Search Publications
The distance to NGC 1316 (Fornax A): yet another curious case
Della Valle, M.; Blakeslee, J. P.; Cantiello, M. +6 more
Aims: The distance of NGC 1316, the brightest galaxy in the Fornax cluster, provides an interesting test for the cosmological distance scale. First, because Fornax is the second largest cluster of galaxies within ≲25 Mpc after Virgo and, in contrast to Virgo, has a small line-of-sight depth; and second, because NGC 1316 is the single galaxy w…
Spatial distribution of water in the stratosphere of Jupiter from Herschel HIFI and PACS observations
Lara, L. M.; Hartogh, P.; Lellouch, E. +11 more
Context. In the past 15 years, several studies suggested that water in the stratosphere of Jupiter originated from the Shoemaker-Levy 9 (SL9) comet impacts in July 1994, but a direct proof was missing. Only a very sensitive instrument observing with high spectral/spatial resolution can help to solve this problem. This is the case of the Herschel S…
The asymmetric drift, the local standard of rest, and implications from RAVE data
Watson, F.; Munari, U.; Steinmetz, M. +13 more
Context. The determination of the local standard of rest (LSR), which corresponds to the measurement of the peculiar motion of the Sun based on the derivation of the asymmetric drift of stellar populations, is still a matter of debate. The classical value of the tangential peculiar motion of the Sun with respect to the LSR was challenged in recent…
BL Lacertae identifications in a ROSAT-selected sample of Fermi unidentified objects
Palazzi, E.; Sbarufatti, B.; Minniti, D. +15 more
The optical spectroscopic followup of 27 sources belonging to a sample of 30 high-energy objects selected by positionally cross correlating the first Fermi/LAT Catalog and the ROSAT All-Sky Survey Bright Source Catalog is presented here. It has been found or confirmed that 25 of them are BL Lacertae objects (BL Lacs), while the remaining two are G…
Evidence of quasi-chemically homogeneous evolution of massive stars up to solar metallicity
Martins, F.; Mahy, L.; Russeil, D. +1 more
Context. Long soft gamma-ray bursts (LGRBs) are usually associated with the death of the most massive stars. A large amount of core angular momentum in the phases preceding the explosion is required to form LGRBs. A very high initial rotational velocity can provide this angular momentum. This velocity strongly influences the way the star evolves: …
Long-term variability of extragalactic radio sources in the Planck Early Release Compact Source Catalogue
Dickinson, C.; López-Caniego, M.; Partridge, B. +5 more
Combining measurements taken using the Wilkinson Microwave Anisotropy Probe (WMAP) from 2001 to 2008 with measurements taken using Planck from 2009 to 2010, we investigate the long-term flux density variability of extragalactic radio sources selected from the Planck Early Release Compact Source Catalogue. The single-year, single-frequency WMAP map…
Spatially extended OH+ emission from the Orion Bar and Ridge
Ossenkopf, V.; Nagy, Z.; Bergin, E. A. +5 more
Context. The reactive HnO+ ions (OH+, H2O+ and H3O+) are widespread in the interstellar medium and act as precursors to the H2O molecule. While HnO+ absorption is seen on many Galactic lines of sight, active galactic nuclei often show the …
Improved methods for determining the kinematics of coronal mass ejections and coronal waves
Long, D. M.; Bloomfield, D. S.; Habbal, S. R. +5 more
Context. The study of solar eruptive events and associated phenomena is of great importance in the context of solar and heliophysics. Coronal mass ejections (CMEs) and coronal waves are energetic manifestations of the restructuring of the solar magnetic field and mass motion of the plasma. Characterising this motion is vital for deriving the dynam…
The 2XMMi/SDSS Galaxy Cluster Survey. II. The optically confirmed cluster sample and the LX - T relation
Takey, A.; Schwope, A.; Lamer, G.
Aims: We compile a sample of X-ray-selected galaxy groups and clusters from the XMM-Newton serendipitous source catalogue (2XMMi-DR3) with optical confirmation and redshift measurement from the Sloan Digital Sky Survey (SDSS). We present an analysis of the X-ray properties of this new sample with particular emphasis on the X-ray luminosity-te…
HDO and SO2 thermal mapping on Venus. II. The SO2 spatial distribution above and within the clouds
Encrenaz, T.; Atreya, S. K.; Bézard, B. +6 more
Sulfur dioxide and water vapor, two key species of Venus photochemistry, are known to exhibit significant spatial and temporal variations above the cloud top. In particular, ground-based thermal imaging spectroscopy at high spectral resolution, achieved on Venus in January 2012, has shown evidence for strong SO2 variations on timescales…