Search Publications
Molecular remnant of Nova 1670 (CK Vulpeculae). II. A three-dimensional view of the gas distribution and velocity field
Menten, K. M.; Bujarrabal, V.; Steffen, W. +3 more
CK Vul is the remnant of an energetic eruption known as Nova 1670 that is thought to be caused by a stellar merger. The remnant is composed of (1) a large hourglass nebula of recombining gas (of 71'' in size), very similar to some classical planetary and pre-planetary nebulae (PPNe), and (2) a much smaller and cooler inner remnant that is prominen…
A dearth of young and bright massive stars in the Small Magellanic Cloud
Menten, K. M.; Crowther, P. A.; de Koter, A. +7 more
Context. Massive star evolution at low metallicity is closely connected to many fields in high-redshift astrophysics, but is poorly understood so far. Because of its metallicity of ∼0.2 Z⊙, its proximity, and because it is currently forming stars, the Small Magellanic Cloud (SMC) is a unique laboratory in which to study metal-poor massi…
The (im)possibility of strong chemical tagging
Castro-Ginard, A.; Casamiquela, L.; Anders, F. +1 more
Context. The possibility of identifying co-natal stars that have dispersed into the Galactic disc based on chemistry alone is called strong chemical tagging. It has been debated for a long time whether this is indeed feasible; it holds the promise of reconstructing the detailed star formation history of a large fraction of stars in the Galactic di…
Radial structure and formation of the Milky Way disc
Katz, D.; Haywood, M.; Gómez, A. +2 more
Context. The formation of the Galactic disc is an enthusiastically debated issue. Numerous studies and models seek to identify the dominant physical process(es) that shaped its observed properties; for example, satellite accretion, starburst, quenching, gas infall, and stellar radial migration.
Aims: Taking advantage of the improved coverage …
The Tarantula Massive Binary Monitoring. V. R 144: a wind-eclipsing binary with a total mass ≳140 M⊙
Howarth, I. D.; Crowther, P. A.; de Mink, S. E. +21 more
Context. The evolution of the most massive stars and their upper-mass limit remain insufficiently constrained. Very massive stars are characterized by powerful winds and spectroscopically appear as hydrogen-rich Wolf-Rayet (WR) stars on the main sequence. R 144 is the visually brightest WR star in the Large Magellanic Cloud. R 144 was reported to …
Generation of interplanetary type II radio emission
Jebaraj, I. C.; Mann, G.; Poedts, S. +4 more
Context. Coronal mass ejections (CMEs) are eruptive phenomena that can accelerate energetic particles and drive shock waves. The CME-driven shocks propagate from the low corona to interplanetary space. The radio emission that results from fast electrons energised by shock waves are called type II bursts. This radio emission can provide information…
Long-term pulse period evolution of the ultra-luminous X-ray pulsar NGC 7793 P13
Ptak, A.; Stern, D.; Fabian, A. C. +14 more
Ultra-luminous X-ray pulsars (ULXPs) provide a unique opportunity to study persistent super-Eddington accretion. Here we present the results of a long-term monitoring campaign of ULXP NGC 7793 P13, focusing on the pulse period evolution and the determination of the orbital ephemeris. Over our four year monitoring campaign with Swift, XMM-Newton, a…
Radio halos in a mass-selected sample of 75 galaxy clusters. I. Sample selection and data analysis
Brunetti, G.; Pratt, G. W.; Kale, R. +9 more
Context. Radio halos are synchrotron diffuse sources at the centre of a fraction of galaxy clusters. The study of large samples of clusters with adequate radio and X-ray data is necessary to investigate the origin of radio halos and their connection with the cluster dynamics and formation history.
Aims: The aim of this paper is to compile a w…
Relation between AGN type and host galaxy properties
Georgantopoulos, I.; Masoura, V. A.; Mountrichas, G. +1 more
We use 3213 active galactic nuclei (AGNs) from the XMM-XXL northern field to investigate the relation of AGN type with host galaxy properties. Applying a Bayesian method, we derive the hardness ratios, and through these the hydrogen column density (NH) for each source. We consider those with NH > 1021.5 cm-…
H II regions and high-mass starless clump candidates. II. Fragmentation and induced star formation at 0.025 pc scale: an ALMA continuum study
Liu, H.; Zavagno, A.; Zhang, S. +7 more
Context. The ionization feedback from H II regions modifies the properties of high-mass starless clumps (HMSCs, of several hundred to a few thousand solar masses with a typical size of 0.1-1 pc), such as dust temperature and turbulence, on the clump scale. The question of whether the presence of H II regions modifies the core-scale (~0.025 pc) fra…