Search Publications
Fitting BICEP2 with defects, primordial gravitational waves and dust
Kunz, Martin; Liddle, Andrew R.; Lizarraga, Joanes +3 more
In this work we discuss the possibility of cosmic defects being responsible for the B-mode signal measured by the BICEP2 collaboration. We also allow for the presence of other cosmological sources of B-modes such as inflationary gravitational waves and polarized dust foregrounds, which might contribute to or dominate the signal. On the one hand, w…
Stochastic acceleration of ions driven by Pc1 wave packets
Sibeck, D. G.; Khazanov, G. V.; Tel'nikhin, A. A. +1 more
The stochastic motion of protons and He+ ions driven by Pc1 wave packets is studied in the context of resonant particle heating. Resonant ion cyclotron heating typically occurs when wave powers exceed 10-4 nT2/Hz. Gyroresonance breaks the first adiabatic invariant and energizes keV ions. Cherenkov resonances with t…
Special issue editorial - Plasma interactions with Solar System Objects: Anticipating Rosetta, Maven and Mars Orbiter Mission
Coates, A. J.; Yamauchi, M.; Wellbrock, A.
Within our solar system, the planets, moons, comets and asteroids all have plasma interactions. The interaction depends on the nature of the object, particularly the presence of an atmosphere and a magnetic field. Even the size of the object matters through the finite gyroradius effect and the scale height of cold ions of exospheric origin. It als…
The inner ∼ 40 pc radial distribution of the star formation rate for a nearby Seyfert 2 galaxy M51
Bian, Wei-Hao; He, Zhi-Cheng; Fang, Li-Ling +1 more
We investigate the spatially resolved specific star formation rate (SSFR) in the inner ∼40 pc for a nearby Seyfert 2 galaxy, M51 (NGC 5194) by analyzing spectra obtained with the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS). We present 24 radial spectra measured along the STIS long slit in M51, extending ∼ 1″ from the n…
Ultraviolet spectroscopic investigation of HU Aqr and AN UMa with the data from HST and IUE
Sanad, M. R.
We present ultraviolet spectroscopic study of two polar systems, HU Aqr and AN UMa, observed with the Hubble Space Telescope's Space Telescope Imaging Spectrograph (STIS) and Faint Object Spectrograph (FOS) and with the International Ultraviolet Explorer (IUE) during the period 1979--2003, to diagnose the ultraviolet fluxes of C IV 1550 Å and He I…
Rosetta mission: When the dust has settled
Jewitt, David
The Rosetta orbiter following Comet 67P has captured not only the public imagination but also actual dust grains from the comet's nucleus, revealing their composition, morphology and strength.
Introduction to the special issue on Venus exploration
Piccioni, G.; Wilson, C.; Svedhem, H.
Venus Express ended its mission in December 2014 after an extraordinary successful eight and a half years at Venus. The first years of the mission concentrated on the original objectives of the mission, namely to study the dynamics, structure and chemistry of the atmosphere, to investigate the plasma environment and its interaction with the solar …
Constraints on the birth of the universe and origin of cosmic dark flow
Garnavich, P.; Mathews, G. J.; Gangopadhyay, M. R. +4 more
We summarize three recent efforts to constrain the first few moments of cosmic creation before and during the epoch of inflation. We consider two means to explain a slight dip in the power spectrum of the cosmic microwave background for multipoles in the range of ℓ = 10-30 from both the Planck and WMAP data. We show that such a dip could be the re…
The Science of the Cluster Mission
Laakso, Harri; Goldstein, Melvyn L.; Escoubet, C. Philippe +6 more
Consistency relation for natural inflation with Planck 2015 data
Nozari, Kourosh; Kahvaee, H.; Rashidi, N.
We consider the cosine Natural inflation model that is a good candidate to explain the initial accelerating phase of the universe. By computing the inflationary parameters in Einstein frame, we construct a consistency relation between the scalar spectral index, tensor-to-scalar ratio, as well as the running of the scalar spectral index and compare…