a period of 5.717 d, and the presence of a third star in an outer eccentric orbit of 121.872-d period was found from two sets of third-body eclipses and from eclipse timing variations. The la…
The discovery of radio halos in the frontier fields clusters Abell S1063 and Abell 370
Churazov, E.; Zitrin, A.; Lovisari, L. +13 more
Context. Massive merging galaxy clusters often host diffuse megaparsec-scale radio synchrotron emission. This emission originates from relativistic electrons in the ionized intracluster medium. An important question is how these synchrotron emitting relativistic electrons are accelerated.
Aims: Our aim is to search for diffuse emission in the…
Detection of the Strongest Magnetic Field in a Sunspot Light Bridge
Lagg, Andreas; Solanki, Sami K.; Castellanos Durán, J. S. +1 more
Traditionally, the strongest magnetic fields on the Sun have been measured in sunspot umbrae. More recently, however, much stronger fields have been measured at the ends of penumbral filaments carrying the Evershed and counter-Evershed flows. Superstrong fields have also been reported within a light bridge separating two umbrae of opposite polarit…
Discovery of a hot ultramassive rapidly rotating DBA white dwarf
Postnov, K. A.; Blinnikov, S. I.; Dodin, A. V. +6 more
We report the discovery of a nearby massive white dwarf with He-H atmosphere. The white dwarf is located at a distance of 74.5 ± 0.9-=pc. Its radius, mass, effective temperature, H/He ratio, and age are R = 2500 ± 100-=km, M = 1.33 ± 0.01-= $\rm M_{\odot }$ , Teff = 31-=200 ± 1200-=K, H/He ∼ 0.1, and 330 ± 40-=Myr, respectively. The obs…
Detailed chemical compositions of planet-hosting stars - I. Exploration of possible planet signatures
Spina, L.; Yong, D.; Asplund, M. +5 more
We present a line-by-line differential analysis of a sample of 16 planet-hosting stars and 68 comparison stars using high-resolution, high signal-to-noise ratio spectra gathered using Keck. We obtained accurate stellar parameters and high-precision relative chemical abundances with average uncertainties in Teff, log g, [Fe/H], and [X/H]…
On the AGN Nature of Two UV-bright Sources at zspec ∼ 5.5 in the CANDELS Fields: An Update on the AGN Space Density at M1450 ∼ -22.5
Dickinson, M.; Fiore, F.; Grazian, A. +8 more
It is widespread opinion that hydrogen reionization is mainly driven by primeval star-forming galaxies, with high-z active galactic nuclei (AGNs) having a minor role. Recent observations, however, challenge this notion, indicating a number of issues related to a galaxy-driven reionization scenario. We provide here an updated assessment of the spac…
A census of coronal mass ejections on solar-like stars
Lammer, H.; Guenther, E. W.; Kriskovics, L. +8 more
Coronal mass ejections (CMEs) may have major importance for planetary and stellar evolution. Stellar CME parameters, such as mass and velocity, have yet not been determined statistically. So far only a handful of stellar CMEs has been detected mainly on dMe stars using spectroscopic observations. We therefore aim for a statistical determination of…
Delay Time Distributions of Type Ia Supernovae from Galaxy and Cosmic Star Formation Histories
Pacifici, Camilla; Graur, Or; Strolger, Louis-Gregory +2 more
We present analytical reconstructions of SN Ia delay time distributions (DTDs) by way of two independent methods: by a Markov Chain Monte Carlo best-fit technique comparing the volumetric SN Ia rate history to today's compendium cosmic star formation history, and second through a maximum likelihood analysis of the star formation rate histories of …