Search Publications
Recurrent low-level luminosity behaviour after a giant outburst in the Be/X-ray transient 4U 0115+63
Degenaar, N.; Wijnands, R.; van den Eijnden, J. +4 more
In 2017, the Be/X-ray transient 4U 0115+63 exhibited a new type II outburst that was two times fainter than its 2015 giant outburst (in the Swift/BAT count rates). Despite this difference between the two bright events, the source displayed similar X-ray behaviour after these periods. Once the outbursts ceased, the source did not transit towards qu…
Spectroscopic observations of the machine-learning selected anomaly catalogue from the AllWISE Sky Survey
Gromadzki, M.; Thomas, R.; Sani, E. +7 more
We present the results of a programme to search and identify the nature of unusual sources within the All-sky Wide-field Infrared Survey Explorer (WISE) that is based on a machine-learning algorithm for anomaly detection, namely one-class support vector machines (OCSVM). Designed to detect sources deviating from a training set composed of known cl…
A Lyα nebula at z ∼ 3.3
Thomas, R.; Hibon, P.; Tang, F.
Context. Searching for high-redshift galaxies is a field of intense activity in modern observational cosmology that will continue to grow with future ground-based and sky observatories. Over the last few years, a lot has been learned about the high-z Universe.
Aims: Despite extensive Lyα blobs (LAB) surveys from low to high redshifts, giant L…
Dust and gas absorption in the high mass X-ray binary IGR J16318-4848
Fürst, Felix; Grinberg, Victoria; Kretschmar, Peter +11 more
Context. With an absorption column density on the order of 1024 cm-2, IGR J16318-4848 is one of the most extreme cases of a highly obscured high mass X-ray binary. In addition to the overall continuum absorption, the source spectrum exhibits a strong iron and nickel fluorescence line complex at 6.4 keV. Previous empirical mod…
Validating post-AGB candidates in the LMC and SMC using SALT spectra
Szczerba, R.; Gezer, I.; Hrivnak, B. J. +8 more
We selected a sample of post-AGB candidates in the Magellanic Clouds on the basis of their near- and mid-infrared colour characteristics. Fifteen of the most optically bright post-AGB candidates were observed with the South African Large Telescope in order to determine their stellar parameters and thus to validate or discriminate their nature as p…
Characterising young visual M-dwarf binaries with near-infrared integral field spectra
Calissendorff, Per; Janson, Markus; Bonnefoy, Mickaël
We present the results from an integral field spectroscopy study of seven close visual binary pairs of young M-dwarf multiple systems. The target systems are part of the astrometric monitoring AstraLux programme, surveying hundreds of M-dwarf systems for multiplicity and obtaining astrometric epochs for orbital constraints. Our new VLT/SINFONI dat…
Transiting exoplanets from the CoRoT space mission. XXIX. The hot Jupiters CoRoT-30 b and CoRoT-31 b
Mazeh, T.; Aigrain, S.; Alonso, R. +31 more
Aims: We report the discovery as well as the orbital and physical characterizations of two new transiting giant exoplanets, CoRoT-30 b and CoRoT-31 b, with the CoRoT space telescope.
Methods: We analyzed two complementary data sets: photometric transit light curves measured by CoRoT, and radial velocity curves measured by the HARPS spect…
An empirical metallicity tracer in CEMP and C-normal stars
Hansen, C. J.; Reichert, M.; Singh, D. +2 more
Context. Deriving the metallicity, [Fe/H], in low-resolution spectra of carbon-enhanced metal-poor (CEMP) stars is a tedious task that, owing to the large number of line blends, often leads to uncertainties on [Fe/H] exceeding 0.25 dex. The CEMP stars increase in number with decreasing [Fe/H] and some of these are known to be bona fide second gene…
ALMA and NACO observations towards the young exoring transit system J1407 (V1400 Cen)
Hales, A.; van der Marel, N.; Min, M. +8 more
Aims: Our aim was to directly detect the thermal emission of the putative exoring system responsible for the complex deep transits observed in the light curve for the young Sco-Cen star 1SWASP J140747.93-394542.6 (V1400 Cen, hereafter J1407), confirming it as the occulter seen in May 2007, and to determine its orbital parameters with respect …
Organic matter in interstellar dust lost at the approach to the heliosphere. Exothermic chemical reactions of free radicals ignited by the Sun
Kimura, Hiroshi; Postberg, Frank; Altobelli, Nicolas +1 more
Aims: We tackle the conundrums of organic materials missing from interstellar dust when measured inside the Solar System, while undoubtedly existing in the local interstellar cloud (LIC), which surrounds the Solar System.
Methods: We present a theoretical argument that organic compounds sublimate almost instantaneously by exothermic reac…