**Table 2:** Parameters of strong emission lines.
ESO-LV	Sample &	F(H $\beta$ ) $\times$ 10^-15	F([OIII]5007) $\times$ 10^-15	F(H $\alpha$ ) $\times$ 10^-15	F([NII]6583) $\times$ 10^-15	EW(H $\alpha$ )	Type of
name	Morph.	ergs cm^-2 s^-1	ergs cm^-2 s^-1	ergs cm^-2 s^-1	ergs cm^-2 s^-1	Å	Activity
(1)	(2)	(3)	(4)	(5)	(6)	(7) $^{\dagger}$	(8)
0310050	CS 3.5	4.0	0.3	15.0	8.2	8.2	HII
1060120	CS 6	10.2	1.5	38.0	18.0	12.4	HII
1080130	HDS 3.5	7.2	0.6	41.0	15.0	14.2	HII
1190190	HDS 5	5.7	1.3	12.0	6.7	5.5	HII
1420500	CS 5	10.0	2.8	20.0	16.0	3.0	L
1460090	CS 5	21.0	5.1	60.0	31.0	5.6	HII
1570050	HDS 5.5	14.5	4.4	53.0	17.0	27.9	HII
2010220	CS 5	12.0	8.8	45.8	13.1	16.6	HII
2030180	CS 4	45.4	23.3	160	63.0	29.2	HII
2340160	HDS 5	11.6	8.0	40.0	15.0	29.6	HII
2350550	HDS 5	3.0	2.4	8.7	17.0		L
2350570	HDS 4	2.1	2.7	5.9	11.0	1.2	L
2370020	CS 4.5	7.9	2.8	3.3	9.5	0.9	L
2400110	HDS 4.8	12.0	0.9	16.6	18.5	1.9	L
2850080	HDS 4	14.6	4.2	9.0	17.0	1.1	L
2860820	HDS 5	8.0	0.9	27.0	11.0	14.6	HII
2880260	HDS 5	19.0	1.0	49.0	32.0	6.6	L
2960380	CS 4	7.2	1.7	26.0	10.0	16.5	HII
3050140	CS 5	1.8	0.4	6.7	3.8	8.7	HII
3500140	CS 6	8.7	2.6	33.0	14.0	13.3	HII
3550300	CS 4	12.2	2.6	22.2	18.0	3.7	L
3570190	HDS 5	13.4	8.4	50.0	22.0	14.9	HII
4060330	HDS 6	43.0	21.0	180	66.0	27.4	HII
4070140	CS 5	53.2	51.0	190	58.0	40.6	HII
4190030	CS 4	5.1	1.6	22.0	7.8	24.2	HII
4200030	CS 5	15.2	4.7	48.0	18.0	13.3	HII
4710200	CS 4.5	24.3	6.5	98.0	47.0	10.3	HII
4780060	CS 4	23.1	6.0	63.0	26.0	13.7	HII
4820430	CS 4	6.9	2.6	17.0	9.4	6.7	HII
5320090	CS 5	16.8	7.3	51.0	21.0	13.4	HII
5390050	CS 5	16.7	9.2	64.0	28.0	20.0	HII
5450100	HDS 5	23.4	24.7	95.0	26.0	30.0	HII
5480310	HDS 3	16.0	1.0	53.0	35.0	4.2	L
5480380	HDS 6	5.6	1.4	24.0	9.6	28.8	HII
6010040	CS 4.6	8.6	1.0	30.0	14.0	6.6	HII

Column 2: $\rm CS=control$ sample, $\rm HDS=high$ density sample; morphological types are: $\rm 1=Sa$ , $\rm 2=Sa$ -b, $\rm 3=Sb$ , $\rm 4=Sb$ -c, $\rm 5=S$ ..., $\rm 6=Sc$ , $\rm Sc$ -d, $\rm 7=S$ ../Irr, 8=Sd. Column 8: $\rm HII=activity$ typical of HII regions, $\rm L=activity$ typical of LINERs.
$^{\dagger}$ Only EW(H $\alpha$ ) is corrected for internal reddening.

Long-slit spectra were obtained with the Boller & Chivens Cassegrain spectrograph at the ESO 1.52 m telescope (La Silla) during several runs in 1997 and 1998 as part of a key project during Brazilian time. We used the Loral/Lesser CCD (No. 39) with $2048 \times 2048$ pixels ( $\rm 1~pixel = 15~\mu$ m) and grating No. 27 which has 600 lines mm^-1 and gives a spectral coverage of 3600-7500 Å and dispersion of 1.7 Å pix^-1. The slit width was 3'' and positioned along the major axis of the galaxies which corresponds to galactic sizes of 250 pc for the closest galaxy in the sample and to 1 kpc for the most distant galaxy in the sample.

Spectrophotometric standard stars were observed close to zenith several times during the night with a slit width of 5''. A He-Ar lamp was observed after every exposure and used for wavelength calibration. Typical exposure times were $2 \times 20{-}30$ min for galaxies and 5-10 min for stars.

Standard data reduction, including bias and flat-field correction, was performed using IRAF. One dimensional spectra were extracted from each galaxy integrated along the slit length. We corrected for Galactic extinction using the Cardelli et al. (1989) extinction curve and E(B-V) from NED. All spectra are flux calibrated and corrected for Doppler shift which was calculated using a cross-correlation technique.

Starlight subtraction was particularly critical in weak lines such as H $\beta$ . The starlight contribution was removed using the technique of McCall et al. (1985, see also Storchi-Bergmann et al. 1994). Taking into account that in the typical stellar population the equivalent width of H $\beta$ in absorption is of the order of 1.5 Å, we corrected for this effect by adding a factor of 1.5 times the continuum flux around H $\beta$ to the emission line flux. When no emission line was clearly visible we adopted a theoretical ratio, H $\alpha$ /H $\beta=2.86$ (Ho et al. 1997). In this case, the value of H $\beta$ is an upper limit. Therefore, higher ratios of H $\alpha$ /H $\beta$ can also be expected. We have investigated whether a higher ratio would influence our results by adopting ratios typical of AGNs (H $\alpha$ /H $\beta=3.1$ ). We found no significant difference given the uncertainties in the continuum determination.

We tested a second method of starlight subtraction using templates of old stellar populations from Bica (1988). We subtracted our spectra from the templates and then measured the fluxes. Both methods gave similar results given the accuracy of the measurements, dominated by the uncertainty in the continuum determination (Cid Fernandes et al. 1998).

We measured the integrated fluxes and equivalent widths of the emission lines H $\beta$ , [OIII] $\lambda$ 5007, [NII] $\lambda$ 6548, H $\alpha$ , [NII] $\lambda$ 6583, [SII] $\lambda$ 6716,6731 for 35 galaxies with good signal-to-noise spectra. Internal reddening was estimated from the Cardelli et al. (1989) extinction curve and H $\alpha$ /H $\beta$ ratios. H $\alpha$ equivalent width was measured after internal reddening correction, following the same procedure as in Ho et al. (1997).

The type of activity was classified by measuring line-intensity ratios (log([OIII] $\lambda$ 5007/H $\beta$ ) and log([NII] $\lambda$ 6583/H $\alpha$ )) and applying standard diagnostic diagrams (Baldwin et al. 1981; Veilleux & Osterbrock 1987). In Paper II we show the diagnostic diagram used to classify the type of activity.

Table 2 lists the emission line parameters as follows. Column 1: designation in the ESO-Uppsala catalog (LV89); Col. 2: type of sample (control $\rm sample=CS$ and high density $\rm sample=HDS$ ) and morphological type (LV89) $\rm 1=Sa$ , $\rm 2=Sa$ -b, $\rm 3=Sb$ , $\rm 4=Sb$ -c, $\rm 5=S$ ..., $\rm 6=Sc$ , Sc-d, $\rm 7=S$ ../Irr, $\rm 8=Sd$ ; Col. 3: H $\beta$ flux; Col. 4: [OIII] $\lambda$ 5007 flux; Col. 5: H $\alpha$ flux; Col. 6: [NII] $\lambda$ 6583 flux; Col. 7: H $\alpha$ equivalent width in Å, and Col. 8: type of activity ( $\rm L=LINERS$ , $\rm HII=HII$ region).

In Appendix A (only available in electronic form) we show the optical spectra of 35 galaxies of our sample. We also included in the Appendix the CO spectra described below and images from The Digitized Sky Surveys which allows direct inspection of the galaxies morphology.

**Table 3:** CO data.
ESO-LV	Sample &	$V_{\rm CO}$	$\Delta V_{\rm CO}$	log $L_{\rm B}$	$L_{\rm FIR}$ $\times$ 10⁹	$I_{\rm CO(1-0)}$	$M_{\rm H_2}$ $\times$ 10⁹	$I_{\rm CO(2-1)}$
name	Morph.	kms^-1	kms^-1	$L_{\odot}$	$L_{\odot}$	K kms^-1	$M_{\odot}$	K kms^-1
(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)
0310050	CS 3.5	4714	287	10.11	13.60 $\pm$ 0.39	3.62 $\pm$ 0.26	3.30 $\pm$ 0.23	3.64 $\pm$ 0.22
1060120	CS 6	4154	180	9.97	6.90 $\pm$ 0.39	2.75 $\pm$ 0.28	1.93 $\pm$ 0.19
1080130	HDS 3.5	2941	135	9.78	2.67 $\pm$ 0.15	2.43 $\pm$ 0.21	0.81 $\pm$ 0.07
1080200	CS 3.9	1720	183	9.37	4.45 $\pm$ 0.20	6.28 $\pm$ 0.25	0.65 $\pm$ 0.03	3.63 $\pm$ 0.18
1190060	HDS 7.5	1256	43	9.48	1.66 $\pm$ 0.05	1.99 $\pm$ 0.14	0.11 $\pm$ 0.01
1190190	HDS 5	1527	33	9.94	2.52 $\pm$ 0.07	5.06 $\pm$ 0.19	0.42 $\pm$ 0.02
1420500	CS 5	2135	165	10.10	4.40 $\pm$ 0.09	3.40 $\pm$ 0.25	0.59 $\pm$ 0.04
1460090	CS 5	1652	183	10.13	10.40 $\pm$ 0.34	11.68 $\pm$ 0.66	1.10 $\pm$ 0.06
1570050	HDS 5.5	1311	40	9.30	0.39 $\pm$ 0.02	1.66 $\pm$ 0.06	0.10 $\pm$ 0.01	0.88 $\pm$ 0.09
1890070	CS 4.0	3006	169	10.44	9.15 $\pm$ 0.36	4.22 $\pm$ 0.26	1.48 $\pm$ 0.09
2010220	CS 5	3990	188	9.70	3.53 $\pm$ 0.23	1.50 $\pm$ 0.11	0.98 $\pm$ 0.07	1.30 $\pm$ 0.11
2030180	CS 4	4123	157	10.27	25.39 $\pm$ 1.17	4.66 $\pm$ 0.23	3.30 $\pm$ 0.16	5.04 $\pm$ 0.14
2340160	HDS 5	5218	10	10.01	3.72 $\pm$ 0.50	0.82 $\pm$ 0.05	0.94 $\pm$ 0.06	0.45 $\pm$ 0.12
2350550	HDS 5	5098	70	10.73	9.92 $\pm$ 1.11	1.88 $\pm$ 0.11	2.04 $\pm$ 0.12	1.34 $\pm$ 0.11
2350570	HDS 4	5069	248	10.03	11.08 $\pm$ 1.30	3.22 $\pm$ 0.12	3.45 $\pm$ 0.13	3.56 $\pm$ 0.22
2370020	CS 4.5	5214	236	10.58	13.72 $\pm$ 0.70	4.42 $\pm$ 0.16	4.90 $\pm$ 0.18	1.96 $\pm$ 0.11
2400110	HDS 4.8	2890	278	10.00	5.81 $\pm$ 0.31	5.20 $\pm$ 0.17	1.65 $\pm$ 0.05
2400130	HDS 3	3284	50	9.80	5.17 $\pm$ 0.31	2.58 $\pm$ 0.15	1.08 $\pm$ 0.06
2850080	HDS 4	2838	132	10.63	4.45 $\pm$ 0.23	1.97 $\pm$ 0.21	0.64 $\pm$ 0.07
2860820	HDS 5	4958	134	9.98	4.42 $\pm$ 0.51	1.62 $\pm$ 0.09	1.66 $\pm$ 0.09	1.68 $\pm$ 0.08
2880260	HDS 5	2383	80	9.79	1.42 $\pm$ 0.10	1.51 $\pm$ 0.11	0.32 $\pm$ 0.02
2960380	CS 4	3645	51	9.90	3.73 $\pm$ 0.33	0.84 $\pm$ 0.12	0.44 $\pm$ 0.06
3050140	CS 5	4761	450	10.11	4.31 $\pm$ 0.55	2.38 $\pm$ 0.10	2.31 $\pm$ 0.10	1.21 $\pm$ 0.08
3470340	HDS 3	1671	117	9.92	7.85 $\pm$ 0.79	23.46 $^{\dagger}$ $\pm$ 0.62	2.27 $\pm$ 0.06
3500140	CS 6	3400	35	10.09	3.30 $\pm$ 0.25	2.68 $\pm$ 0.09	1.23 $\pm$ 0.04
3520530	HDS 3	3874	260	10.27	21.89 $\pm$ 0.93	10.85 $\pm$ 0.52	6.55 $\pm$ 0.32
3550260	CS 4	1985	105	9.42	0.95 $\pm$ 0.07	1.02 $\pm$ 0.13	0.15 $\pm$ 0.02
3550300	CS 4	4448	336	10.25	10.05 $\pm$ 0.43	4.08 $\pm$ 0.44	3.33 $\pm$ 0.36
3570190	HDS 5	1789	66	9.83	1.52 $\pm$ 0.06	3.40 $\pm$ 0.28	0.41 $\pm$ 0.03
4050180	CS 1	3375	124	10.27	10.67 $\pm$ 0.68	7.70 $\pm$ 0.37	3.52 $\pm$ 0.17
4060250	HDS 5	1470	83	9.98	4.42 $\pm$ 0.20	27.44 $^\ddagger$ $\pm$ 0.74	2.04 $\pm$ 0.05
4060330	HDS 6	1922	110	9.71	5.01 $\pm$ 0.21	3.15 $\pm$ 0.17	0.42 $\pm$ 0.02
4070140	CS 5	2761	129	9.85	3.54 $\pm$ 0.23	2.64 $\pm$ 0.14	0.78 $\pm$ 0.04
4190030	CS 4	4146	83	10.20	11.19 $\pm$ 0.36	1.52 $\pm$ 0.13	1.10 $\pm$ 0.09
4200030	CS 5	4093	163	10.22	6.41 $\pm$ 0.41	2.86 $\pm$ 0.20	2.02 $\pm$ 0.14
4710200	CS 4.5	3017	160	10.30	12.49 $\pm$ 0.53	5.46 $\pm$ 0.36	1.95 $\pm$ 0.13
4780060	CS 4	5401	164	10.58	51.12 $\pm$ 2.91	8.79 $\pm$ 0.37	10.86 $\pm$ 0.46	15.16 $\pm$ 0.33
4820430	CS 4	4073	85	10.17	6.57 $\pm$ 0.33	3.36 $\pm$ 0.30	2.35 $\pm$ 0.21
4840250	CS 2	4128	191	10.13	16.54 $\pm$ 0.64	3.63 $\pm$ 0.31	2.65 $\pm$ 0.22
5320090	CS 5	2582	83	9.91	4.22 $\pm$ 0.20	1.54 $\pm$ 0.17	0.41 $\pm$ 0.05
5390050	CS 5	3158	256	9.98	5.03 $\pm$ 0.29	4.95 $\pm$ 0.33	1.99 $\pm$ 0.13
5450100	HDS 5	1715	21	9.55	3.21 $\pm$ 0.14	1.29 $\pm$ 0.09	0.15 $\pm$ 0.01	2.67 $\pm$ 0.13
5450110	HDS 5	1456	168	10.35	14.78 $\pm$ 0.72	27.01 $\pm$ 0.92	2.15 $\pm$ 0.07
5480070	HDS 3.5	1557	17	9.87	1.05 $\pm$ 0.05	1.79 $\pm$ 0.11	0.17 $\pm$ 0.01
5480310	HDS 3	1531	108	9.79	3.17 $\pm$ 0.13	6.99 $\pm$ 0.32	0.65 $\pm$ 0.03
5480380	HDS 6	1874	86	10.03	10.56 $\pm$ 0.31	2.14 $\pm$ 0.15	0.30 $\pm$ 0.02
6010040	CS 4.6	5219	103	10.01	3.85 $\pm$ 0.56	1.01 $\pm$ 0.08	1.17 $\pm$ 0.09	0.78 $\pm$ 0.04

$^{\dagger}$ added CO(1-0) intensities of 5 points (map);
$^\ddagger$ added CO(1-0) intenstities of 7 points (map).
Column 2: CS=control sample, $\rm HDS=high$ density sample; morphological types are: $\rm 1=Sa$ ,
$\rm 2=Sa$ -b, $\rm 3=Sb$ , $\rm 4=Sb$ -c, $\rm 5=S$ ..., $\rm 6=Sc$ , Sc-d, $\rm 7=S$ ../Irr, $\rm 8=Sd$ .

3 The optical data