The measurement of Doppler velocity shifts in spectra is a ubiquitous theme in astronomy, usually handled by computing the cross-correlation of the signals and finding the location of its maximum. This paper addresses the problem of the determination of wavelength or velocity shifts among multiple spectra of the same, or very similar, objects. We

The velocity field of the nearly face-on galaxy NGC 3631 is derived from observations in the Hα line on the 6-m telescope of the Special Astrophysical Observatory. These optical data are compared with radio observations of this galaxy (Knapen 1997). It is argued that the two-armed spiral structure of NGC 3631 has a wave nature, and that the

PSR B1951+32 is a gamma -ray pulsar detected by the Energetic Gamma Ray Experiment Telescope (EGRET) and identified with the 39.5 ms radio pulsar in the supernova remnant CTB 80. The pulsar energy spectrum is consistent with an unbroken power law with differential photon index of -1.8 +/- 0.1 between 50 MeV and 10 GeV. The EGRET data shows no

As part of a systematic survey for the search of high velocity gas in giant extragalactic H II regions, the authors have observed the five largest and brightest H II regions in M101. They have found two types of peculiar emission profiles: (1) a broadening of the Hα emission line at low intensity, in excess of the values expected for the typical

Here is a state-of-the-art review of our current knowledge of brown dwarfs and very low-mass stars. The hunt for, and study of, these elusive objects is currently one of the most dynamic areas of research in astronomy. This volume presents review articles from a team of international authorities who assess the spectacular progress in this field in

We report the detections of a giant planet (MARVELS-7b) and a brown dwarf (BD) candidate (MARVELS-7c) around the primary star in the close binary system, HD 87646. To the best of our knowledge, it is the first close binary system with more than one substellar circumprimary companion that has been discovered. The detection of this giant planet was