Search Publications
Super Heavy Dark Matter in light of BICEP2, Planck and Ultra High Energy Cosmic Rays Observations
Matarrese, S.; Aloisio, R.; Olinto, A. V.
The announcement by BICEP2 of the detection of B-mode polarization consistent with primordial gravitational waves with a tensor-to-scalar ratio, r=0.2+0.07-0.05, challenged predictions from most inflationary models of a lower value for r. More recent results by Planck on polarized dust emission show that the observed tensor m…
Discovery of a Strongly Lensed Massive Quiescent Galaxy at z = 2.636: Spatially Resolved Spectroscopy and Indications of Rotation
Ellis, Richard S.; Belli, Sirio; Newman, Andrew B.
We report the discovery of RG1M0150, a massive, recently quenched galaxy at z = 2.636 that is multiply imaged by the cluster MACSJ0150.3-1005. We derive a stellar mass of {log}{M}*={11.49}-0.16+0.10 and a half-light radius of {R}e,{maj}=1.8+/- 0.4 {{kpc}}. Taking advantage of the lensing magnification, w…
Correlation between Galaxy Mergers and Luminous Active Galactic Nuclei
Ho, Luis C.; Im, Myungshin; Kim, Minjin +1 more
It is not yet clear what triggers the activity of active galactic nuclei (AGNs), but galaxy merging has been suspected to be one of the main mechanisms fueling the activity. Using deep optical images taken at various ground-based telescopes, we investigate the fraction of galaxy mergers in 39 luminous AGNs (MR ≲ -22.6 mag) at z ≤ 0.3 (a…
X-Ray and EUV Observations of Simultaneous Short and Long Period Oscillations in Hot Coronal Arcade Loops
Kumar, Pankaj; Cho, Kyung-Suk; Nakariakov, Valery M.
We report decaying quasi-periodic intensity oscillations in the X-ray (6-12 keV) and extreme-ultraviolet (EUV) channels (131, 94, 1600, 304 Å) observed by the Fermi Gamma-ray Burst Monitor and Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA), respectively, during a C-class flare. The estimated periods of oscillation and decay time in …
Radiative braking in the extended exosphere of GJ 436 b
Ehrenreich, D.; Lecavelier des Etangs, A.; Bourrier, V.
The recent detection of a giant exosphere surrounding the warm Neptune GJ 436 b has shed new light on the evaporation of close-in planets, revealing that moderately irradiated, low-mass exoplanets could make exceptional targets for studying this mechanism and its impact on the exoplanet population. Three HST/STIS observations were performed in the…
Magnetic Structure and Dynamics of the Erupting Solar Polar Crown Prominence on 2012 March 12
Reeves, Katharine K.; van Ballegooijen, Adriaan; DeLuca, Edward E. +3 more
We present an investigation of the polar crown prominence that erupted on 2012 March 12. This prominence is observed at the southeast limb by the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA; end-on view) and displays a quasi-vertical thread structure. A bright U-shaped or horn-like structure is observed surrounding the upper…
NuSTAR Reveals Extreme Absorption in z < 0.5 Type 2 Quasars
Harrison, F. A.; Stern, D.; Zhang, W. W. +27 more
The intrinsic column density (NH) distribution of quasars is poorly known. At the high obscuration end of the quasar population and for redshifts z < 1, the X-ray spectra can only be reliably characterized using broad-band measurements that extend to energies above 10 keV. Using the hard X-ray observatory NuSTAR, along with archival …
Mixed aliphatic and aromatic composition of evaporating very small grains in NGC 7023 revealed by the 3.4/3.3 µm ratio
Boulanger, F.; Joblin, C.; Onaka, T. +1 more
Context. A chemical scenario was proposed for photon-dominated regions (PDRs) according to which UV photons from nearby stars lead to the evaporation of very small grains (VSGs) and the production of gas-phase polycyclic aromatic hydrocarbons (PAHs).
Aims: Our goal is to achieve better insight into the composition and evolution of evaporating…
XMM-Newton Survey of Local O VII Absorption Lines in the Spectra of Active Galactic Nuclei
Fang, Taotao; Bullock, James; Buote, David +1 more
Highly ionized, z = 0 metal absorption lines detected in the X-ray spectra of background active galactic nuclei (AGNs) provide an effective method to probe the hot (T ∼ 106 K) gas and its metal content in and around the Milky Way. We present an all-sky survey of the {{K}α } transition of the local O vii absorption lines obtai…
Scientific assessment of the quality of OSIRIS images
Jorda, L.; Lamy, P. L.; Bertaux, J. -L. +51 more
Context. OSIRIS, the scientific imaging system onboard the ESA Rosetta spacecraft, has been imaging the nucleus of comet 67P/Churyumov-Gerasimenko and its dust and gas environment since March 2014. The images serve different scientific goals, from morphology and composition studies of the nucleus surface, to the motion and trajectories of dust gra…