Search Publications
XMM-Newton discovery of soft X-ray absorption in the high-z superluminous Blazar RBS 315
Guainazzi, M.; Piconcelli, E.
We present the analysis and the results of a 20 ks XMM-Newton observation of the extremely X-ray loud (LX ≈ 5 × 1047 erg s-1) flat-spectrum radio quasar RBS 315 at a redshift of 2.69. This EPIC observation has allowed us to strongly constrain the slope of the continuum (Γ = 1.23±0.01) as well as to discover the pre…
Is Arcturus a well-understood K giant?. Test of model atmospheres and potential companion detection by near-infrared interferometry
Eriksson, K.; Decin, L.; Verhoelst, T. +8 more
We present near-IR interferometric measurements of the K1.5 giant Arcturus (α Bootis), obtained at the IOTA interferometer with the FLUOR instrument, in four narrow filters with central wavelengths ranging from 2.03 µm to 2.39 µm. These observations were expected to allow us to quantify the wavelength dependence of the diameter of a ty…
ADAS analysis of the differential emission measure structure of the inner solar corona. II. A study of the "quiet Sun" inhomogeneities from SOHO CDS-NIS spectra
Lanzafame, A. C.; Brooks, D. H.; Lang, J.
We present a study of the differential emission measure (DEM) of a “quiet Sun” area observed in the extreme ultraviolet at normal incidence by the Coronal Diagnostic Spectrometer (CDS) on the SOHO spacecraft. The data used for this work were taken using the NISATS observing sequence. This takes the full wavelength ranges from both the N…
The 3-D shaping of NGC 6741: A massive, fast-evolving Planetary Nebula at the recombination-reionization edge
Sabbadin, F.; Turatto, M.; Cappellaro, E. +2 more
We infer the gas kinematics, diagnostics and ionic radial profiles, distance and central star parameters, nebular photo-ionization model, spatial structure and evolutionary phase of the Planetary Nebula NGC 6741 by means of long-slit ESO NTT+EMMI high-resolution spectra at nine position angles, reduced and analysed according to the tomographic and…
The proper motion of the Magellanic Clouds: The UCAC2-Hipparcos inconsistency
Momany, Y.; Zaggia, S.
Using the USNO CCD Astrograph all-sky Catalog (UCAC2), we measure the mean proper motion of the two Magellanic Clouds. Appropriately-selected LMC populations show a proper motion <µα,µδ>≃(+0.84,+4.32) that is significantly higher, in <µδ>, than currently accepted Hipparcos-like values; <µα,µδ>≃(+1.94…
Determination of confusion noise for far-infrared measurements
Lemke, D.; Klaas, U.; Kiss, Cs.
We present a detailed assessment of the far-infrared confusion noise imposed on measurements with the ISOPHOT far-infrared detectors and cameras aboard the ISO satellite. We provide confusion noise values for all measurement configurations and observing modes of ISOPHOT in the 90 µm ≤ λ ≤ 200 µm wavelength range. Based on these results…
Out of the darkness: the infrared afterglow of the INTEGRAL burst GRB 040422 observed with the VLT
Covino, S.; D'Avanzo, P.; Campana, S. +15 more
Investigating the EGRET-radio galaxies link with INTEGRAL: The case of 3EG J1621+8203 and NGC 6251
Guainazzi, M.; Grenier, I. A.; Grandi, P. +10 more
The analysis of an INTEGRAL AO2 observation of the error contours of the EGRET source 3EG J1621+8203 is presented. The only source found inside the error contours for energies between 20 and 30 keV at 5σ detection significance is the FR I radio galaxy NGC 6251. This supports the identification of NGC 6251 with 3EG J1621+8203. The observed flux is …
Photographic observations of solar system bodies at the Engelhardt astronomical observatory
Rizvanov, N.; Nefedjev, Ju.
We describe a large database of photographic observations of Solar System bodies obtained at the Engelhadt Astronomical Observatory (EnAO). We give a brief description of the methods of observations and the accuracy of their reduction with the PPM and Tycho-2 catalogues. The photographic positions of the major planets, except Jupiter, are in the s…
Search for radiative pumping lines of OH masers. I. The 34.6 m absorption line towards 1612 MHz OH maser sources
Szczerba, R.; Sobolev, A. M.; Chen, P. S. +1 more
The 1612 MHz hydroxyl maser in circumstellar envelopes has long been thought to be pumped by 34.6 µm photons. Only recently, the Infrared Space Observatory has made possible spectroscopic observations which enable the direct confirmation of this pumping mechanism in a few cases. To look for the presence of this pumping line, we have searched…