Search Publications
XMM-Newton high-resolution spectroscopy reveals the chemical evolution of M 87
Böhringer, H.; Simionescu, A.; Kaastra, J. S. +3 more
We present a study of chemical abundances in the giant elliptical galaxy M 87 using high-resolution spectra obtained with the Reflection Grating Spectrometers during two deep XMM-Newton observations. While we confirm the two-temperature structure of the inter-stellar medium (ISM) in M 87, we also show that a continuous temperature distribution des…
Multifrequency VLBA monitoring of 3C 273 during the INTEGRAL Campaign in 2003. I. Kinematics of the parsec scale jet from 43 GHz data
Tornikoski, M.; Wiik, K.; Savolainen, T. +1 more
In this first of a series of papers describing polarimetric multifrequency Very Long Baseline Array (VLBA) monitoring of
Hubble Space Telescope observations of the nucleus and inner coma of comet 67P/Churyumov-Gerasimenko
Jorda, L.; Lamy, P. L.; Gutiérrez, P. J. +3 more
Context: .Following the postponement of the launch of the Rosetta spacecraft scheduled in January 2003, comet 67P/Churyumov-Gerasimenko emerged as the most suitable new target. However a critical issue was the size, that is, the mass of its nucleus, as the surface module Philae was designed to land on a nucleus with a radius no larger than approxi…
A hard X-ray view of giga-hertz peaked spectrum radio galaxies
Guainazzi, M.; Piconcelli, E.; Grandi, P. +3 more
We present the first broadband X-ray observations of four Giga-Hertz Peaked Spectrum (GPS) radio galaxies at redshift ⪉1 performed by Chandra and XMM-Newton. These observations more than double the number of members of this class with measured spectra in hard (E > 2 keV) X-rays. All sources were detected. Their radio-to-X-ray spectral energy di…
Unveiling the nature of INTEGRAL objects through optical spectroscopy. IV. A study of six new hard X-ray sources
Palazzi, E.; Masetti, N.; Walter, R. +9 more
We present further results from our onging optical spectrophotometric campaign at the Astronomical Observatory of Bologna in Loiano (Italy) on unidentified hard X-ray sources detected by INTEGRAL. We observed spectroscopically the putative optical counterparts of the INTEGRAL sources IGR J00234+6141, IGR J01583+6713, IGR J06074+2205, IGR J13091+11…
XMM-Newton X-ray spectroscopy of classical T Tauri stars
Schmitt, J. H. M. M.; Robrade, J.
We present results from a comparative study of XMM-Newton observations of four classical T Tauri stars (CTTS), namely
Simultaneous optical and X-ray observations of a giant flare on the ultracool dwarf LP 412-31
Liefke, C.; Schmitt, J. H. M. M.; Micela, G. +1 more
Cool stars are known to produce flares probably as a result of the magnetic reconnection in their outer atmospheres. We present simultaneous XMM-Newton optical V band and X-ray observations of the M8 dwarf LP 412-31. During the observation a giant flare occurred, with an optical amplitude of 6 mag and total energy of 3 × 1032 erg in bot…
Amorphous alumina in the extended atmosphere of α Orionis
Waters, L. B. F. M.; Eriksson, K.; Hony, S. +7 more
In this paper we study the extended atmosphere of the late-type supergiant α Orionis. Infrared spectroscopy of red supergiants reveals strong molecular bands, some of which do not originate in the photosphere but in a cooler layer of molecular material above it. Lately, these layers have been spatially resolved by near and mid-IR interferometry. I…
COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses. II. SDSS J0924+0219: the redshift of the lensing galaxy, the quasar spectral variability and the Einstein rings
Magain, P.; Dye, S.; Meylan, G. +4 more
Aims.To provide the observational constraints required to use the gravitationally lensed quasar SDSS J0924+0219 for the determination of H0 from the time delay method. We measure here the redshift of the lensing galaxy, we show the spectral variability of the source, and we resolve the lensed host galaxy of the source.
Methods.We pr…
Resolving the compact dusty discs around binary post-AGB stars using N-band interferometry
Waters, L. B. F. M.; Jaffe, W.; Paresce, F. +8 more
We present the first mid-IR long baseline interferometric observations of the circumstellar matter around binary post-AGB stars. Two objects,