The Hamburg/SAO Survey for Emission-Line Galaxies

S.A. Pustilnik1 - D. Engels2 - A.V. Ugryumov1 - V.A. Lipovetsky1 - H.-J. Hagen2 - A.Yu. Kniazev1 - Yu.I. Izotov3 - G. Richter4

Special Astrophysical Observatory, Nizhnij Arkhyz, Karachai-Circessia, 357147, Russia - Hamburger Sternwarte, Gojenbergswerg 112, D-21029 Hamburg, Germany - Main Astronomical Observatory, Goloseevo, Kiev-22, 252650, Ukraine - Astrophysical Institute Potsdam, An der Sternwarte 16, Potsdam, D-14482, Germany

Abstract:

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/H II 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 6m Russian telescope. The main ELG candidate selection criteria applied are blue or flat enough continuum (near $\lambda$ 4000 Å) and the presence of strong or moderate [O III] $\lambda\lambda$ 4959,5007 Å emission lines recognized on digitized prism spectra of galaxies with the survey estimated B-magnitudes in the range $16^m - 19\fm5$ . 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/H II 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.

surveys - galaxies: fundamental parameters - galaxies: distances and redshifts - galaxies: starburst - galaxies: compact

**Table 1:** Journal of observations at the SAO 6m telescope
Run	Date			Instrument	Grating	Wavelength	Dispersion
No					[grooves/mm]	Range [Å]	[Å/pixel]
(1)	(2)			(3)	(4)	(5)	(6)

1	14	Dec	1995	CCD, SP-124	300	4600-7400	5.2
2	17	Dec	1995	CCD, SP-124	300	4000-7200	5.2
3	14	Jan	1996	CCD, SP-124	300	4000-7000	5.2
4	15-17	Jan	1996	CCD, SP-124	300	3800-7000	5.2
5	19-20	Feb	1996	CCD, SP-124	300	3800-7000	5.2
6	21-22	Feb	1996	CCD, SP-124	600	3800-5400	2.7
7	7-8	Oct	1996	CCD, SP-124	600	3700-6000	2.4
8	12-14	Nov	1996	CCD, LSS	650	3700-7000	3.1
9	16	Jan	1997	CCD, LSS	650	3700-5400	3.1
10	1	Dec	1997	CCD, SP-124	600	3700-6000	2.4
11	3-5	Apr	1998	CCD, SP-124	600	3700-6000	2.4
12	6	Apr	1998	CCD, SP-124	300	3700-8000	4.5
13	19	Apr	1998	CCD, SP-124	600	3700-7500	2.4
14	27	Apr	1998	CCD, SP-124	300	3700-8000	4.5
15	1-2	May	1998	CCD, SP-124	300	3600-8000	4.5
16	27-30	Jun	1998	CCD, SP-124	300	3700-8000	4.5