The Hamburg/SAO Survey for Emission–Line Galaxies

Abstract

Abstract. We present first results 1 of the Hamburg/SAO Survey for Emission-Line Galaxies (HSS therein, SAOSpecial Astrophysical Observatory, Russia) which is based on the digitized objective-prism photoplates database of the Hamburg Quasar Survey (HQS). The main goal of this survey is the search for emission-line galaxies (ELG) in order to create a new deep sample of blue compact galaxies (BCG) in a large sky area. Another important goal of this work is to search for new extremely low-metallicity galaxies. We present the first results of spectroscopy obtained with the 2.2 m telescope at the German-Spanish Observatory at Calar Alto, and with the 6 m telescope at the Russian Special Astrophysical Observatory. The primary ELG candidate selection criteria applied were a blue continuum (near λ 4000Å) and the presence of emission lines close to λ 5000Å recognized on digitized prism spectra of galaxies with magnitudes in the range B = 16. m 0 − 19. m 5. The spectroscopy resulted in the detection or/and quantitative spectral classification of 74 emission-line objects. Of them 55 are newly discovered, and 19 were already known as galaxies before. 11 of the latter have redshifts and are known ELGs. For most of the known galaxies emission line ratios were measured for the first time and an improved classification is presented. 47 objects are classified as BCGs, one as Sy2 galaxy, six as possible LINERs, and four as new QSOs.Send offprint requests to: and@sao.ru Deceased September 22, 1996. 1 Tables 1 to 5 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.htmlThe remaining galaxies do not show significant Hβ and [Oiii] λλ 4959, 5007Å emission lines, and are likely either low-ionization starburst or dwarf amorphous nuclear starburst galaxies.

The Hamburg/SAO Survey for low metallicity blue compact H II galaxies (HSS–LM)

“…The classification criteria applied follow those of Salzer (1989a). Here Salzer's classes SS, DHIIH and HIIH are taken together as one class of blue compact/HII galaxies (BCG) (see also Ugryumov et al 1999).…”

“…The selection procedure used in the HSS is described in detail by Ugryumov et al (1999). The main difference introduced in the HSS-LM is a more strict criterion on the strength of emission-line features in the full-resolution objective prism spectra.…”

Mapping Extremely Low Metallicity Galaxies to Redshift One

“…Historically, objective prism surveys have been used to select emission-line galaxies for low-metallicity studies (e.g., the Hamburg QSO Survey [ Popescu et al 1996] and its HSS sequel [Ugryumov et al 1999] that discovered HS 2134+0400 [Pustilnik et al 2006] and the Kitt Peak International Spectroscopy Survey [KISS; Salzer et al 2000;Melbourne & Salzer 2002]). The advantage of using the objective prism technique rather than the continuum selection, employed with the SDSS ( Kniazev et al 2003) or DEEP2 surveys ( Hoyos et al 2005), is that they have a higher efficiency and provide a more uniform selection.…”

The Hamburg/SAO survey for emission–line galaxies

“…For a description of the BCGs found in these two surveys, see Izotov et al (1993aIzotov et al ( , 1993b, Thuan et al (1994) and Pustilnik et al (1995) for the SBS and Salzer et al (1995), Ugryumov (1997), Ugryumov et al (1998) for the Case survey which is still in progress.…”

“…The basic ideas of the HSS and its selection methods of ELG candidates are described along with the first results of the follow-up spectroscopy in Ugryumov et al (1999) (Paper I). The final selection was slightly modified to improve significantly the detection rate of ELGs in follow-up spectroscopy as described in Paper II.…”