Search Publications
Consistent accretion-induced heating of the neutron-star crust in MXB 1659-29 during two different outbursts
Degenaar, N.; Wijnands, R.; Homan, J. +10 more
Monitoring the cooling of neutron-star crusts heated during accretion outbursts allows us to infer the physics of the dense matter present in the crust. We examine the crust cooling evolution of the low-mass X-ray binary MXB 1659-29 up to ∼505 days after the end of its 2015 outburst (hereafter outburst II) and compare it with what we observed afte…
Radial abundance gradients in the outer Galactic disk as traced by main-sequence OB stars
McMillan, P. J.; Oey, M. S.; Borges Fernandes, M. +8 more
Context. Elemental abundance gradients in galactic disks are important constraints for models of how spiral galaxies form and evolve. However, the abundance structure of the outer disk region of the Milky Way is poorly known, which hampers our understanding of the spiral galaxy that is closest to us and that can be studied in greatest detail. Youn…
Background modelling for γ-ray spectroscopy with INTEGRAL/SPI
Diehl, Roland; Greiner, Jochen; Siegert, Thomas +3 more
Context. The coded-mask spectrometer-telescope SPI on board the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL) records photons in the energy range between 20 and 8000 keV. A robust and versatile method for modelling the dominating instrumental background radiation is difficult to establish for such a telescope in the rapidly changing s…
Hot UV-bright stars of galactic globular clusters
Lanz, T.; Miller Bertolami, M. M.; Landsman, W. B. +1 more
Context. We have performed a census of the UV-bright population in 78 globular clusters using wide-field UV telescopes. This population includes a variety of phases of post-horizontal branch (HB) evolution, including hot post-asymptotic giant branch (AGB) stars, and post-early AGB stars. There are indications that old stellar systems like globular…
ALMA observations of PKS 1549-79: a case of feeding and feedback in a young radio quasar
Morganti, Raffaella; Oosterloo, Tom; Tadhunter, Clive +4 more
We present CO(1-0) and CO(3-2) Atacama Large Millimeter/submillimeter Array observations of the molecular gas in PKS 1549-79, as well as mm and very long baseline interferometry 2.3-GHz continuum observations of its radio jet. PKS 1549-79 is one of the closest young, radio-loud quasars caught in an on-going merger in which the active galactic nucl…
Heavy metals in intermediate He-rich hot subdwarfs: the chemical composition of HZ 44 and HD 127493
Heber, U.; Latour, M.; Dorsch, M.
Context. Hot subluminous stars can be spectroscopically classified as subdwarf B (sdB) and O (sdO) stars. While the latter are predominantly hydrogen deficient, the former are mostly helium deficient. The atmospheres of most sdOs are almost devoid of hydrogen, whereas a small group of hot subdwarf stars of mixed H/He composition exists, showing ex…
The XMM-Newton serendipitous survey. VIII. The first XMM-Newton serendipitous source catalogue from overlapping observations
Motch, C.; Page, M. J.; Carrera, F. +13 more
Context. XMM-Newton has observed the X-ray sky since early 2000. The XMM-Newton Survey Science Centre Consortium has published catalogues of X-ray and ultraviolet sources found serendipitously in the individual observations. This series is now augmented by a catalogue dedicated to X-ray sources detected in spatially overlapping XMM-Newton observat…
A progenitor candidate for the type II-P supernova SN 2018aoq in NGC 4151
Gromadzki, M.; Smartt, S. J.; Kotak, R. +9 more
We present our findings based on pre- and post-explosion data of the type II-Plateau SN 2018aoq that exploded in NGC 4151. As distance estimates to NGC 4151 vary by an order of magnitude, we utilised the well-known correlation between ejecta velocity and plateau brightness, i.e. the standard candle method, to obtain a distance of 18.2 ± 1.2 Mpc, w…
Merger induced clump formation in distant infrared luminous starburst galaxies
Calabrò, Antonello; Daddi, Emanuele; Jin, Shuowen +6 more
While the formation of stellar clumps in distant galaxies is usually attributed to gravitational violent disk instabilities, we show here that major mergers also represent a competitive mechanism to form bright clumps. Using ∼0.1″ resolution ACS F814W images in the entire COSMOS field, we measured the fraction of clumpy emission in 109 main sequen…
Galactocentric acceleration in VLBI analysis. Findings of IVS WG8
Gipson, J. M.; Gordon, D.; MacMillan, D. S. +8 more
Aims: The IVS Working Group on Galactic Aberration (WG8) was established to investigate issues related to incorporating the effect of Galactic aberration in IVS analysis. The circular motion of the solar system barycenter around the Galactic center causes a change in aberration, which in the case of geodetic VLBI observing is over time scales…