Search Publications
Anisotropies in the HI gas distribution toward 3C 196
Kerp, J.; Kalberla, P. M. W.
Context. The local Galactic Hi gas was found to contain cold neutral medium (CNM) filaments that are aligned with polarized dust emission. These filaments appear to be dominated by the magnetic field and in this case turbulence is expected to show distinct anisotropies.
Aims: We use the Galactic Effelsberg-Bonn Hi Survey (EBHIS) to derive 2D …
Conditions for electron-cyclotron maser emission in the solar corona
Bloomfield, D. S.; Zucca, P.; Gallagher, P. T. +1 more
Context. The Sun is an active source of radio emission ranging from long duration radio bursts associated with solar flares and coronal mass ejections to more complex, short duration radio bursts such as solar S bursts, radio spikes and fibre bursts. While plasma emission is thought to be the dominant emission mechanism for most radio bursts, the …
Radical-induced chemistry from VUV photolysis of interstellar ice analogues containing formaldehyde
Danger, Grégoire; Chiavassa, Thierry; Duvernay, Fabrice +1 more
Surface processes and radical chemistry within interstellar ices are increasingly suspected to play an important role in the formation of complex organic molecules (COMs) observed in several astrophysical regions and cometary environments. We present new laboratory experiments on the low-temperature solid state formation of complex organic molecul…
GRB 980425 host: [C II], [O I], and CO lines reveal recent enhancement of star formation due to atomic gas inflow
Le Floc'h, E.; Sollerman, J.; Hunt, L. K. +18 more
Context. Accretion of gas from the intergalactic medium is required to fuel star formation in galaxies. We have recently suggested that this process can be studied using host galaxies of gamma-ray bursts (GRBs).
Aims: Our aim is to test this possibility by studying in detail the properties of gas in the closest galaxy hosting a GRB (980425). …
Herschel detects oxygen in the β Pictoris debris disk
Heras, A. M.; Walker, H. J.; Ivison, R. J. +28 more
The young star β Pictoris is well known for its dusty debris disk produced through collisional grinding of planetesimals, kilometre-sized bodies in orbit around the star. In addition to dust, small amounts of gas are also known to orbit the star; this gas is likely the result of vaporisation of violently colliding dust grains. The disk is seen edg…
ALMA-resolved salt emission traces the chemical footprint and inner wind morphology of VY Canis Majoris
Smith, N.; Decin, L.; Richards, A. M. S. +6 more
Context. At the end of their lives, most stars lose a significant amount of mass through a stellar wind. The specific physical and chemical circumstances that lead to the onset of the stellar wind for cool luminous stars are not yet understood. Complex geometrical morphologies in the circumstellar envelopes prove that various dynamical and chemica…
Oxygen, neon, and iron X-ray absorption in the local interstellar medium
García, Javier A.; Kallman, Timothy R.; Gatuzz, Efraín +1 more
Aims: We present a detailed study of X-ray absorption in the local interstellar medium by analyzing the X-ray spectra of 24 galactic sources obtained with the Chandra High Energy Transmission Grating Spectrometer and the XMM-Newton Reflection Grating Spectrometer.
Methods: By modeling the continuum with a simple broken power-law and by i…
CLASH-VLT: Strangulation of cluster galaxies in MACS J0416.1-2403 as seen from their chemical enrichment
Grillo, C.; Balestra, I.; Rosati, P. +9 more
Aims: Environmental effects gain importance as large scale structures in the Universe develop with time and have become the dominant mechanism for quenching galaxies of intermediate and low stellar masses at lower redshifts. Therefore, clusters of galaxies at z< 0.5 are the sites where environmental effects are expected to be more pronounc…
Water in star-forming regions with Herschel (WISH). VI. Constraints on UV and X-ray irradiation from a survey of hydrides in low- to high-mass young stellar objects
Liseau, R.; van Dishoeck, E. F.; Lis, D. C. +18 more
Context. Hydrides are simple compounds containing one or a few hydrogen atoms bonded to a heavier atom. They are fundamental precursor molecules in cosmic chemistry and many hydride ions have become observable in high quality for the first time thanks to the Herschel Space Observatory. Ionized hydrides such as CH+ and OH+ (an…
Asteroseismic versus Gaia distances: A first comparison
De Ridder, J.; Eyer, L.; Aerts, C. +1 more
Context. The Kepler space mission led to a large number of high-precision time series of solar-like oscillators. Using a Bayesian analysis that combines asteroseismic techniques and additional ground-based observations, the mass, radius, luminosity, and distance of these stars can be estimated with good precision. This has given a new impetus to t…