Radio Astrophysics

Stellar Radio Astrophysics

Radio emission has been detected from all the stages of stellar evolution across the HR Diagram. Its presence reveals both astrophysical phenomena and stellar activity which, otherwise, would not be detectable by other means. The development of large, sensitive interferometers has allowed us to resolve the radio structure of several stellar systems, providing insights into the mass transfer pro...

ASTRONOMY AND ASTROPHYSICS The radio continuum halo of NGC 5775

Sensitive, scaled-array VLA radio-continuum observations of the edge-on galaxy NGC 5775, at 6 and 20 cm, show evidence of a radio-continuum halo that is detected up to 10–15 kpc above and below the plane. In addition, the presence of a radio continuum bridge connecting NGC 5775 to neighbouring NGC 5774 is confirmed, lending further support to reports that these galaxies form an interacting pair...

ASTROPHYSICS The origin of the radio emission from β Lyrae

In this paper we present new observational evidence that supports the presence of an extra source of continuum emission in the binary system β Lyrae. New VLA and IRAM observations, together with published data from the literature and ISO archive data, allow us to build the Spectral Energy Distribution of the binary between 5 × 10 9 Hz and 5 × 10 15 Hz. The radio-millimeter part of the spectrum ...

Astrophysics.

Using the oscillation frequencies of α Cen A recently discovered by Bouchy & Carrier (2001, 2002), the available astrometric, photometric and spectroscopic data, we tried to improve the calibration of the visual binary system α Cen. With the revisited masses of Pour-baix et al. (2002) we do not succeed to obtain a solution satisfying all the seismic observational constraints. Relaxing the const...

Astrophysics.