2. Observations

The observations have been performed with the transit-meridian Nançay (France) radiotelescope, which has a collecting area of ().

The half-power beam width at 21-cm is 3.6 arcmin (EW) arcmin (NS) (at zero declination). The minimal system temperature at is about 37 K in both horizontal and vertical polarizations. The gain of the antenna has been calibrated according to Fouqué et al. (1990).

The spectrometer is a 1024-channels autocorrelator of 6.4 MHz total bandwidth. The spacing of the channels corresponds to at 21 cm with a bank of 512 channels in each polarization (horizontal and vertical). After boxcar smoothing the final resolution is typically . Each final spectrum corresponds to the integration on n cycles of 4 minutes each (on/off beam switch mode, the size of the beam, and the position of the comparison field varying with declination). After rejection of disturbed cycles (interferences, noisy baseline), the spectrum is straightened by fitting a polynomial function to the external parts of the line (1st to 6th degree), and the maximum intensity of the line is estimated.

Observed radial velocities correspond to the median point of the 21-cm line profile measured at 20% level of maximum intensity. The internal mean error on V₂₀ is calculated according to Fouqué et al. (1990) from the actual spectral resolution r, the slope a=(W₂₀+W₅₀)/2 of the line profile, and the signal to noise ratio S/N:

Line widths are measured on the observed profile at two standard levels corresponding to 20% and 50% of the maximum intensity of the line. These widths W₂₀ and W₅₀ are first corrected for spectral resolution effect in agreement with Bottinelli et al. (1990), and further corrected for internal velocity dispersion assuming an isotropic distribution of the non-circular motions and a nearly gaussian velocity distribution (Fouqué et al. 1990):

where (, k(20)=1.96 and k(50)=1.13), and w is equal to 120 and for the levels 20% and 50% respectively.

The mean errors are respectively and for the 20% and 50% widths, according to Fouqué et al. (1990).

Integrated HI fluxes are expressed in and corrected for beam-filling, when both photometric diameter and axis ratios were known, using the formula given by Bottinelli et al. (1990):

where

and is the position angle of the galaxy defined north-eastwards, D₂₅ and d₂₅ are the photometric major and minor axis respectively.

These fluxes have been calibrated by using a set of 6 close calibrator galaxies, whose HI-fluxes were accurately measured by Fouqué (1982) and which have been regularly observed during all the period covered by our survey (june 96 - November 96). This calibration is done by monitoring the performance of the Nançay system with time, in both horizontal and vertical polarization separately, in order to get for each observation the better HI flux measurement (see Theureau et al. 1997 for more details).

Main optical parameters of observed galaxies are given in Table 1. When more than one measurement of optical radial velocity is available from literature we list its value extracted from the Lyon-Meudon Extragalactic Database (LEDA, Paturel et al. 1997) whereas in last column all references on radial velocity measurements for each galaxy are given.

Note that all astrophysical data extracted from LEDA are reduced to a common system according to well defined reduction formulae leading to mean homogenized parameters. Apparent diameters are reduced to the standard system of the isophote at the brightness of 25 B-mag . Apparent B-magnitudes are reduced to the RC3 system. Both are corrected for extinction, inclination (i.e. opacity), and redshift effect. For extinction correction on B-magnitude, or diameters, the RC2 system has been used. Opacity corrections in B-band are calculated according to Bottinelli et al. (1995).

  
Figure 1: Comparison of optical heliocentric radial velocities (values from LEDA, see Table 1) with our HI velocity measurements with the Nançay radiotelescope (in ): the dashed line corresponds to

The observed 21-cm line profiles are given in Fig. 2 (click here). All derived HI parameters, corrected to the optical velocity scale, are listed in Table 2 (click here). Our 21-cm radial velocities appear in very good agreement with optical ones as shown in Fig. 1 (click here), where the line corresponding to is drawn. The values of the rms noise, averaged outside the line profile indicate a mean rms noise of about 2 mJy at resolution . Discussions of parameters and their detailed comparison with those from other similar lists of galaxies will be presented in a forthcoming paper.

    
Figure 2: HI spectra for 39 Kazarian galaxies: HI flux density in mJy is plotted against radial velocity in expressed in terms of optical redshift

 

Kaz.name V₂₀ rms W₂₀ rms W₅₀ rms rms rms S/N Notes

km s^-1 km s^-1 km s^-1 Jy km s^-1 Jy km s^-1 mJy

KAZ001 3589 7 313 20 254 13 2.242 .003 11.7 11.9 1.2 12.1 4.6

KAZ003 6308 5 147 16 137 11 2.207 .117 2.9 2.9 .5 7.4 2.0

KAZ016 6603 8 262 25 246 16 2.049 .002 3.1 3.2 .6 5.6 2.3 c

KAZ018 4777 16 372 47 313 31 2.242 .004 4.0 4.1 .7 5.1 2.2

KAZ019 4770 4 394 13 377 8 2.287 .000 9.5 9.9 .8 11.2 2.1

KAZ023 6796 13 469 39 392 26 2.307 .002 6.2 6.6 1.1 6.9 4.3

KAZ024 6286 10 405 30 388 20 2.300 .001 4.2 4.3 .7 4.8 2.0

KAZ026 4031 14 282 43 170 29 2.166 .012 3.1 3.1 .6 7.5 2.6

KAZ039 8025 15 224 44 209 29 1.4 .6 3.1 2.3

KAZ047 4640 16 578 48 573 32 1.2 .6 2.0 1.8

KAZ052 3910 14 170 41 166 27 1.5 1.5 .9 2.2 3.7

KAZ063 6519 23 472 70 443 47 3.7 1.4 2.5 4.1

KAZ065 7745 10 218 30 185 20 2.020 .006 6.2 6.3 1.2 6.2 4.3

KAZ069 1000 23 469 69 427 46 3.4 3.5 .9 3.0 2.4

KAZ098 4503 16 377 47 353 31 3.9 1.1 3.4 3.2

KAZ120 4866 38 528 115 491 77 2.454 .010 5.8 5.9 2.8 1.7 7.5

KAZ198 4393 25 560 76 448 50 2.380 .004 3.5 3.7 1.0 4.3 3.6 c

KAZ201 1505 8 318 25 314 17 3.1 1.0 3.6 3.7

KAZ211 1680 37 566 112 394 74 6.5 1.6 3.6 4.4

KAZ216 7620 27 284 80 191 53 2.2 .7 3.7 2.6

KAZ228 9777 20 541 59 513 39 1.3 1.3 .4 2.9 .9

KAZ282 3685 18 330 53 281 35 2.231 .007 2.8 2.8 .8 4.2 2.7

KAZ347 4286 21 536 62 282 41 6.9 7.0 .7 7.8 2.0 c

KAZ445 4870 25 335 75 235 50 2.257 .018 4.1 4.3 1.5 4.1 6.7

KAZ512 15021 10 540 29 540 20 1.2 .4 2.3 1.1

KAZ524 8529 18 294 54 242 36 2.242 .010 1.5 1.5 .4 4.2 1.2 c

KAZ544 9832 14 307 41 243 27 2.274 .006 2.6 2.6 .4 6.1 1.2

KAZ546 7495 5 296 15 281 10 2.174 .001 5.3 5.4 .6 9.3 1.8

KAZ566 12479 7 608 21 609 14 2.483 .000 4.4 4.5 1.0 3.2 2.2

KAZ579 7099 8 113 23 73 16 2.2 2.3 .4 8.6 2.1

Column 1: Number from Kazarian lists.
Column 2: Heliocentric systemic radial velocity measured at the mid-point of the 20% level of peak intensity and its mean error.
Column 3: Line width measured at 20% of the maximum intensity (corrected for resolution and internal motions) with its corresponding mean error.
Column 4: Line width measured at 50% of the maximum intensity (corrected for resolution and internal motions) with its corresponding mean error.
Column 5: Estimated maximum of rotational velocity calculated according to Paturel et al. (1997) for spiral galaxies with known inclination angle and corresponding mean error.
Column 6: Measured HI flux (in Jy km/s), calibrated according to our set of calibrators (see text).
Column 7: Corrected HI flux (in Jy km/s).
Column 8: Mean error of HI flux.
Column 9: Signal-to-Noise ratio.
Column 10: rms noise outside the line profile (in mJy).
Column 11: HI-confused galaxies are marked with a c.