Search Publications
Faint recombination lines in Galactic PNe with a [WC] nucleus
García-Rojas, J.; Peña, M.; Peimbert, A.
Aims: We present spatially resolved high-resolution spectrophotometric data for the planetary nebulae PB 8, NGC 2867, and PB 6. We have analyzed two knots in NGC 2867 and PB 6 and one in PB 8. The three nebulae are ionized by [WC] type nuclei: early [WO] for PB 6 and NGC 2867 and [WC 5-6] in the case of PB 8. Our aim is to study the behavior of th…
Quasar induced galaxy formation: a new paradigm?
Elbaz, D.; Jahnke, K.; Pantin, E. +2 more
Aims: We discuss observational evidence that quasars play a key role in the formation of galaxies, starting from the detailed study of the quasar HE0450-2958 and extending the discussion to a series of converging evidence that radio jets may trigger galaxy formation.
Methods: We use mid infrared imaging with VISIR at the ESO-VLT to model the m…
Modelling shock drift acceleration of electrons at the reconnection outflow termination shock in solar flares. Observational constraints and parametric study
Mann, G.; Aurass, H.; Warmuth, A.
Context: The acceleration of electrons to nonthermal energies in solar flares is one of the main unsolved questions in solar physics. One possibility for producing these energetic electrons is acceleration at the reconnection outflow termination shock (TS).
Aims: By comparing theoretical results with observations of nonthermal electrons, we de…
The chemical composition of carbon stars. The R-type stars
Abia, C.; Cristallo, S.; Plez, B. +2 more
Aims. The aim of this work is to shed some light on the problem of the formation of carbon stars of R-type from a detailed study of their chemical composition.
Methods: We use high-resolution and high signal-to-noise optical spectra of 23 R-type stars (both early- and late-types) selected from the Hipparcos catalogue. The chemical analysis is …
MCAO near-IR photometry of the globular cluster NGC 6388: MAD observations in crowded fields
Moretti, A.; Falomo, R.; Anderson, J. +15 more
Context: Deep photometry of crowded fields, such as Galactic globular clusters, is severely limited by the resolution of ground-based telescopes. On the other hand, the Hubble Space Telescope does not have the near-infrared (NIR) filters needed to allow large color baselines.
Aims: In this work we demonstrate how ground based observations can …
Propagating transverse waves in soft X-ray coronal jets
Nakariakov, V. M.; Verwichte, E.; Van Doorsselaere, T. +1 more
Aims: The theoretical model for magnetohydrodynamic (MHD) modes guided by a field-aligned plasma cylinder with a steady flow is adapted to interpret transverse waves observed in solar coronal hot jets, discovered with Hinode/XRT in terms of fast magnetoacoustic kink modes.
Methods: Dispersion relations for linear magnetoacoustic perturbations …
Multi-frequency imaging of the galaxy cluster Abell 2163 using the Sunyaev-Zel'dovich effect
Kneissl, R.; Menten, K. M.; Ade, P. A. R. +30 more
Context: Observations of the Sunyaev-Zel'dovich effect (SZE) from galaxy clusters are emerging as a powerful tool in cosmology. Besides large cluster surveys, resolved SZE images of individual clusters can shed light on the physics of the intra-cluster medium (ICM) and allow accurate measurements of the cluster gas and total masses.
Aims: We u…
Properties of M31 . I. Dust. Basic properties and a discussion about age-dependent dust heating
Montalto, M.; Seitz, S.; Lee, C. -H. +3 more
Aims: Observations acquired by the Spitzer Space Telescope and improvements to theoretical modeling of dust emission properties are used to discuss the distribution of dust and its characteristics in the closest neighbor spiral galaxy
Morphology and density structure of post-CME current sheets
Webb, D. F.; Raymond, J. C.; Vršnak, B. +11 more
Context: Eruption of a coronal mass ejection (CME) drags and “opens” the coronal magnetic field, presumably leading to the formation of a large-scale current sheet and field relaxation by magnetic reconnection.
Aims: We analyze the physical characteristics of ray-like coronal features formed in the aftermath of CMEs, to confirm whether interpr…
Frequency and properties of bars in cluster and field galaxies at intermediate redshifts
Jogee, S.; Pelló, R.; White, S. D. M. +15 more
We present a study of large-scale bars in field and cluster environments out to redshifts of ~0.8 using a final sample of 945 moderately inclined disk galaxies drawn from the EDisCS project. We characterize bars and their host galaxies and look for relations between the presence of a bar and the properties of the underlying disk. We investigate wh…