Search Publications
Permittivity of porous granular matter, in relation with Rosetta cometary mission
Brouet, Y.; Encrenaz, P.; Levasseur-Regourd, A. C. +1 more
We report measurements in laboratory conditions of the relative complex permittivity (hereafter permittivity) of porous material on a large range of frequencies from 50 MHz to 190 GHz. Such measurements, developed in preparation of the Rosetta mission to comet 67P/Churyumov-Gerasimenko, specifically for the MIRO radiometric experiment, were obtain…
Multiple asteroid systems (45) Eugenia and (87) Sylvia: Sensitivity to external and internal perturbations
Marchis, F.; Beauvalet, L.
Satellites of asteroids are a widely used way to determine the masses and other dynamical parameters of their systems. We make such a determination here, using data from the two triple-asteroid systems, (45) Eugenia and (87) Sylvia, that come from the Hubble Space Telescope and adaptive optics on three 8-10 m class telescopes (Keck, VLT, Gemini No…
Kinematic analysis of a sample of X-ray luminous distant galaxy clusters. The LX - σv relation in the z > 0.6 universe
Böhringer, H.; Pratt, G. W.; Rosati, P. +11 more
Aims: Observations and cosmological simulations show galaxy clusters as a family of nearly self-similar objects with properties that can be described by scaling relations as a function of mass and time. Here we study the scaling relations between the galaxy velocity dispersion (σv) and X-ray quantities, such as X-ray bolometric lum…
Discovery of new low-excitation planetary nebulae
Zhang, Yong; Hsia, Chih-Hao
We report a multi-wavelength study of four new planetary nebula (PN) candidates selected from the INT/WFC Photometric Hα Survey of the Northern Galactic Plane (IPHAS) and Deep Sky Hunter (DSH) catalogues. We present mid-resolution optical spectra of these PNs. The PN status of our sample was confirmed by optical narrow-band images and mid-resoluti…
Interaction Between Two CMEs During 14 - 15 February 2011 and Their Unusual Radio Signature
Shanmugaraju, A.; Prasanna Subramanian, S.; Ibrahim, M. Syed +1 more
We report a detailed analysis of an interaction between two coronal mass ejections (CMEs) that were observed on 14 - 15 February 2011 and the corresponding radio enhancement, which was similar to the "CME cannibalism" reported by Gopalswamy et al. (Astrophys. J.548, L91, 2001). A primary CME, with a mean field-of-view velocity of 669 km s−1
Magnetic pattern at supergranulation scale: the void size distribution
Berrilli, F.; Del Moro, D.; Scardigli, S.
The large-scale magnetic pattern observed in the photosphere of the quiet Sun is dominated by the magnetic network. This network, created by photospheric magnetic fields swept into convective downflows, delineates the boundaries of large-scale cells of overturning plasma and exhibits "voids" in magnetic organization. These voids include internetwo…
A thin diffuse component of the Galactic ridge X-ray emission and heating of the interstellar medium contributed by the radiation of Galactic X-ray binaries
Molaro, Margherita; Khatri, Rishi; Sunyaev, Rashid A.
We predict a thin diffuse component of the Galactic ridge X-ray emission (GRXE) arising from the scattering of the radiation of bright X-ray binaries (XBs) by the interstellar medium. This scattered component has the same scale height as that of the gaseous disk (~80 pc) and is therefore thinner than the GRXE of stellar origin (scale height ~130 p…
Entropy Flattening, Gas Clumping, and Turbulence in Galaxy Clusters
Lapi, A.; Fusco-Femiano, R.
Several physical processes and formation events are expected in cluster outskirts, a vast region up to now essentially not covered by observations. The recent Suzaku (X-ray) and Planck (Sunyaev-Zel'dovich (SZ) effect) observations out to the virial radius have highlighted in these peripheral regions a rather sharp decline of the intracluster gas t…
Higher prevalence of X-ray selected AGN in intermediate-age galaxies up to z ∼ 1
Barro, Guillermo; Pérez-González, Pablo G.; Nandra, Kirpal +9 more
We analyse the stellar populations in the host galaxies of 53 X-ray selected optically dull active galactic nuclei (AGN) at 0.34 < z < 1.07 with ultradeep (mAB = 26.5, 3σ) optical medium-band (R ∼ 50) photometry from the Survey for High-z Absorption Red and Dead Sources (SHARDS). The spectral resolution of SHARDS allows us to cons…
HST and LAMOST discover a dual active galactic nucleus in J0038+4128
Huang, Y.; Xiang, M. -S.; Yuan, H. -B. +6 more
We report the discovery of a kiloparsec-scale dual active galactic nucleus (AGN) in J0038+4128. From the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) images, we find two optical nuclei with a projection separation of 4.7 kpc (3.44 arcsec). The southern component (J0038+4128S) is spectroscopically observed with the HST Goddard…