We present the first spectroscopic confirmation of an ultramassive galaxy at redshift z\gt 3 using data from Keck-NIRSPEC, VLT-X-shooter, and GTC-Osiris. We...

We have observed 10 luminous blue stars in M 33 at intermediate dispersion and have determined spectral types and luminosity classes from the blue and red...

We have observed a number of the most luminous A and B supergiants in the galaxies M 31 and M 33 at intermediate dispersion obtaining both blue and red...

We present preliminary results of multi-object spectroscopy of new mid-, and far-infrared selected galaxies detected in the European Large Area ISO Survey...

The photometric and spectroscopic data of the sample galaxies were obtained at the very large telescope (VLT) of the European Southern Observatory (ESO) at...

Aims: We present optical photometry and spectroscopy of the afterglow and host galaxy of gamma-ray burst GRB 040924. This GRB had a rather short duration of T90...

We present optical spectra with high signal-to-noise ratio of 10 BL Lac objects detected at GeV energies by the Fermi satellite (3FGL catalog), which previous...

We present ground-based spectra of early-type star candidates in the Local Group galaxies M 33 and NGC 6822 taken at the 4.2 m William Herschel Telescope (La...

We have obtained spectra for 103 published globular cluster candidates in the Sculptor group galaxies NGC 253 and 55. On the basis of radial velocities and...