Search Publications
Conversion from mutual helicity to self-helicity observed with IRIS
Peter, H.; Zhang, J.; Li, L. P. +1 more
Context. In the upper atmosphere of the Sun observations show convincing evidence for crossing and twisted structures, which are interpreted as mutual helicity and self-helicity.
Aims: We use observations with the new Interface Region Imaging Spectrograph (IRIS) to show the conversion of mutual helicity into self-helicity in coronal structure…
Metal distribution in sloshing galaxy clusters: the case of A496
Molendi, Silvano; Ghizzardi, Simona; De Grandi, Sabrina
We report results from a detailed study of the sloshing gas in the core of A496. We detected the low-temperature/entropy spiral feature found in several cores. We also found that conduction between the gas in the spiral and the ambient medium must be suppressed by more than one order of magnitude compared with the Spitzer conductivity. Intriguingl…
Spectroscopy of BL Lacertae objects of extraordinary luminosity
Sbarufatti, B.; Falomo, R.; Treves, A. +1 more
Aims: We aim to determine the redshift (or stringent lower limits) of a number of bright BL Lacs objects.
Methods: We secured optical and near-infrared medium-resolution spectra of four bright BL Lac objects of unknown redshift using the spectrograph X-Shooter at the ESO-VLT.
Results: In spite of the high quality of the spectra and …
Modeling magnesium escape from HD 209458b atmosphere
Lecavelier des Etangs, A.; Bourrier, V.; Vidal-Madjar, A.
Transit observations in the Mg i line of HD 209458b revealed signatures of neutral magnesium escaping the upper atmosphere of the planet, while no atmospheric absorption was found in the Mg ii doublet. Here we present a 3D particle model of the dynamics of neutral and ionized magnesium populations, coupled with an analytical modeling of the atmosp…
The rapid evolution of the exciting star of the Stingray nebula
Rauch, T.; Werner, K.; Kruk, J. W. +5 more
Context.
Structure and substructure analysis of DAFT/FADA galaxy clusters in the [0.4-0.9] redshift range
Ilbert, O.; Schirmer, M.; Allam, S. +29 more
Context. The DAFT/FADA survey is based on the study of ~90 rich (masses found in the literature >2 × 1014 M⊙) and moderately distant clusters (redshifts 0.4 < z < 0.9), all with HST imaging data available. This survey has two main objectives: to constrain dark energy (DE) using weak lensing tomography on galaxy clust…
Warm molecular gas temperature distribution in six local infrared bright Seyfert galaxies
Spinoglio, Luigi; Pereira-Santaella, Miguel; van der Werf, Paul P. +1 more
We simultaneously analyze the spectral line energy distributions (SLEDs) of CO and H2 of six local luminous infrared (IR) Seyfert galaxies. For the CO SLEDs, we used new Herschel/SPIRE FTS data (from J = 4-3 to J = 13-12) and ground-based observations for the lower-J CO transitions. The H2 SLEDs were constructed using archiva…
To the center of cold spot with Planck
Gurzadyan, V. G.; Kashin, A. L.; Sargsyan, S. +3 more
The structure of the cold spot, of a non-Gaussian anomaly in the cosmic microwave background (CMB) sky detected earlier by Vielva et al. (2004, ApJ, 609, 22), is studied using the data by Planck satellite. The map obtained of the degree of stochasticity (K-map) of CMB for the cold spot, reveals, most clearly in 100 GHz band, a shell-type structure…
The Herschel Planetary Nebula Survey (HerPlaNS). I. Data overview and analysis demonstration with NGC 6781
Nordon, R.; Sahai, R.; Behar, E. +30 more
Context. This is the first of a series of investigations into far-IR characteristics of 11 planetary nebulae (PNe) under the Herschel Space Observatory open time 1 program, Herschel Planetary Nebula Survey (HerPlaNS).
Aims: Using the HerPlaNS data set, we look into the PN energetics and variations of the physical conditions within the target …
Radiation-pressure-driven dust waves inside bursting interstellar bubbles
Kaper, L.; Tielens, A. G. G. M.; Berné, O. +3 more
Massive stars drive the evolution of the interstellar medium through their radiative and mechanical energy input. After their birth, they form "bubbles" of hot gas surrounded by a dense shell. Traditionally, the formation of bubbles is explained through the input of a powerful stellar wind, even though direct evidence supporting this scenario is l…