Search Publications
Broadband spectrum of the total X-ray emission from the galaxy M31
Sunyaev, R. A.; Tsygankov, S. S.; Revnivtsev, M. G. +2 more
We present the results of measurements of the total X-ray flux from the Andromeda galaxy (M31) in the 3-100 keV band based on data from the RXTE/PCA, INTEGRAL/ISGRI, and SWIFT/BAT space experiments. We show that the total emission from the galaxy has a multicomponent spectrum whose main characteristics are specified by binaries emitting in the opt…
Temperature Anisotropy in the Presence of Ultra Low Frequency Waves in the Terrestrial Foreshock
Eastwood, J. P.; Burgess, D.; Nakariakov, V. M. +3 more
We report the first study of the correlation between elevated solar wind core plasma temperatures and temperature anisotropy in the terrestrial foreshock. Plasma temperature is enhanced near the fire hose marginal stability threshold in the presence of ultra low frequency (ULF) large amplitude magnetic perturbations, which are intrinsically right-…
Non-Gaussianities in DBI inflation with angular motion
Kidani, Taichi; Koyama, Kazuya
We study DBI spinflation models with angular potentials that are derived in string theory. We analyze the background dynamics with different parameter sets and study the impact of changing each parameter on inflationary dynamics. It is known that the conversion of the entropy perturbation into the curvature perturbation gives multifield Dirac-Born…
Updated constraints on large field hybrid inflation
Clesse, Sébastien; Rekier, Jérémy
We revisit the status of hybrid inflation in the light of Planck and recent BICEP2 results, taking care of possible transient violations of the slow-roll conditions as the field passes from the large field to the vacuum dominated phase. The usual regime where observable scales exit the Hubble radius in the vacuum dominated phase predicts a blue sc…
Discovery of a New Black Hole Transient within 100'' (400 pc) of M31*
Murray, S. S.; Garcia, M. R.; Barnard, R. +1 more
We identified a new X-ray transient CXOM31 004252.457+411631.17 (T13) in M31 during a 2013 June Chandra observation. This system is particularly exciting because it is located within 100'' of M31*; it is thought that this region of the bulge is sufficiently dense to form X-ray binaries dynamically, but only systems with black hole accretors and/or…
Multiwavelength Study of the Northeastern Outskirts of the Extended TeV Source HESS J1809-193
Pavlov, George G.; Kargaltsev, Oleg; Hare, Jeremy +3 more
HESS J1809-193 is an extended TeV γ-ray source in the Galactic plane. Multiwavelength observations of the HESS J1809-193 field reveal a complex picture. We present results from three Chandra X-Ray Observatory and two Suzaku observations of a region in the northeastern outskirts of HESS J1809-193, where enhanced TeV emission has been reported. Our …
An Ensemble Study of a January 2010 Coronal Mass Ejection (CME): Connecting a Non-obvious Solar Source with Its ICME/Magnetic Cloud
Webb, D. F.; Möstl, C.; Farrugia, C. J. +9 more
A distinct magnetic cloud (MC) was observed in-situ at the Solar TErrestrial RElations Observatory (STEREO)-B on 20 - 21 January 2010. About three days earlier, on 17 January, a bright flare and coronal mass ejection (CME) were clearly observed by STEREO-B, which suggests that this was the progenitor of the MC. However, the in-situ speed of the ev…
Planck constraints on neutrino isocurvature density perturbations
Di Valentino, Eleonora; Melchiorri, Alessandro
The recent cosmic microwave background data from the Planck satellite experiment, when combined with Hubble Space Telescope determinations of the Hubble constant, are compatible with a larger, nonstandard number of relativistic degrees of freedom at recombination, parametrized by the neutrino effective number Neff . In the curvaton scen…
Two-Way Frequency Fluctuations Observed During Coronal Radio Sounding Experiments
Pätzold, M.; Bird, M. K.; Efimov, A. I. +5 more
Coronal radio-sounding experiments were carried out using two-way coherent dual-frequency carrier signals of the ESA spacecraft Rosetta (ROS) in 2006. Frequency measurements recorded at both NASA and ESA tracking stations (sample rate: 1 Hz) are analyzed in this work. Spectral analysis of the S-band, X-band, and differential frequency records has …
Cosmic rays in the heliosphere: Observations
Moraal, Harm
This contribution to the 100th commemoration of the discovery of cosmic rays (6-8 August, 2012 in Bad Saarow, Germany) is about observations of those cosmic rays that are sensitive to the structure and the dynamics of the heliosphere. This places them in the energy range of 107-1010 eV. For higher energies the heliosphere bec…