Search Publications
Evidence for a TDE origin of the radio transient Cygnus A-2
Reynolds, C. S.; Rowlinson, A.; Siemiginowska, A. +3 more
In 2015, a radio transient named Cygnus A-2 was discovered in Cygnus A with the Very Large Array. Because of its radio brightness (νFν ≈ 6 × 1039 erg s-1), this transient likely represents a secondary black hole in orbit around the active galactic nucleus. Using Chandra ACIS observations from 2015 to 2017, we have …
The GALAH survey: unresolved triple Sun-like stars discovered by the Gaia mission
Lewis, Geraint F.; Ting, Yuan-Sen; Buder, Sven +17 more
The latest Gaia data release enables us to accurately identify stars that are more luminous than would be expected on the basis of their spectral type and distance. During an investigation of the 329 best solar twin candidates uncovered among the spectra acquired by the GALAH survey, we identified 64 such overluminous stars. In order to investigat…
Relativistic Fe Kα line in the composite X-ray spectra of radio-loud active galactic nuclei
Jin, Chichuan; Liu, Zhu; Yuan, Weimin +1 more
While a broad Fe Kα emission line is generally found in the X-ray spectra of radio quiet (RQ) active galactic nuclei (AGNs), this feature, commonly thought to be broadened by the relativistic effects near the central black hole, appears to be rare in their radio loud (RL) counterparts. In this paper, we carry out a detailed study of the ensemble p…
The 3XMM/SDSS Stripe 82 Galaxy Cluster Survey - II. X-ray and optical properties of the cluster sample
Plat, Adèle; Márquez, Isabel; Durret, Florence +3 more
We present X-ray and optical properties of the optically confirmed galaxy cluster sample from the 3XMM/SDSS Stripe 82 cluster survey. The sample includes 54 galaxy clusters in the redshift range of 0.05-1.2, with a median redshift of 0.36. We first present the X-ray temperature and luminosity measurements that are used to investigate the X-ray lum…
Evolution of the disc atmosphere in the X-ray binary MXB 1659-298, during its 2015-17 outburst
Degenaar, N.; Bianchi, S.; Ponti, G. +3 more
We report on the evolution of the X-ray emission of the accreting neutron star (NS) low-mass X-ray binary (LMXB), MXB 1659-298, during its most recent outburst in 2015-17. We detected 60 absorption lines during the soft state (of which 21 at more than 3σ), that disappeared in the hard state (e.g. the Fe XXV and Fe XXVI lines). The absorbing plasma…
An analysis of binary microlensing event OGLE-2015-BLG-0060
Bennett, D. P.; Soszyński, I.; Udalski, A. +79 more
We present the analysis of stellar binary microlensing event OGLE-2015-BLG-0060 based on observations obtained from 13 different telescopes. Intensive coverage of the anomalous parts of the light curve was achieved by automated follow-up observations from the robotic telescopes of the Las Cumbres Observatory. We show that, for the first time, all …
A method to calculate gravitational accelerations within discrete localized regions in the Milky Way
Kipper, Rain; Tenjes, Peeter; Tempel, Elmo
We present a method to calculate gravitational potential gradients within regions containing few 10s of thousands stars with known phase space coordinates. The central idea of the method is to calculate orbital arcs for each star within a given region for a certain parametrized potential (gravitational acceleration) and to assume that position of …
The footprint of cometary dust analogues - II. Morphology as a tracer of tensile strength and application to dust collection by the Rosetta spacecraft
Blum, J.; Gundlach, B.; Dominik, C. +6 more
The structure of cometary dust is a tracer of growth processes in the formation of planetesimals. Instrumentation on board the Rosetta mission to comet 67P/Churyumov-Gerasimenko captured dust particles and analysed them in situ. However, these deposits are a product of a collision within the instrument. We conducted laboratory experiments with com…
Clumpy dust rings around non-accreting young stars
Relles, Howard; Scholz, Aleks; Eislöffel, Jochen +3 more
We investigate four young, but non-accreting, very low mass stars in Orion, which show irregular eclipses by circumstellar dust. The eclipses are not recurring periodically, are variable in depth, lack a flat bottom, and their duration is comparable to the typical time-scale between eclipses. The dimming is associated with reddening consistent wit…
Multiwavelength observations of the triple-peaked AGN Mrk 622
Jiménez-Bailón, E.; Binette, L.; González-Martín, O. +8 more
A detailed multiwavelength study of the properties of the triple-peaked active galactic nucleus (AGN) Mrk 622 showing different aspects of the nuclear emission region is presented. Radio, near- and mid-infrared, optical, and X-ray data have been considered for the analysis. In the optical, the WHAN diagnostic diagrams show that the three nuclear p…