Search Publications
Water in low-mass star-forming regions with Herschel. The link between water gas and ice in protostellar envelopes
van Dishoeck, E. F.; Walsh, C.; Kristensen, L. E. +4 more
Aims: Our aim is to determine the critical parameters in water chemistry and the contribution of water to the oxygen budget by observing and modelling water gas and ice for a sample of eleven low-mass protostars, for which both forms of water have been observed.
Methods: A simplified chemistry network, which is benchmarked against more s…
The chromosphere above sunspots at millimeter wavelengths
Solanki, S. K.; White, S. M.; Loukitcheva, M.
Aims: The aim of this paper is to demonstrate that millimeter wave data can be used to distinguish between various atmospheric models of sunspots, whose temperature structure in the upper photosphere and chromosphere has been the source of some controversy.
Methods: We use observations of the temperature contrast (relative to the quiet S…
Release timescales of solar energetic particles in the low corona
Vainio, R.; Valtonen, E.; Klein, K. -L. +14 more
Aims: We present a systematic study of the timing and duration of the release processes of near-relativistic (NR; >50 keV) electrons in the low corona.
Methods: We analyze seven well-observed events using in situ measurements by both the ACE and Wind spacecraft and context electromagnetic observations in soft X-rays, radio, hard X-ray…
Optical Observations of the Type Ic Supernova 2007gr in NGC 1058
Filippenko, Alexei V.; Li, Weidong; Wang, Xiaofeng +6 more
We present extensive optical observations of the normal Type Ic supernova (SN) 2007gr, spanning from about one week before maximum light to more than one year thereafter. The optical light and color curves of SN 2007gr are very similar to those of the broad-lined Type Ic SN 2002ap, but the spectra show remarkable differences. The optical spectra o…
Parameters of cosmological models and recent astronomical observations
Sharov, G. S.; Vorontsova, E. G.
For different gravitational models we consider limitations on their parameters coming from recent observational data for type Ia supernovae, baryon acoustic oscillations, and from 34 data points for the Hubble parameter H(z) depending on redshift. We calculate parameters of 3 models describing accelerated expansion of the universe: the ΛCDM model,…
The spectral catalogue of INTEGRAL gamma-ray bursts. results of the joint IBIS/SPI spectral analysis
Götz, D.; Bošnjak, Ž.; Bouchet, L. +2 more
We present the updated INTEGRAL catalogue of gamma-ray bursts (GRBs) observed between December 2002 and February 2012. The catalogue contains the spectral parameters for 59 GRBs localized by the INTEGRAL Burst Alert System (IBAS). We used the data from the two main instruments on board the INTEGRAL satellite: the spectrometer SPI (SPectrometer on …
Geologic map of the northern hemisphere of Vesta based on Dawn Framing Camera (FC) images
Russell, Christopher T.; Williams, David A.; Jaumann, Ralf +9 more
The Dawn Framing Camera (FC) has imaged the northern hemisphere of the Asteroid (4) Vesta at high spatial resolution and coverage. This study represents the first investigation of the overall geology of the northern hemisphere (22-90°N, quadrangles Av-1, 2, 3, 4 and 5) using these unique Dawn mission observations. We have compiled a morphologic ma…
Shock-Cloud Interaction and Particle Acceleration in the Southwestern Limb of SN 1006
Miceli, M.; Bocchino, F.; Decourchelle, A. +3 more
The supernova remnant SN 1006 is a powerful source of high-energy particles and evolves in a relatively tenuous and uniform environment despite interacting with an atomic cloud in its northwestern limb. The X-ray image of SN 1006 reveals an indentation in the southwestern part of the shock front and the H I maps show an isolated (southwestern) clo…
Salpeter Normalization of the Stellar Initial Mass Function for Massive Galaxies at z ~ 1
Cappellari, Michele; Shetty, Shravan
The stellar initial mass function (IMF) is a key parameter for studying galaxy evolution. Here we measure the IMF mass normalization for a sample of 68 field galaxies in the redshift range 0.7-0.9 within the Extended Groth Strip. To do this we derive the total (stellar + dark matter) mass-to-light [(M/L)] ratio using axisymmetric dynamical models.…
The impact of sloshing on the intragroup medium and old radio lobe of NGC 5044
Vrtilek, Jan M.; David, Laurence P.; O'Sullivan, Ewan
We present temperature and abundance maps of the central 125 kpc of the NGC 5044 galaxy group, based on a deep XMM-Newton observation. The abundance map reveals an asymmetrical abundance structure, with the centroid of the highest abundance gas offset ∼22 kpc north-west of the galaxy centre, and moderate abundances extending almost twice as far to…