Search Publications
The Analyser of Space Plasmas and Energetic Atoms (ASPERA-4) for the Venus Express mission
Coates, A. J.; Kallio, E.; Fedorov, A. +43 more
The general scientific objective of the ASPERA-4 (Analyser of Space Plasmas and Energetic Atoms) experiment is to study the solar wind-atmosphere interaction and characterise the plasma and neutral gas environment in the near-Venus space through energetic neutral atom (ENA) imaging and local charged particle measurements. The studies to be perform…
A new calibration of Galactic Cepheid period-luminosity relations from B to K bands, and a comparison to LMC relations
Arriagada, P.; McArthur, B. E.; Benedict, G. F. +8 more
Context: The universality of the Cepheid period-luminosity (PL) relations has been under discussion since metallicity effects were assumed to play a role in the value of the intercept and, more recently, of the slope of these relations.
Aims: The goal of the present study is to calibrate the Galactic PL relations in various photometric bands (…
Quiet-Sun Internetwork Magnetic Fields from the Inversion of Hinode Measurements
Lites, B. W.; Ichimoto, K.; Bellot Rubio, L. R. +10 more
We analyze Fe I 630 nm observations of the quiet Sun at disk center taken with the spectropolarimeter of the Solar Optical Telescope aboard the Hinode satellite. A significant fraction of the scanned area, including granules, turns out to be covered by magnetic fields. We derive field strength and inclination probability density functions from a M…
The Inner Jet of the Radio Galaxy M87
Kellermann, K. I.; Kovalev, Y. Y.; Lister, M. L. +1 more
We report new 2 cm VLBA images of the inner radio jet of M87 showing a limb-brightened structure and unambiguous evidence for a faint 3 mas long counterfeature which also appears limb brightened. Multiepoch observations of seven separate jet features show typical speeds of less than a few percent of the speed of light, despite the highly asymmetri…
The ACS Survey of Galactic Globular Clusters: M54 and Young Populations in the Sagittarius Dwarf Spheroidal Galaxy
Anderson, Jay; Dotter, Aaron; Majewski, Steven R. +11 more
As part of the ACS Survey of Galactic Globular Clusters, we present new Hubble Space Telescope photometry of the massive globular cluster M54 (NGC 6715) and the superposed core of the tidally disrupted Sagittarius (Sgr) dSph galaxy. Our deep (F606W ~ 26.5), high-precision photometry yields an unprecedentedly detailed color-magnitude diagram showin…
Coronal Pseudostreamers
Sheeley, N. R., Jr.; Wang, Y. -M.; Rich, N. B.
In a recent study of the 2006 solar eclipse, we noted that there are two kinds of coronal streamers: ``helmet streamers,'' which separate coronal holes of opposite magnetic polarity, and ``pseudostreamers,'' which overlie twin loop arcades and separate holes of the same polarity. It is well known that the heliospheric plasma and current sheets rep…
Venus Express—The first European mission to Venus
Barabash, S.; Pätzold, M.; Zhang, T. L. +24 more
Venus Express is the first European mission to planet Venus. The mission aims at a comprehensive investigation of Venus atmosphere and plasma environment and will address some important aspects of the surface physics from orbit. In particular, Venus Express will focus on the structure, composition, and dynamics of the Venus atmosphere, escape proc…
Emergence of Small-Scale Magnetic Loops in the Quiet-Sun Internetwork
Kubo, M.; Ichimoto, K.; Tsuneta, S. +11 more
We study the emergence of magnetic flux at very small spatial scales (less than 2") in the quiet-Sun internetwork. To this aim, a time series of spectropolarimetric maps was taken at disk center using the instrument SP/SOT on board Hinode. The LTE inversion of the full Stokes vector measured in the Fe I 6301 and 6302 Å lines allows us to retrieve …
Transient Coronal Sigmoids and Rotating Erupting Flux Ropes
van Driel-Gesztelyi, L.; Török, T.; Green, L. M. +2 more
To determine the relationship between transient coronal (soft X-ray or EUV) sigmoids and erupting flux ropes, we analyse four events in which a transient sigmoid could be associated with a filament whose apex rotates upon eruption and two further events in which the two phenomena were spatially but not temporally coincident. We find the helicity s…
Astrophysical supplements to the ASCC-2.5: Ia. Radial velocities of ∼55000 stars and mean radial velocities of 516 Galactic open clusters and associations
Scholz, R. -D.; Piskunov, A. E.; Kharchenko, N. V. +2 more
We present the 2nd version of the Catalogue of Radial Velocities with Astrometric Data (CRVAD-2). This is the result of the cross-identification of stars from the All-Sky Compiled Catalogue of 2.5 Million Stars (ASCC-2.5) with the General Catalogue of Radial Velocities and with other recently published radial velocity lists and catalogues. The CRV…