Search Publications
XZ: Deriving redshifts from X-ray spectra of obscured AGN
Bauer, F. E.; Salvato, M.; Buchner, J. +2 more
Context. Redshifts are fundamental for our understanding of extragalactic X-ray sources. Ambiguous counterpart associations, expensive optical spectroscopy, and/or multimission multiwavelength coverage to resolve degeneracies often make estimation difficult in practice.
Aims: We attempt to constrain redshifts of obscured active galactic nucle…
Astrometry and exoplanets in the Gaia era: a Bayesian approach to detection and parameter recovery
Ranalli, P.; Lindegren, L.; Hobbs, D.
The Gaia mission is expected to make a significant contribution to the knowledge of exoplanet systems, both in terms of their number and of their physical properties. We develop Bayesian methods and detection criteria for orbital fitting, and revise the detectability of exoplanets in light of the in-flight properties of Gaia. Limiting ourselves to…
Non-damping oscillations at flaring loops
Li, D.; Zhang, Q. M.; Ning, Z. J. +3 more
Context. Quasi-periodic oscillations are usually detected as spatial displacements of coronal loops in imaging observations or as periodic shifts of line properties (i.e., Doppler velocity, line width and intensity) in spectroscopic observations. They are often applied for remote diagnostics of magnetic fields and plasma properties on the Sun.
Searching for the weakest detectable magnetic fields in white dwarfs. Highly-sensitive measurements from first VLT and WHT surveys
Bagnulo, S.; Landstreet, J. D.
Our knowledge of the magnetism in white dwarfs is based on an observational dataset that is biased in favour of stars with very strong magnetic fields. Most of the field measurements available in the literature have a relatively low sensitivity, while current instruments allow us to detect magnetic fields of white dwarfs with sub-kG precision. Wit…
ALMA observations of AGN fuelling. The case of PKS B1718-649
Morganti, R.; Emonts, B. H. C.; Oonk, J. B. R. +2 more
We present ALMA observations of the 12CO (2-1) line of the newly born (tradio 102 years) active galactic nucleus (AGN), PKS B1718-649. These observations reveal that the carbon monoxide in the innermost 15 kpc of the galaxy is distributed in a complex warped disk. In the outer parts of this disk, the CO gas follows…
The 500 ks Chandra observation of the z = 6.31 QSO SDSS J1030 + 0524
Prandoni, I.; Cappi, M.; Vignali, C. +23 more
We present the results from a 500 ks Chandra observation of the z = 6.31 QSO SDSS J1030 + 0524. This is the deepest X-ray observation to date of a z 6 QSO. The QSO is detected with a total of 125 net counts in the full (0.500A0-7 keV) band and its spectrum can be modeled by a single power-law model with photon index of Γ = 1.81 ± 0.18 and full ban…
The double population of Chamaeleon I detected by Gaia DR2
Franciosini, E.; Randich, S.; Roccatagliata, V. +1 more
Context. Chamaeleon I represents an ideal laboratory to study the cluster formation in a low-mass environment. Recently, two sub-clusters spatially located in the northern and southern parts of Chamaeleon I were found with different ages and radial velocities.
Aims: In this Letter we report new insights into the structural properties, age, an…
Planetary nebula distances in Gaia DR2
Kimeswenger, S.; Barría, D.
Context. Planetary nebula distance scales often suffer from model-dependent solutions. Model-independent trigonometric parallaxes have been rare. Space-based trigonometric parallaxes are now available for a larger sample using the second Data Release of Gaia.
Aims: We aim to derive a high-quality approach for selection criteria of trigonometr…
VLTI/MIDI atlas of disks around low- and intermediate-mass young stellar objects
Matter, A.; Jaffe, W.; Ábrahám, P. +13 more
Context. Protoplanetary disks show large diversity regarding their morphology and dust composition. With mid-infrared interferometry the thermal emission of disks can be spatially resolved, and the distribution and properties of the dust within can be studied.
Aims: Our aim is to perform a statistical analysis on a large sample of 82 disks ar…
Gaia Data Release 2. Rotational modulation in late-type dwarfs
Audard, M.; Pagano, I.; Rimoldini, L. +12 more
Context. Amongst the ≈5 × 105 sources identified as variable stars in Gaia Data Release 2 (DR2), 26% are rotational modulation variable candidates of the BY Dra class. Gaia DR2 provides their multi-band (G, GBP, and GRP) photometric time series collected by the European Space Agency spacecraft Gaia during the first…