Search Publications
Nonlinear interaction of 3D kinetic Alfvén wave and whistler wave in solar wind plasmas
Sharma, R. P.; Gaur, Nidhi
In the present work, the nonlinear evolution of 3D kinetic Alfvén wave (KAW) has been investigated in solar wind plasmas. By taking the adiabatic response of background density the nonlinearity arises because of ponderomotive effects. The dynamical equations governing the dynamics of 3D KAW and whistler are obtained. We have performed the numerica…
Determination of coronal magnetic fields from 10 to 26R⊙ using the density compression ratios of CME-driven shocks
Moon, Y. -J.; Shanmugaraju, A.; Suresh, K.
Recently, the estimation of coronal magnetic field using new methods, such as standoff distance method or density compression ratio method has been reported. In the present work, we utilized the density compression ratio of CME-driven shocks for 10 events at 29 different locations in the upper solar corona (10–26R⊙) and determined the c…
Study of plasma flow reversal in the near-Earth plasma sheet using numerical computations
Kondoh, Koji; Shimizu, Tohru
Tailward flow in the near-Earth plasma sheet associated with a rebound of the earthward bursty bulk flow (BBF) is investigated using three-dimensional magnetohydrodynamics simulations of magnetic reconnection in the magnetotail on the basis of the spontaneous fast reconnection model. In order to investigate the properties of this tailward flow, vi…
Philae’s 64 hours of comet science yield rich data
Gibney, Elizabeth
Comet lander is now hibernating, but has already altered our understanding of these objects.
Possible signature of Alfvén wave dissipation in the localized magnetic funnels of the equatorial solar corona
Dwivedi, Bhola N.; Mohan, Anita; Srivastava, Abhishek Kumar
We analyse the Hinode/EIS 2″-spectroscopic scan data containing the spectral line formed at typical inner coronal temperature. The strong Fe XII 195.120 Å line shows the existence of funnel-like expanding flux-tubes which exhibit the signature of blue-/red-shifted plasma motions in the off-limb equatorial corona. These coronal funnels expand in th…
In-flight calibration of the HIFI diplexers
Mueller, Michael; Teyssier, David; Delforge, Bertrand +4 more
HIFI is a heterodyne spectrometer aboard the Herschel Space Observatory, providing high-spectral-resolution capabilities. Of its seven frequency bands, four (bands 3, 4, 6, and 7) employ Martin-Puplett diplexers to combine sky signal and local oscillator at the two linear polarizations H and V, prior to feeding them into the mixers (receivers). Th…
Single-event upsets in the Cluster and Double Star Digital Wave Processor instruments
Walker, S. N.; Yearby, K. H.; Balikhin, M.
Radiation-induced upsets are an important issue for electronic circuits operating in space. Upsets due to solar protons, trapped protons, and galactic cosmic rays are frequently observed. Modeling the expected frequency of upsets is a necessary part of the design process for space hardware. The Cluster and Double Star spacecraft were respectively …
Origin of collapsed pits and branched valleys surrounding the Ius chasma on Mars
Vinod Kumar, K.; Vamshi, G. T.; Martha, T. R.
Chasma is a deep, elongated and steep sided depression on planetary surfaces. Several hypothesis have been proposed regarding the origin of chasma. In this study, we analysed morphological features in north and south of Ius chasma. Collapsed pits and branched valleys alongwith craters are prominent morphological features surrounding Ius Chasma, wh…
Constraint on the cosmic age from the solar r-process abundances
Heng, T. H.; Xu, X. D.; Niu, Z. M. +2 more
The cosmic age is an important physical quantity in cosmology. Based on the radiometric method, a reliable lower limit of the cosmic age is derived to be 15.68+/- 1.94 Gyr, using the r-process abundances inferred for the solar system and observations in metal-poor stars. If the central value is taken, this value is larger than the latest cosmic ag…
Probing the evolution of galaxy clusters with the SZ effect
Lapi, A.; Cavaliere, A.
In galaxy clusters the thermal Sunyaev-Zel'dovich (SZ) effect from the hot intracluster medium (ICM) provides a direct, self-contained measure of the pressure integrated over crossing lines of sight, that is intrinsically independent of redshift and well suited for evolutionary studies. We show in detail how the size of the effect and its pattern …