Search Publications
A comprehensive study of NGC 2345, a young open cluster with a low metallicity
Castro, N.; Negueruela, I.; Tabernero, H. M. +3 more
Context. NGC 2345 is a young open cluster that hosts seven blue and red supergiants, low metallicity, and a high fraction of Be stars, which makes it a privileged laboratory to study stellar evolution.
Aims: We aim to improve the determination of the cluster parameters and study the Be phenomenon. Our objective is also to characterise the sev…
Local Bubble contribution to the 353-GHz dust polarized emission
Pelgrims, V.; Skalidis, R.
It has not been shown so far whether the diffuse Galactic polarized emission at frequencies relevant for cosmic microwave background (CMB) studies originates from nearby or more distant regions of our Galaxy. This questions previous attempts that have been made to constrain magnetic field models at local and large scales. The scope of this work is…
The HST/ACS star formation history of the Tucana dwarf spheroidal galaxy: clues from the horizontal branch
Salaris, M.; Monelli, M.; Tolstoy, E. +2 more
We report a new star formation history for the Tucana dwarf spheroidal galaxy, obtained from a new look at a deep HST/ACS colour-magnitude diagram. We combined information from the main sequence turn-off and the horizontal branch to resolve the ancient star formation rates on a finer temporal scale than previously possible. We show that Tucana exp…
The CARMENES search for exoplanets around M dwarfs. The enigmatic planetary system GJ 4276: one eccentric planet or two planets in a 2:1 resonance?
Schmitt, J. H. M. M.; Nagel, E.; Amado, P. J. +25 more
We report the detection of a Neptune-mass exoplanet around the M4.0 dwarf GJ 4276 (G 232-070) based on radial velocity (RV) observations obtained with the CARMENES spectrograph. The RV variations of GJ 4276 are best explained by the presence of a planetary companion that has a minimum mass of mb sin i ≈ 16 M⊕ on a Pb
The EUV spectrum of the Sun: Quiet- and active-Sun irradiances and chemical composition
Del Zanna, G.
We benchmark new atomic data against a selection of irradiances obtained from medium-resolution quiet-Sun spectra in the extreme ultraviolet (EUV), from 60 to 1040 Å. We used as a baseline the irradiances measured during solar minimum on 2008 April 14 by the prototype (PEVE) of the Solar Dynamics Observatory Extreme ultraviolet Variability Experim…
HST/COS observations of the newly discovered obscuring outflow in NGC 3783
Kaastra, J. S.; Kriss, G. A.; Arav, N. +24 more
Aims: To understand the nature of transient obscuring outflows in active galactic nuclei, we use simultaneous multiwavelength observations with XMM-Newton, NuSTAR, the Hubble Space Telescope (HST), and the Max Planck Gesellschaft/European Southern Observatory (ESO) 2.2 m telescope triggered by soft X-ray absorption detected by Swift.
Met…
A deep XMM-Newton look on the thermally emitting isolated neutron star RX J1605.3+3249
Haberl, F.; Motch, C.; Zane, S. +3 more
Previous XMM-Newton observations of the thermally emitting isolated neutron star RX J1605.3+3249 provided a candidate for a shallow periodic signal and evidence of a fast spin down, which suggested a high dipolar magnetic field and an evolution from a magnetar. We obtained a large programme with XMM-Newton to confirm its candidate timing solution,…
Measuring the filamentary structure of interstellar clouds through wavelets
Ossenkopf-Okada, V.; Stepanov, R.
Context. The ubiquitous presence of filamentary structures in the interstellar medium asks for an unbiased characterization of their properties including a stability analysis.
Aims: We propose a novel technique to measure the spectrum of filaments in any two-dimensional data set. By comparing the power in isotropic and anisotropic structures …
Spectroscopic membership for the populous 300 Myr-old open cluster NGC 3532
Strassmeier, K. G.; Barnes, S. A.; James, D. J. +3 more
Context. NGC 3532 is an extremely rich open cluster embedded in the Galactic disc, hitherto lacking a comprehensive, documented membership list.
Aims: We provide membership probabilities from new radial velocity observations of solar-type and low-mass stars in NGC 3532, in part as a prelude to a subsequent study of stellar rotation in the clu…
Discovery of weak magnetic fields in four DZ white dwarfs in the local 20 pc volume. Implications for the frequency of magnetic fields with cooling age
Bagnulo, S.; Landstreet, J. D.
We report the discovery of weak magnetic fields in three white dwarfs within the local 20 pc volume (WD 0816-310, WD 1009-184, and WD 1532+129), and we confirm the magnetic nature of a fourth star (WD 2138-332) in which we had previously detected a field at a 3σ level. The spectra of all these white dwarfs are characterised by the presence of meta…