The effects that interactions produce on galaxy disks and how they modify the subsequent formation of bars need to be distinguished to fully understand the...
The nature and origin of substructure in the outskirts of M31 - II. Detailed star formation histories
While wide-field surveys of M31 have revealed much substructure at large radii, understanding the nature and origin of this material is not straightforward from...
The Nature and Size of the Optical Continuum Source in QSO 2237+0305
From the peak of a gravitational microlensing high-magnification event in the A component of QSO 2237+0305, which was accurately monitored by the Gravitational...
The nature of 500 micron risers - II. Multiplicities and environments of sub-mm faint dusty star-forming galaxies
We present Submillimeter Common User Bolometer Array 2 (SCUBA-2) and Submillimeter Array (SMA) follow-up observations of four candidate high-redshift dusty star...
The nature of 500 micron risers I: SMA observations
We present SMA observations at resolutions from 0.35 to 3 arcsec of a sample of 34 candidate high redshift dusty star forming galaxies (DSFGs). These sources...
The nature of arms in spiral galaxies. II. The sample
We present here the results of an imaging study of eight grand-design and two intermediate-arm galaxies, based on CCD observations in U, B, V, R and I. We give...
The nature of arms in spiral galaxies. III. Azimuthal profiles
In this paper we analyse the structure of a small sample of galaxies using a set of CCD images in standard photometric bands presented in a previous paper (del...
The nature of arms in spiral galaxies. IV. Symmetries and asymmetries
A Fourier analysis of the intensity distribution in the planes of nine spiral galaxies is performed. In terms of the arm classification scheme of cite[Elmegreen...
The Nature of Close Companions of the BL Lacertae Objects 1ES 0502+675 and 1ES 1440+122
We report on deep radio images and optical spectroscopy of two BL Lac objects that have very close compact companions. The two targets, 1ES 0502+675 and 1ES...