Results 111 to 120 of about 1,203,998 (246)

Multifrequency Very Long Baseline Array Observations of the Compact Double B2 2050+36: Constraints on Interstellar Scattering Revisited [PDF]

, 2001
We present multifrequency observations with the Very Long Baseline Array of the compact double radio source B2 2050+36. Our observations are at 0.33, 0.61, 1.67, 2.3, and 8.4 GHz, with the 0.61 GHz observations forming the third epoch of observation of ...
T. Lazio, A. Fey
semanticscholar   +1 more source

Interstellar Scattering and the Sizes of Astronomical Masers

The Astrophysical Journal, 1972
The suggestion is explored that scattering by inhomogeneities in the distribution of electrons causes astronomical masers to appear larger than their actual sizes. It is shown that neither scattering near the source nor scattering in the intervening medium is sufficiently strong to produce this effect.
Robert W. Boyd, Michael W. Werner
openaire   +1 more source

State of the Early Career Profession in Space Physics and Aeronomy: Climatological Survey Results

Journal of Geophysical Research: Space Physics, Volume 131, Issue 4, April 2026.
Abstract The American Geophysical Union (AGU) Space Physics & Aeronomy (SPA) section comprises scientists who study the Sun, solar wind, and planetary magnetospheres, ionospheres, and thermospheric/mesospheric systems along with their interconnections.
R. C. Allen, B. Gallardo‐Lacourt, S. Raptis, C. R. Gilly, L. C. Gasque, B. L. Alterman, J. C. Buitrago‐Casas, E. P. Macho, G. Malhotra, R. M. McGranaghan, P. Mostafavi, S. K. Vines   +11 more
wiley   +1 more source

Influence of Mars Topography on Radiation Dose Detected by the Mars Science Laboratory and Assessment of Mars Surface Albedo Radiation

Journal of Geophysical Research: Planets, Volume 131, Issue 4, April 2026.
Abstract The Radiation Assessment Detector (RAD) on the Curiosity rover has been characterizing the Martian surface radiation field since 2012. The dose observed by RAD is influenced by a variety of factors, including an essential one, the terrain. After parking near Murray Buttes in September 2016 where it first detected a ∼5% decrease in dose rate ...
Jingnan Guo, Changqi Tian, Gabin Charpentier, Robert F. Wimmer‐Schweingruber, Salman Khaksarighiri, Lu Pan, Jan Leo Löwe, Bent Ehresmann, Donald M. Hassler, Cary Zeitlin, Daniel Matthiä, Thomas Berger, Günther Reitz   +12 more
wiley   +1 more source

An investigation of the active galaxies M82 and NGC 5128 [PDF]

, 1995
In this thesis we present multi-waveband imaging polarimetry and spectropolarime- try of the starburst galaxy M82 and multi-waveband imaging polarimetry of the active galaxy NGC 5128. A review of previous studies of these galaxies is given.
Foley, Neasa
core  

Refractive and diffractive scattering in the interstellar medium

The Astrophysical Journal, 1986
Radio wave propagation through electron-density fluctuations in the ISM is studied. Observable propagation effects are explored using a one-dimensional thin-screen model for the turbulent medium. Diffraction caused by stochastic small-scale irregularities is combined with refraction from deterministic large-scale irregularities. Some of the effects are
J. M. Cordes, A. Pidwerbetsky, R. V. E. Lovelace   +2 more
openaire   +1 more source

Interstellar Scattering Towards the Galactic Center as Probed by OH/IR Stars [PDF]

, 1992
Angular broadening measurements are reported of 20 OH/IR stars near the galactic center. This class of sources is known to have bright, intrinsically compact (less than or equal to 20 mas) maser components within their circumstellar shells. VLBA antennas
Vanlangevelde, Huib Jan, Frail, Dale A., Cordes, James M., Diamond, Philip J.   +3 more
core   +1 more source

NE2025: An Updated Electron Density Model for the Galactic Interstellar Medium

The Astrophysical Journal
Free electrons in the Galactic interstellar medium (ISM) disperse and scatter coherent radio waves, by amounts that depend on the distance to the radio source.
Stella Koch Ocker, James M. Cordes
doaj   +1 more source

Redeveloping a CLEAN Deconvolution Algorithm for Scatter-broadened Radio Pulsar Signals

The Astrophysical Journal
Broadband radio waves emitted from pulsars are distorted and delayed as they propagate toward the Earth due to interactions with the free electrons that compose the interstellar medium (ISM), with lower radio frequencies being more impacted than higher ...
Olivia Young, Michael T. Lam
doaj   +1 more source

Including Interstellar Scattering Effects in Pulsar Timing [PDF]

, 2017
The NANOGrav collaboration aims to detect low frequency gravitational waves by measuring the arrival times of radio signals from pulsars. A confirmation of such a gravitational wave signal requires timing tens of pulsars with a precision of less than 100
Turner, Jacob
core