Search Publications
Sub-arcsecond imaging of the radio continuum and neutral hydrogen in the Medusa merger
Aalto, S.; Beswick, R. J.; Hüttemeister, S. +1 more
We present sub-arcsecond, Multi-Element Radio Linked Interferometer (MERLIN) observations of the decimetre radio continuum structure and neutral hydrogen (Hi) absorption from the nuclear region of the starburst galaxy NGC 4194 (the Medusa Merger). The continuum structure of the central kiloparsec of the Medusa has been imaged, revealing a pair of …
The recurrent ultra-luminous X-ray transient NGC 253 ULX1
Pietsch, W.; Bauer, M.
We present the results of ROSAT and XMM-Newton observations of the recurrent ultraluminous X-ray source (ULX)
Helioseismic evidence of two solar granulation timescales
Vázquez Ramió, H.; Roca Cortés, T.; Régulo, C.
The signature of two different scales of solar granulation in the power spectrum of disk integrated irradiance time series is presented. The fitted timescales for granulation (τGR1≈ 237~s and τGR2≈ 62~s) are in good agreement with the characteristic lifetimes derived from recent image time series of the Sun's surface (Del Mor…
The EUV variability of the luminous QSO HS 1700+6416
Shull, J. M.; Kriss, G. A.; Reimers, D. +2 more
We report on the first observations of variations in UV (intrinsic EUV 330 Å) flux of the luminous QSO HS 1700+6416 (z = 2.72) over a decade. The amplitude of variations increases from ±0.1 mag in the optical (R) to up to a factor of 3 at 1250 Å. This is apparently an extension of the increase in amplitude of variations towards shorter wavelengths…
ISO observations of the Wolf-Rayet galaxies NGC 5430, NGC 6764, Mrk 309 and VII Zw 19
McBreen, B.; Metcalfe, L.; O'Halloran, B. +2 more
Observations of four WR galaxies (NGC 5430, NGC 6764, Mrk 309 and VII Zw 19) using the Infrared Space Observatory are presented here. ISOCAM maps of NGC 5430, Mrk 309 and NGC 6764 revealed the location of star formation regions in each of these galaxies. ISOPHOT spectral observations from 4 to 12 µm detected the ubiquitous PAH bands in the n…
Spitzer's large CO2 ice detection toward the L723 class 0 object
Dartois, E.; Thi, W. -F.; Muñoz Caro, G. M. +1 more
The L723 low mass class 0 protostellar object has been observed with the IRS low resolution spectrometer onboard Spitzer Space Telescope. A huge CO2 ice column density of 6.3 ± 1 × 1018 cm-2 is detected toward this extremely red object. We constructed the spectral energy distribution (SED) of L723 by combining the Spitzer spe…
GRB 040403: A faint X-ray rich gamma-ray burst discovered by INTEGRAL
Frontera, F.; Hurley, K.; Götz, D. +13 more
GRB 040403 is one of the faintest gamma-ray bursts for which a rapid and accurate localization has been obtained. Here we report on the gamma-ray properties of this burst, based on observations with the IBIS instrument aboard INTEGRAL, and the results of searches for its optical afterglow. The steep spectrum (power law photon index = 1.9 in the 20…
The extragalactic Cepheid bias: significant influence on the cosmic distance scale
Paturel, G.; Teerikorpi, P.
The unique measurements with the Hubble Space Telescope of Cepheid variable stars in nearby galaxies led to extragalactic distances that made the HST Key Project conclude that the Hubble constant is H0 = 72 km s-1 Mpc-1. The idea that H0 is now known is widely spread among the astronomical community. Som…
First detections of the cataclysmic variable AE Aquarii in the near to far infrared with ISO and IRAS: Investigating the various possible thermal and non-thermal contributions
de Martino, D.; Schulz, B.; Fender, R. +13 more
We have used ISO to observe the Magnetic Cataclysmic Variable AE Aquarii in the previously unexplored range from 4.8 µm up to 170 µm in the framework of a coordinated multi-wavelength campaign from the radio to optical wavelengths. We have obtained for the first time a spectrum between 4.8 and 7.3 µm with ISOCAM and ISOPHOT-P: th…
BS Indi: An enigmatic object in the Tucana association
Guenther, E. W.; Alcalá, J. M.; Esposito, M. +2 more
BS Ind (=HD 202947) is a young K0V star in the Tucana association. Photometric observations with the Hipparcos satellite show an eclipse-like light-curve with primary and secondary eclipse. The eclipsing binary has a period of 0.435338 days and a circular orbit. Our spectroscopic observations however show that the K0V primary is a single-line spec…