The optical to near-infrared (300 – 2500 nm) spectrum of the candidate massive young stellar object (YSO) B275, embedded in the star-forming region M17, has been observed with X-shooter on the ESO Very Large Telescope. The spectrum includes both photospheric absorption lines and emission features (H I and Ca II triplet emission lines, first and second overtone CO bandhead emission), as well as ...

This paper addresses the question, what does the spectrum of a typical quasar reveal about the velocity structure within its broad emission line region clouds? Turbulent (i.e., nonthermal) broadening of spectral lines can be due to macroturbulence or microturbulence. Microturbulence a†ects line formation and the emitted spectrum and may be required to account for the observed smoothness of the ...

The Na iD lines at 5890/5896 Å are very prominent features in the spectrum of late-type stars. Nevertheless, little attention has been devoted to the potential use of those lines as chromospheric diagnostics. As a case study, we explore the dependence on chromospheric activity of the D lines in a star with Teff = 3700 K, log g = 4.7 and solar metallicity. The results are compared with the bette...

Near-infrared spectra with a resolution of lambda&solm0;Deltalambda approximately 1100 in the rest-wavelength range of 1.8-2.2 µm have been obtained for a complete sample of 33 ultraluminous infrared galaxies (ULIRGs). Of the 33 objects observed, two show evidence of a central active galactic nucleus (AGN) through either a broad Paschen-alpha line or emission in the 1.963 µm fine structure of [...

The Na i D lines at 5890/5896 A are very prominent features in the spectrum of late-type stars. Nevertheless , little attention has been devoted to the potential use of those lines as chromospheric diagnostics. As a case study, we explore the dependence on chromospheric activity of the D lines in a star with T ee = 3700 K, logg = 4:7 and solar metallicity. The results are compared with the bett...