Search Publications
Kelvin-Helmholtz waves at the Earth's magnetopause: Multiscale development and associated reconnection
André, M.; Khotyaintsev, Y.; Vaivads, A. +11 more
We examine traversals on 20 November 2001 of the equatorial magnetopause boundary layer simultaneously at ∼1500 magnetic local time (MLT) by the Geotail spacecraft and at ∼1900 MLT by the Cluster spacecraft, which detected rolled-up MHD-scale vortices generated by the Kelvin-Helmholtz instability (KHI) under prolonged northward interplanetary magn…
The changing phases of extrasolar planet CoRoT-1b
de Mooij, Ernst J. W.; Albrecht, Simon; Snellen, Ignas A. G.
Hot Jupiters are a class of extrasolar planet that orbit their parent stars at very short distances. They are expected to be tidally locked, which can lead to a large temperature difference between their daysides and nightsides. Infrared observations of eclipsing systems have yielded dayside temperatures for a number of transiting planets. The day…
Less Than 10 Percent of Star Formation in z ~ 0.6 Massive Galaxies is Triggered by Major Interactions
Papovich, Casey; Bell, Eric F.; Somerville, Rachel S. +26 more
Both observations and simulations show that major tidal interactions or mergers between gas-rich galaxies can lead to intense bursts of star formation. Yet, the average enhancement in star formation rate (SFR) in major mergers and the contribution of such events to the cosmic SFR are not well estimated. Here we use photometric redshifts, stellar m…
Parameters of Herbig Ae/Be and Vega-type stars
Eiroa, C.; Montesinos, B.; Mora, A. +1 more
Context: This work presents the characterization of 27 young early-type stars, most of them in the age range 1-10 Myr, and three suspected hot companions of post-T Tauri stars belonging to the Lindroos binary sample. Most of these objects show IR excesses in their spectral energy distributions, which are indicative of the presence of disks. The wo…
Variable Polarization Measured in the Prompt Emission of GRB 041219A Using IBIS on Board INTEGRAL
Götz, Diego; Laurent, Philippe; Lebrun, François +2 more
Polarization measurements provide a direct insight into the nature of astrophysical processes. Unfortunately, only a few instruments are available for this kind of measurement at γ-ray energies, and the sources need to be very bright. Gamma-ray bursts (GRBs) are ideal candidates due to their large flux over limited time intervals, maximizing the a…
The Detection of Inside-Out Disk Growth in M33
Dolphin, Andrew E.; Williams, Benjamin F.; Holtzman, Jon +2 more
We present resolved stellar photometry of four fields along the major axis of the M33 disk from images taken with the Advanced Camera for Surveys aboard the Hubble Space Telescope. The photometry provides a detailed census of the red clump in all fields and reaches the ancient main sequence in the outermost field. Through detailed modeling of the …
Globular Cluster Systems in Giant Ellipticals: The Mass/Metallicity Relation
Harris, William E.
Data from the Hubble Space Telescope taken with the Advanced Camera for Surveys/WFC camera have been used to investigate the globular cluster (GC) populations around six giant elliptical galaxies that are ~40 Mpc distant. From these six fields, imaged in B and I, a total of more than 15,000 candidate GCs have been measured, of which 8000 or more a…
Structure of the Venus neutral atmosphere as observed by the Radio Science experiment VeRa on Venus Express
Tellmann, Silvia; Tyler, G. Leonard; Pätzold, Martin +2 more
The European Space Agency Venus Express Radio Science experiment (VeRa) obtained 118 radio occultation measurements of the Venusian atmosphere between July 2006 and June 2007. Southern latitudes are uniformly sampled; measurements in the northern hemisphere are concentrated near the pole. Radial profiles of neutral number density derived from the …
Extremely high reflection of solar wind protons as neutral hydrogen atoms from regolith in space
Barabash, Stas; Holmström, Mats; Futaana, Yoshifumi +7 more
We report on measurements of extremely high reflection rates of solar wind particles from regolith-covered lunar surfaces. Measurements by the Sub-keV Atom Reflecting Analyzer (SARA) instrument on the Indian Chandrayaan-1 spacecraft in orbit around the Moon show that up to 20% of the impinging solar wind protons are reflected from the lunar surfac…
Focusing Cosmic Telescopes: Exploring Redshift z ~ 5-6 Galaxies with the Bullet Cluster 1E0657 - 56
Treu, Tommaso; Bradač, Maruša; Applegate, Douglas +7 more
The gravitational potential of clusters of galaxies acts as a cosmic telescope allowing us to find and study galaxies at fainter limits than otherwise possible and thus probe closer to the epoch of formation of the first galaxies. We use the Bullet cluster 1E0657 - 56 (z = 0.296) as a case study, because its high mass and merging configuration mak…