Search Publications
Red giants in the outer halo of the elliptical galaxy NGC 5128/Centaurus A
Bird, Sarah A.; Harris, William E.; Flynn, Chris +1 more
We used VIMOS on VLT to perform V and I band imaging of the outermost halo of
Influence of Planck foreground masks in the large angular scale quadrant CMB asymmetry
Cabella, P.; Santos, L.; Villela, T. +1 more
Context. The measured cosmic microwave background (CMB) angular distribution shows high consistency with the ΛCDM model, which predicts cosmological isotropy as one of its fundamental characteristics. However, isotropy violations were reported in CMB temperature maps of the Wilkinson Microwave Anisotropy Probe (WMAP) and confirmed by Planck satell…
A study of the past dynamics of comet 67P/Churyumov-Gerasimenko with fast Lyapunov indicators
Guzzo, Massimiliano; Lega, Elena
Comet 67P/Churyumov-Gerasimenko is the target of the Rosetta mission. On the basis of backward numerical integrations of a large set of simulated comets whose initial conditions were obtained from small variations of the orbital parameters of comet 67P, and using the analysis of suitable chaos indicators, we detect the phase-space structure of the…
Rotation period distribution of CoRoT and Kepler Sun-like stars
Pasquini, L.; Baglin, A.; Janot-Pacheco, E. +9 more
Aims: We study the distribution of the photometric rotation period (Prot), which is a direct measurement of the surface rotation at active latitudes, for three subsamples of Sun-like stars: one from CoRoT data and two from Kepler data. For this purpose, we identify the main populations of these samples and interpret their main bias…
Far-UV phase dependence and surface characteristics of comet 67P/Churyumov-Gerasimenko as observed with Rosetta Alice
Stern, S. A.; Feldman, P. D.; Bertaux, J. -L. +7 more
Aims. The Alice far-ultraviolet (FUV) spectrograph onboard Rosetta has, for the first time, imaged the surface of a comet, 67P/Churyumov-Gerasimenko (67P), in the FUV. With spatially resolved data, the nucleus properties are characterized in the FUV, including phase dependence, albedo, and spectral slope. Regional measurements across the nucleus a…
Constraining the intracluster pressure profile from the thermal SZ power spectrum
Bertoldi, F.; Pacaud, F.; Ramos-Ceja, M. E. +1 more
The angular power spectrum of the thermal Sunyaev-Zel'dovich (tSZ) effect is highly sensitive to cosmological parameters such as σ8 and Ωm, but its use as a precision cosmological probe is hindered by the astrophysical uncertainties in modeling the gas pressure profile in galaxy groups and clusters. In this paper we assume th…
X-ray galaxy clusters abundance and mass temperature scaling
Blanchard, Alain; Douspis, Marian; Ilić, Stéphane
The abundance of clusters of galaxies is known to be a potential source of cosmological constraints through their mass function. In the present work, we examine the information that can be obtained from the temperature distribution function of X-ray clusters. For this purpose, the mass-temperature (M - T) relation and its statistical properties ar…
Determining energy balance in the flaring chromosphere from oxygen V line ratios
Fletcher, L.; Labrosse, N.; Graham, D. R.
Context. The impulsive phase of solar flares is a time of rapid energy deposition and heating in the lower solar atmosphere, leading to changes in the temperature and density structure of the region.
Aims: We use an O v density diagnostic formed from the λ192 /λ248 line ratio, provided by the Hinode/EIS instrument, to determine the density of…
The physical state of selected cold clumps
Juvela, M.; Parikka, A.; Malinen, J. +2 more
Context. The study of prestellar cores is essential to understanding the initial stages of star formation. With Herschel more cold clumps have been detected than ever before. For this study we have selected 21 cold clumps from 20 Herschel fields observed as a follow-up on original Planck detections. We have observed these clumps in 13CO…
Constraints on the gas content of the Fomalhaut debris belt. Can gas-dust interactions explain the belt's morphology?
Olofsson, G.; Dent, W. R. F.; Kamp, I. +5 more
Context. The 440 Myr old main-sequence A-star Fomalhaut is surrounded by an eccentric debris belt with sharp edges. This sort of a morphology is usually attributed to planetary perturbations, but the orbit of the only planetary candidate detected so far, Fomalhaut b, is too eccentric to efficiently shape the belt. Alternative models that could acc…