Search Publications
Planck early results. XVIII. The power spectrum of cosmic infrared background anisotropies
Kneissl, R.; Miville-Deschênes, M. -A.; Bernard, J. -P. +202 more
Using Planck maps of six regions of low Galactic dust emission with a total area of about 140 deg2, we determine the angular power spectra of cosmic infrared background (CIB) anisotropies from multipole ℓ = 200 to ℓ = 2000 at 217, 353, 545 and 857 GHz. We use 21-cm observations of Hi as a tracer of thermal dust emission to reduce the al…
Planck early results. XXV. Thermal dust in nearby molecular clouds
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +197 more
Planck allows unbiased mapping of Galactic sub-millimetre and millimetre emission from the most diffuse regions to the densest parts of molecular clouds. We present an early analysis of the Taurus molecular complex, on line-of-sight-averaged data and without component separation. The emission spectrum measured by Planck and IRAS can be fitted pixe…
Planck early results. XI. Calibration of the local galaxy cluster Sunyaev-Zeldovich scaling relations
Kneissl, R.; Dahle, H.; Miville-Deschênes, M. -A. +207 more
We present precise Sunyaev-Zeldovich (SZ) effect measurements in the direction of 62 nearby galaxy clusters (z < 0.5) detected at high signal-to-noise in the first Planck all-sky data set. The sample spans approximately a decade in total mass, 2 × 1014 M⊙ < M500 < 2 × 1015 M⊙, where M…
The cool-core bias in X-ray galaxy cluster samples. I. Method and application to HIFLUGCS
Paltani, S.; Molendi, S.; Eckert, D.
Aims: When selecting flux-limited cluster samples, the detection efficiency of X-ray instruments is not the same for centrally-peaked and flat objects, which introduces a bias in flux-limited cluster samples. We quantify this effect in the case of a well-known cluster sample, HIFLUGCS.
Methods: We simulate a population of X-ray clusters …
A mature cluster with X-ray emission at z = 2.07
Finoguenov, A.; Cimatti, A.; Daddi, E. +10 more
We report evidence of a fully established galaxy cluster at z = 2.07, consisting of a ~20σ overdensity of red, compact spheroidal galaxies spatially coinciding with extended X-ray emission detected with XMM-Newton. We use VLT VIMOS and FORS2 spectra and deep Subaru, VLT and Spitzer imaging to estimate the redshift of the structure from a prominent…
Planck early results. XXIV. Dust in the diffuse interstellar medium and the Galactic halo
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +205 more
This paper presents the first results from a comparison of Planck dust maps at 353, 545 and 857GHz, along with IRAS data at 3000 (100 µm) and 5000GHz (60 µm), with Green Bank Telescope 21-cm observations of Hi in 14 fields covering more than 800 deg2 at high Galactic latitude. The main goal of this study is to estimate the f…
Non-standard grain properties, dark gas reservoir, and extended submillimeter excess, probed by Herschel in the Large Magellanic Cloud
Bernard, J. -P.; Reach, W. T.; Lebouteiller, V. +13 more
Context.Herschel provides crucial constraints on the IR SEDs of galaxies, allowing unprecedented accuracy on the dust mass estimates. However, these estimates rely on non-linear models and poorly-known optical properties.
Aims: In this paper, we perform detailed modelling of the Spitzer and Herschel observations of the LMC, in order to: (i) s…
Photospheric flux cancellation and associated flux rope formation and eruption
Green, L. M.; Kliem, B.; Wallace, A. J.
Aims: We study an evolving bipolar active region that exhibits flux cancellation at the internal polarity inversion line, the formation of a soft X-ray sigmoid along the inversion line and a coronal mass ejection. The aim is to investigate the quantity of flux cancellation that is involved in flux rope formation in the time period leading up …
Planck early results. XX. New light on anomalous microwave emission from spinning dust grains
Kneissl, R.; Miville-Deschênes, M. -A.; Boulanger, F. +213 more
Anomalous microwave emission (AME) has been observed by numerous experiments in the frequency range ~10-60 GHz. Using Planck maps and multi-frequency ancillary data, we have constructed spectra for two known AME regions: the Perseus and ρ Ophiuchi molecular clouds. The spectra are well fitted by a combination of free-free radiation, cosmic microwa…
Search for brown-dwarf companions of stars
Zucker, S.; Queloz, D.; Sahlmann, J. +7 more
Context. The frequency of brown-dwarf companions in close orbit around Sun-like stars is low compared to the frequency of planetary and stellar companions. There is presently no comprehensive explanation of this lack of brown-dwarf companions.
Aims: By combining the orbital solutions obtained from stellar radial-velocity curves and Hipparcos …