Search Publications
Formation of pebble-pile planetesimals
Johansen, Anders; Wahlberg Jansson, Karl
Asteroids and Kuiper belt objects are remnant planetesimals from the epoch of planet formation. The first stage of planet formation is the accumulation of dust and ice grains into mm- and cm-sized pebbles. These pebbles can clump together through the streaming instability and form gravitationally bound pebble clouds. Pebbles inside such a cloud wi…
Ultraviolet to infrared emission of z > 1 galaxies: Can we derive reliable star formation rates and stellar masses?
Morrison, G.; Buat, V.; Boquien, M. +6 more
Aims: Our knowledge of the cosmic mass assembly relies on measurements of star formation rates (SFRs) and stellar masses (Mstar), of galaxies as a function of redshift. These parameters must be estimated in a consistent way with a good knowledge of systematics before studying their correlation and the variation of the specific SFR.…
TANAMI blazars in the IceCube PeV-neutrino fields
Gehrels, N.; Thompson, D. J.; Wilms, J. +39 more
The IceCube Collaboration has announced the discovery of a neutrino flux in excess of the atmospheric background. Owing to the steeply falling atmospheric background spectrum, events at PeV energies most likely have an extraterrestrial origin. We present the multiwavelength properties of the six radio-brightest blazars that are positionally coinci…
Variation in the dust emissivity index across M 33 with Herschel and Spitzer (HerM 33es)
Boquien, M.; Braine, J.; van der Werf, P. +12 more
We study the wavelength dependence of the dust emission as a function of position and environment across the disk of M 33 using Spitzer and Herschel photometric data. M 33 is a Local Group spiral with slightly subsolar metallicity, which makes it an ideal stepping-stone to less regular and lower-metallicity objects such as dwarf galaxies and, prob…
Herschel view of the large-scale structure in the Chamaeleon dark clouds
Prusti, T.; Pilbratt, G. L.; André, Ph. +17 more
Context. The Chamaeleon molecular cloud complex is one of the nearest star-forming sites and encompasses three molecular clouds (Cha I, II, and III) that have a different star-formation history, from quiescent (Cha III) to actively forming stars (Cha II), and one that reaches the end of star-formation (Cha I).
Aims: We aim at characterising t…
LOFAR tied-array imaging of Type III solar radio bursts
Magdalenić, J.; McKean, J. P.; Eislöffel, J. +82 more
Context. The Sun is an active source of radio emission which is often associated with energetic phenomena such as solar flares and coronal mass ejections (CMEs). At low radio frequencies (<100 MHz), the Sun has not been imaged extensively because of the instrumental limitations of previous radio telescopes.
Aims: Here, the combined high sp…
Revisiting the transits of CoRoT-7b at a lower activity level
Aigrain, S.; Alonso, R.; Bordé, P. +29 more
The first super-Earth with measured radius discovered was CoRoT-7b and it has opened the new field of rocky exoplanet characterisation. To better understand this interesting system, new observations were taken with the CoRoT satellite. During this run 90 new transits were obtained in the imagette mode. These were analysed together with the previou…
An ALMA Early Science survey of molecular absorption lines toward PKS 1830-211. Analysis of the absorption profiles
Menten, K. M.; Combes, F.; Horellou, C. +17 more
We present the first results of an ALMA spectral survey of strong absorption lines for common interstellar species in the z = 0.89 molecular absorber toward the lensed blazar PKS 1830-211. The dataset brings essential information on the structure and composition of the absorbing gas in the foreground galaxy. In particular, we find absorption over …
Influence of physical galaxy properties on Lyα escape in star-forming galaxies
Hayes, Matthew; Schaerer, Daniel; Östlin, Göran +4 more
Context. Among the different observational techniques used to select high-redshift galaxies, the hydrogen recombination line Lyman-alpha (Lyα) is of particular interest because it gives access to the measurement of cosmological quantities such as the star formation rate (SFR) of distant galaxy populations. However, interpreting this line and calib…
Neutral interstellar He parameters in front of the heliosphere 1994-2007
Bzowski, M.; Witte, M.; Banaszkiewicz, M. +3 more
Context. A recent analysis of IBEX measurements of the neutral interstellar He flux showed that the inflow velocity vector is different from the results of an earlier analysis of observations from the GAS instrument onboard Ulysses. A recently published compilation of published results on the helium inflow direction from the past ~40 years suggest…