The Hamburg/SAO survey for emission-line galaxies . II. The second list of 128 galaxies

We present the second part of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAO - Special Astrophysical Observatory, Russia) which is based on the digitized objective-prism photoplates database of the Hamburg Quasar Survey (HQS). The main goal of the project is the search for emission-line galaxies (ELG) in order to create a new deep sample of blue compact/Hii galaxies (BCG) in a large sky area. Another important goal of this work is to search for new extremely low-metallicity galaxies. In this paper we present new results of spectroscopy obtained with the 6 m Russian telescope. The main ELG candidate selection criteria applied are blue or flat enough continuum (near lambda 4000 Ä) and the presence of strong or moderate [Oiii] lambda lambda 4959, 5007 Ä emission lines recognized on digitized prism spectra of galaxies with the survey estimated B-magnitudes in the range 16() m - 19fm5 . No other criteria were applied. The spectroscopy resulted in detection and quantitative spectral classification of 134 emission-line objects. For 121 of them the redshifts are determined for the first time. For 13 ELGs known before emission line ratios are presented at first time. 108 of 134 emission-line objects are classified as BCG/Hii galaxies and probable BCGs, 6 - as QSOs, 1 - as Seyfert galaxy, 1 - as super-association in a dwarf spiral galaxy, 2 - as probable LINERs, 14 are low excitation objects - either of starburst nuclei (SBN), or dwarf amorphous nuclei starburst galaxy (DANS) type, and 2 - nonclassified. 23 galaxies did not show significant emission lines. The five most metal-deficient BCGs discovered have oxygen abundances log(O/H)+12 in the range 7.4 to 7.7, similar to the most metal-deficient BCGs known before. Tables 2 to 6 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html. Figures A1 to A13 will be made available only in the electronic version of the journal. Appendix A is only available at http://www.edpsciences.com