Search Publications
Discovery of a new Wolf-Rayet star and a candidate star cluster in the Large Magellanic Cloud with Spitzer
Gruendl, R. A.; Sander, A.; Hamann, W. -R. +8 more
We report the first-ever discovery of a Wolf-Rayet (WR) star in the Large Magellanic Cloud via detection of a circular shell with the Spitzer Space Telescope. Follow-up observations with Gemini-South resolved the central star of the shell into two components separated from each other by ≈2 arcsec (or ≈0.5 pc in projection). One of these components…
Revealing a new symbiotic X-ray binary with Gemini Near-infrared Integral Field Spectrograph
Bahramian, Arash; Heinke, Craig O.; Wijnands, Rudy +3 more
We use K-band spectroscopy of the counterpart to the rapidly variable X-ray transient XMMU J174445.5-295044 to identify it as a new symbiotic X-ray binary. XMMU J174445.5-295044 has shown a hard X-ray spectrum (we verify its association with an INTEGRAL/Imager on-Board the INTEGRAL Satellite 18-40 keV detection in 2013 using a short Swift/X-Ray Te…
Searching for visual companions of close Cepheids. VLT/NACO lucky imaging of Y Oph, FF Aql, X Sgr, W Sgr, and η Aql
Kervella, P.; Mérand, A.; Girard, J. H. V. +4 more
Aims: High-resolution imaging in several photometric bands can provide color and astrometric information of the wide-orbit component of Cepheid stars. Such measurements are needed to understand the age and evolution of pulsating stars. In addition, binary Cepheids have the potential to provide direct and model-independent distances and masses…
Coronal Mass Ejections Observed at the Total Solar Eclipse on 13 November 2012
Hanaoka, Yoichiro; Nakazawa, Jun; Ohgoe, Osamu +2 more
White-light observations of the total solar eclipse on 13 November 2012 were made at two sites, where the totality occurred 35 min apart. The structure of the corona from the solar limb to a couple of solar radii was observed with a wide dynamic range and a high signal-to-noise ratio. An ongoing coronal mass ejection (CME) and a pre-CME loop struc…
Low-mass X-Ray Binaries and Globular Clusters Streamers and Arcs in NGC 4278
Fabbiano, G.; D'Abrusco, R.; Brassington, N. J.
We report significant inhomogeneities in the projected two-dimensional spatial distributions of low-mass X-ray binaries (LMXBs) and globular clusters (GCs) of the intermediate mass elliptical galaxy NGC 4278. In the inner region of NGC 4278, a significant arc-like excess of LMXBs extending south of the center at ~50'' in the western side of the ga…
Unveiling the environment surrounding low-mass X-ray binary SAX J1808.4-3658
Kaastra, J. S.; Costantini, E.; Fabian, A. C. +2 more
Context. Low-mass X-ray binaries (LMXBs) are a natural workbench to study accretion disk phenomena and optimal background sources to measure elemental abundances in the interstellar medium (ISM). In high-resolution XMM-Newton spectra, the LMXB SAX J1808.4-3658 in the past showed a neon column density significantly higher than expected given its sm…
Constraining the depth of Saturn’s zonal winds by measuring thermal and gravitational signals
Fletcher, Leigh N.; Liu, Junjun; Schneider, Tapio
Based on straightforward dynamical considerations, we show how available and upcoming measurements of Saturn’s thermal and gravitational signals can be used to constrain the depth to which its zonal winds penetrate. The dynamical considerations issue from the facts that Saturn has a strong intrinsic heat flux, rotates rapidly, and has negligible a…
Multiscale analysis of Galactic dust emission using complex wavelet transforms - I. Separation of Gaussian and non-Gaussian fluctuations in Herschel observations
Miville-Deschênes, M. -A.; Joncas, G.; Robitaille, J. -F.
We use anisotropic complex wavelet transforms to make a multiscale analysis of the distribution of fluctuations of dust emission at 250 µm from the Herschel infrared Galactic Plane Survey of the Herschel Space Observatory. By reproducing the Fourier power spectrum with complex wavelet transforms we show that different power distributions at …
Latitudinal structure of the Venus O2 infrared airglow: A signature of small-scale dynamical processes in the upper atmosphere
Drossart, P.; Piccioni, G.; Gérard, J. -C. +1 more
Images of the nightside limb of Venus have been obtained in the northern hemisphere with the VIRTIS multispectral infrared imager on board Venus Express between April 2006 and October 2008. We analyze the latitudinal distribution of the O2(a1Δ) airglow limb profiles at 1.27 µm to characterize its distribution and variab…
O2(a1Δg) dayglow limb observations on Mars by SPICAM IR on Mars-Express and connection to water vapor distribution
Montmessin, F.; Bertaux, J. -L.; Fedorova, A. A. +3 more
The 1.27-µm O2(a1Δg) dayglow on Mars is a product of the ozone photolysis by solar UV radiation. The intensity of the O2(a1Δg) emission rate depends on ozone concentration, atmospheric density and kinetic parameters of involved photochemical reactions. In turn, the distributio…