Search Publications
A research on the force-freeness of photosphere magnetic field
Hao, J.; Liu, S.
In this paper, the statistical studies on the force-freeness of photosphere magnetic fields are given. The studies are based on the vector magnetic fields observed by Solar Optical Telescope/Spectro-Polarimeter (SOT/SP) on board Hinode. Three parameters (Fx /Fp,Fy /Fp , and Fz /Fp) …
CONSERT line-of-sight link budget simulator
Plettemeier, Dirk; Kofman, Wlodek; Herique, Alain +4 more
In bistatic radar systems utilizing elliptical polarization on both the sending and receiving side, great care must be taken to correctly calculate the received power, as a mismatch in polarization may incur significant additional losses. In this paper, we present a method to simulate the link budget of the CONSERT instrument aboard the Rosetta mi…
The distance to the Galactic center determined by A–F stars
Branham, Richard L.
The distance from the sun to the center of the Galaxy
Gamma rays and cosmic rays at Venus: The Pioneer Venus gamma ray detector and considerations for future measurements
Lorenz, Ralph D.; Lawrence, David J.
We draw attention to, and present a summary archive of the data from, the Pioneer Venus Orbiter Gamma-ray Burst Detector (OGBD), an instrument not originally conceived with Venus science in mind. We consider the possibility of gamma-ray flashes generated by lightning and model the propagation of gamma rays in the Venusian atmosphere, finding that …
Was Comet C/1945 X1 (DU Toit) a Dwarf, SOHO-like Kreutz Sungrazer?
Sekanina, Zdenek; Kracht, Rainer
The goal of this investigation is to reinterpret and upgrade the astrometric and other data on comet C/1945 X1, the least prominent among the Kreutz system sungrazers discovered from the ground in the twentieth century. The central issue is to appraise the pros and cons of a possibility that this object is—despite its brightness reported at discov…
Better Alternatives to "Astronomical Silicate": Laboratory-based Optical Functions of Chondritic/Solar Abundance Glass with Application to HD 161796
Speck, A. K.; Pitman, K. M.; Hofmeister, A. M.
“Astronomical” or “circumstellar” silicate optical functions (real and imaginary indices of refraction n(λ ) and k(λ )) have previously been derived from compositionally and structurally disparate samples; past values were compiled from different sources in the literature, and are essentially kluges of observational, laboratory, and extrapolated o…
Statistical and Scaling Features of Fluctuations in the Dissipation Range During a Reconnection Event
Consolini, G.; Marcucci, M. F.; Pallocchia, G. +2 more
Reconnection events in space plasmas are accompanied by the occurrence of large-amplitude turbulent fluctuations of the magnetic and electric field, covering a wide range of temporal and spatial scales. Here, we study the scaling and statistical features of magnetic and electric field fluctuations below the ion-gyroperiod (i.e., in the dissipation…
Structural Parameters for 10 Halo Globular Clusters in M33
Ma, Jun
In this paper, we present the properties of 10 halo globular clusters (GCs) with luminosities L ≃ 5-7 × 105 L⊙ in the Local Group galaxy M33 using images from the Hubble Space Telescope WFPC2 in the F555W and F814W bands. We obtained the ellipticities, position angles, and surface brightness profiles for each GC. In general, …
On the Size and Mass of Photoionized Clouds in Extended Spiral Galaxy Halos
Danforth, Charles W.; Stocke, John T.; Keeney, Brian A. +1 more
The size and mass of two circumgalactic medium (CGM) clouds in the halo (impact parameter = 65 kpc) of a nearby late-type galaxy, MGC-01-04-005 ({cz}=1865 {km} {{{s}}}-1), are investigated using a close triplet of QSO sight lines (the “LBQS Triplet”). Far ultraviolet spectra obtained with the Cosmic Origins Spectrograph on board the Hub…
Cold galaxies
Clements, David L.; Rowan-Robinson, Michael
We use 350 µm angular diameter estimates from Planck to test the idea that some galaxies contain exceptionally cold (10-13 K) dust, since colder dust implies a lower surface brightness radiation field illuminating the dust, and hence a greater physical extent for a given luminosity. The galaxies identified from their spectral energy distribu…