Search Publications
Multi-wavelength observations of a nearby multi-phase interstellar cloud
Boulanger, F.; Falgarone, E.; Le Bourlot, J. +3 more
Aims: High-resolution spectroscopic observations (UV HST/STIS and optical) are used to characterize the physical state and velocity structure of the multiphase interstellar medium seen towards the nearby (170 pc) star HD 102065. The star is located behind the tail of a cometary-shaped, infrared cirrus-cloud, in the area of interaction between the …
Stellar mass estimates in early-type galaxies from lensing+dynamical and photometric measurements
Grillo, C.; Rosati, P.; Lombardi, M. +1 more
Aims:Our purpose is to compare two different diagnostics for estimating stellar masses in early-type galaxies and to establish their level of reliability. In particular, we consider the well-studied sample of 15 field elliptical galaxies selected from the Sloan Lens ACS (SLACS) Survey (z = 0.06-0.33). We examine here the correlation between the st…
Improved estimates of the physical properties of the O-star binary V1007 Sco = HD 152248 and notes on several other binaries in the NGC 6231 cluster
Wolf, M.; Morrell, N.; Harmanec, P. +4 more
Context: In spite of the importance of massive O-type stars for astrophysics, their accurate masses and other fundamental properties are still a matter of debate. Determining them reliably is hampered by various factors (stellar winds and other forms of circumstellar matter), and the agreement of derived properties with the model predictions is fa…
The plasma filling factor of coronal bright points. Coronal bright points
Dere, K. P.
Aims: We determine the volumetric plasma filling factor of coronal bright points.
Methods: Rastered spectra of the regions of the quiet Sun were recorded by the Extreme ultraviolet Imaging Spectrometer (EIS) during operations with the Hinode satellite. Calibrated intensities of Fe XII lines were obtained and images of the quiet corona were con…
Nuclear activity in nearby galaxies. Mid-infrared imaging with the VLT
Pantin, E.; Siebenmorgen, R.; Moorwood, A. +7 more
Aims: Dust enshrouded activity can be studied ideally by mid-infrared (MIR) observations. To explore the active galactic nuclei (AGN) versus star forming origin of the nuclear MIR emission of galaxies, observations of high spatial resolution are required. We report on 11.3 µm observations with VISIR at the VLT, which reach 0.35'' spatial res…
XMM-Newton and Chandra observations of the globular cluster NGC 6388
Guainazzi, M.; Nucita, A. A.; Carpano, S. +2 more
Context: By studying the optical brightness surface density of the globular cluster NGC 6388, it has been recently proposed that it harbors a central intermediate-mass black hole with mass ≃ 5.7×103 M⊙.
Aims: We expect that the compact object in the center of NGC 6388 emits radiation in the X-ray band as a consequence of …
Multi-conjugate adaptive optics images of the Trapezium cluster
Martín, E. L.; Huélamo, N.; Bouy, H. +3 more
Context: Multi-conjugate adaptive optics (MCAO) combine the advantages of both standard adaptive optics, which provide high contrast and high spatial resolution, and of wide field imaging (≈1'). Up to recently, MCAO for astronomy was limited to laboratory experiments. In this paper, we present the first scientific results obtained with the first M…
A coronal explosion on the flare star CN Leonis
Liefke, C.; Schmitt, J. H. M. M.; Reiners, A. +4 more
We present simultaneous high-temporal and high-spectral resolution observations of the nearby flare star CN Leo at optical and soft X-ray wavelengths. During our observing campaign a major flare occurred, raising the star's instantaneous energy output by almost three orders of magnitude. The flare shows the often observed impulsive behavior, with …
Combined Chandra, XMM-Newton, and Hubble Space Telescope observations of the Galactic globular cluster NGC 2808
Knigge, C.; Long, K. S.; Servillat, M. +6 more
Aims: Using new Chandra X-ray observations and existing XMM-Newton X-ray and Hubble far ultraviolet observations, we aim to detect and identify the faint X-ray sources belonging to the Galactic globular cluster
Methods: We present a Chandra X-r…
Discovery of photospheric Ca X emission lines in the far-UV spectrum of the hottest known white dwarf (KPD 0005+5106)
Rauch, T.; Werner, K.; Kruk, J. W.
For the first time, we have identified photospheric emission lines in the far-UV spectrum of a white dwarf. They were discovered in the Far Ultraviolet Spectroscopic Explorer spectrum of the hot (T eff ≈ 200 000 K) DO white dwarf KPD 0005+5106 and they stem from extremely highly ionized calcium (Ca X λλ 1137, 1159 Å). Their photospheric…