A spectroscopic atlas of the HgMn star HD 175640 (B9 V) λλ 3040-10 000 Å

Abstract

We present a high resolution spectral atlas of the HgMn star HD 175640 covering the 3040-10000 A region. UVES spectra observed with 90 000-110 000 resolving power and signal to noise ratio ranging from 200 to 400 are compared with a synthetic spectrum computed with the SYNTHE code (Kurucz 1993b). The model atmosphere is an ATLAS 12 model (Kurucz 1997) with parameters T eff = 12 000 K, log g = 3.95, = 0 km s-1. The stellar individual abundances in ATLAS 12 were derived from an iterative procedure. The starting atomic line lists downloaded from the Kurucz website have been improved and extended by examining different sources in the literature and by comparing the computed profiles with the observed spectrum. The high quality of the data allowed us to study the isotopic and hyperfine structure for several lines of Mn II, Ga II, Ba II, Pt II, Hg I, and Hg II. Numerous weak emission lines from Cr I and Ti II have been identified in the red part of the spectrum, starting at ≈λ 5847 Å. Two emission lines of CI (mult. 10, mult. 9) have been observed for the first time. All Cr II and Ti II emission lines originate from the high excitation states (Xlow ≳ 89 000 cm-1 for Cr II andXlow ≳ 62 000 cm-1 for Ti II) with large transition probabilities (log gf > -1.00). The synthetic spectrum superimposed on the observed spectrum as well as the adopted improved atomic line lists are available at the CDS and http://wwwuser.oat. ts.astro.it/ castelli/stars.html. An extended discussion on each identified ion and related atomic data is available both on the quoted website and in an electronic Appendix to the paper.