Search Publications
Constraining hybrid natural inflation with recent CMB data
Hidalgo, Juan Carlos; Vázquez, J. Alberto; Carrillo-González, Mariana +2 more
We study the Hybrid Natural Inflation (HNI) model and some of its realisations in the light of recent CMB observations, mainly Planck temperature and WMAP-9 polarization, and compare with the recent release of BICEP2 dataset. The inflationary sector of HNI is essentially given by the potential V(ϕ) = V0(1+acos(ϕ/f)), where a is a positi…
“Dust, Ice, and Gas In Time” (DIGIT) Herschel Observations of GSS30-IRS1 in Ophiuchus
Lee, Jeong-Eun; Green, Joel D.; Je, Hyerin +2 more
As a part of the “Dust, Ice, and Gas In Time” (DIGIT) key program on Herschel, we observed GSS30-IRS1, a Class I protostar located in Ophiuchus (d = 120 pc), with Herschel/Photodetector Array Camera and Spectrometer. More than 70 lines were detected within a wavelength range from 50 to 200 µ m, including CO, H2O, OH, and two atomi…
Non-local scalar fields inflationary mechanism in light of Planck 2013
Sheikhahmadi, Haidar; Ghorbani, Soheyla; Saaidi, Khaled
A generalization of the canonical and non-canonical theory of inflation is introduced in which the kinetic energy term in action is written as non-local term. The inflationary universe within the framework of considering this non-locality will be studied. To investigate the effects of non-locality on the inflationary parameters we consider two wel…
Constraints on the Surface Magnetic Fields and Age of a Cool Hypergiant: XMM-Newton X-Ray Observations of VY CMa
Humphreys, Roberta M.; Davidson, Kris; Kastner, Joel H. +2 more
The complex circumstellar ejecta of highly evolved, cool hypergiants are indicative of multiple, asymmetric mass-loss events. To explore whether such episodic, non-isotropic mass loss may be driven by surface magnetic activity, we have observed the archetypical cool hypergiant VY CMa with the XMM-Newton X-ray satellite observatory. The hypergiant …
Detection of small-scale folds at a solar wind reconnection exhaust
Eastwood, J. P.; Hietala, H.; Mistry, R.
of reconnection in the solar wind over the last few years appear to indicate that the majority of large-scale reconnecting current sheets are roughly planar, and that reconnection itself is quasi-steady. Most studies of solar wind exhausts have used spacecraft with large separations and relatively low time cadence ion measurements. Here we present…
Coronal Radio Occultation Experiments with the Helios Solar Probes: Correlation/Spectral Analysis of Faraday Rotation Fluctuations
Pätzold, M.; Bird, M. K.; Efimov, A. I. +4 more
The coronal Faraday rotation (FR) experiments using the linearly polarized signals of the Helios-1 and Helios-2 interplanetary probes remain a unique investigation of the magnetic field of the solar corona and its aperiodic and quasi-periodic variations. The unexpectedly long lifetime of these spacecraft (1974 - 1986) enabled studies from very dee…
Auroral spirals at Saturn
Roussos, E.; Bonfond, B.; Gérard, J. -C. +4 more
We report observations of auroral spirals at Saturn propagating from midnight to noon via dawn, based on Cassini/UVIS measurements. The aurora during that sequence is observed for the first time to consist of detached features swirling as they propagate from dawn to early afternoon. The features have a diameter of ∼6000 km in the ionosphere, which…
Short-term variability of inner-source pickup ions at 1 AU. SOHO/CELIAS observations
Wimmer-Schweingruber, R. F.; Berger, L.; Drews, C. +1 more
Context. In 1995 a second extended source of pickup ions in the inner heliosphere was discovered. Since then this so-called inner source has been characterised in many studies, and various scenarios for its nature have been proposed. But to this day, the detailed nature of the inner source is still unknown.
Aims: Although it seems most likely…
Statistical characteristics of slow earthward and tailward flows in the plasma sheet
Dunlop, M. W.; Baumjohann, W.; Rème, H. +3 more
In this paper, we statistically analyzed and compared the earthward flow (EF) and the tailward flow (TF) in the plasma sheet. It is found that the properties of the EF/TF in the central plasma sheet (CPS) of β > 1 and the outer plasma sheet (OPS) of 0.1 < β < 1 are distinctly different. The main conclusions include that (1) the EFs occur …
Spectroscopic characterization of X-ray emitting young stars associated with the Sh 2-296 nebula
Montmerle, T.; Gregorio-Hetem, J.; Fernandes, B. +1 more
We studied a sample of stars associated with the Sh 2-296 nebula, part of the reflection nebulae complex in the region of Canis Major R1 (CMa R1). Our sample corresponds to optical counterparts of X-ray sources detected from observations with the XMM-Newton satellite, which revealed dozens of possible low-mass young stars not yet known in this reg…