\begin{table}%t6 - NON ! %ta.2 !
\setlength\tabcolsep{4pt}
  \caption{\label{abempirica2}Results of the oxygen abundance, in the form $\abox$, for objects with a direct estimation of the metallicity, considering 
several empirical calibrations.}
{\begin{tabular}{l@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}}  c@{\hspace{2pt}} 
c@{\hspace{2pt}} c@{\hspace{2pt}}  c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} 
c@{\hspace{2pt}} c@{\hspace{2pt}} c@{\hspace{2pt}} c } %c}
  \hline\hline
   \noalign{\smallskip}
Region & Branch &  \Te & EP84 &  MRS85 & M91 & ZKH94 & P00 & P01\tablefootmark{a}&PT05\tablefootmark{b}& KD02 & KK04 & D02 & PP04a & PP04b & PP04c & N06a\tablefootmark{c}& N06b & N06c \\ 
% & Izotov06\\ 
& & &  R$_{23}$ & R$_{23}$ & R$_{23}$, $y$ & R$_{23}$ & R$_{23}$ & R$_{23}$, P & R$_{23}$, P & R$_{23}$, $q$ & R$_{23}$, $q$ & 
N$_2$ & N$_2$ & N$_2$ & O$_3$N$_2$ & R$_{23}$ & N$_2$ & O$_3$N$_2$  \\   
  \hline
HCG 31 AC   &   H  &   $8.22 \pm 0.05$ &   8.25  &    8.89    &    8.67   &    8.74    &    8.47   &    8.15   &    8.09   &    7.99   &    8.12   &    8.40   &    8.34   &    8.29   &    8.30   &    8.05    &   8.16  &    8.22\\ %   &    8.34\\ 
HCG 31 B    &   H  &   $8.14 \pm 0.08$ &   8.14  &    8.48    &    8.29   &    8.44    &    8.24   &    8.22   &    8.12   &    8.41   &    8.44   &    8.39   &    8.33   &    8.28   &    8.29   &    8.07    &   8.16  &    8.20\\ %   &    8.21\\  
HCG 31 E    &   H  &   $8.13 \pm 0.09$ &   8.17  &    8.62    &    8.14   &    8.53    &    8.31   &    8.18   &    8.13   &    8.19   &    8.32   &    8.35   &    8.30   &    8.26   &    8.25   &    8.07    &   8.11  &    8.15\\ %   &    8.16\\  
HCG 31 F1   &   L  &   $8.07 \pm 0.06$ &   8.02  &    8.30    &    8.13   &   \nodata  &    7.86   &    8.12   &    7.99   &    8.46   &    8.33   &    8.05   &    8.07   &    8.09   &    8.03   &   \nodata  &   7.81  &    7.67\\ %   &    8.10\\  
HCG 31 F2   &   L  &   $8.03 \pm 0.10$ &   7.90  &    8.54    &    8.06   &    8.48    &    7.76   &    8.13   &    7.95   &    8.19   &    8.27   &    8.06   &    8.07   &    8.10   &    8.07   &    8.07    &   7.83  &    7.79\\ %   &    8.07\\  
HCG 31 G    &   H  &   $8.15 \pm 0.08$ &   8.13  &    8.43    &    8.26   &    8.40    &    8.22   &    8.11   &    8.17   &    8.31   &    8.42   &    8.41   &    8.34   &    8.29   &    8.26   &    8.07    &   8.17  &    8.16\\ %   &    8.23\\
Mkn 1199 C  &   H  &   $8.75 \pm 0.12$ &   9.37  &    9.26    &    9.00   &    9.18    &    9.19   &    8.71   &    8.54   &    9.14   &    9.14   &    8.92   &    8.74   &    8.90   &    8.81   &    9.18    &   8.78  &    8.94\\ %  &   \noda\\
Haro 15 A   &   H  &   $8.10 \pm 0.06$ &   8.08  &   \nodata  &    8.14   &   \nodata  &    7.91   &    8.12   &    8.12   &    8.48   &    8.34   &    7.98   &    8.01   &    8.05   &    7.97   &   \nodata  &   7.74  &    7.38\\ %   &    8.08\\	
Mkn 5 A1    &   L  &   $8.07 \pm 0.07$ &   7.90  &    8.54    &    8.04   &    8.48    &    7.76   &    8.13   &    8.13   &    8.19   &    8.26   &    8.18   &    8.17   &    8.16   &    8.12   &    8.07    &   7.94  &    7.89\\ %   &    8.00\\	
Mkn 5 A2    &   L  &   $8.08 \pm 0.07$ &   7.95  &    8.43    &    8.14   &    8.41    &    7.81   &    7.92   &    8.17   &    8.18   &    8.33   &    8.16   &    8.15   &    8.15   &    8.11   &    8.07    &   7.92  &    7.87\\ %   &    8.08\\
IRAS 08208+2816  &   H  &   $8.33 \pm 0.08$ &   8.15  &   8.50  &   8.55  &    8.46    &    8.25   &    8.42   &    8.35   &    8.35   &    8.25   &    8.47   &    8.39   &    8.34   &    8.23   &    8.35    &   8.23  &    8.11\\ %   &    8.34\\		
POX 4      &   L  &   $8.03 \pm 0.04$ &   8.15  &   \nodata  &    8.20   &    \nodata  &   7.97   &    7.92   &    8.06   &    8.48   &    8.40   &    7.78   &    7.86   &    7.91   &    7.87   &   \nodata  &   7.53  &   \nodata\\ %  &   8.02\\	
UM 420      &   L  &   $7.95 \pm 0.05$ &   7.78  &    8.73    &    7.98   &    8.61    &    7.66   &    7.85   &    7.86   &    8.02   &    8.16   &    8.20   &    8.39   &    8.33   &    8.28   &    7.57    &   8.15  &    8.14\\ %   &    7.95\\ 
SBS 0926+606A  &   L  &   $7.94 \pm 0.08$ &   7.88  &   8.57  &    7.97   &    8.50    &    7.75   &    7.77   &    7.80   &    8.17   &    8.20   &    7.97   &    8.00   &    8.05   &    8.02   &    7.71    &   7.73  &    7.64\\ %   &    7.94\\	
SBS 0948+532  &   L  &   $8.03 \pm 0.05$ &   8.01  &    8.31  &    8.06   &   \nodata  &    7.86   &    7.82   &    8.10   &    8.34   &    8.28   &    7.91   &    7.95   &    8.01   &    7.95   &   \nodata  &   8.01  &   \nodata\\ %  &   8.05\\	
SBS 1054+365  &   L  &   $8.00 \pm 0.07$ &   8.05  &    8.21  &    8.09   &   \nodata  &    7.89   &    7.84   &    7.91   &    8.48   &    8.30   &    7.87   &    7.93   &    7.98   &    7.93   &   \nodata  &   7.63  &   \nodata\\ %  &   8.00\\  
SBS 1211+540  &   L  &   $7.65 \pm 0.04$ &   7.86  &    8.60  &    7.85   &    8.52    &    7.73   &    7.68   &    7.65   &    8.02   &    8.10   &    7.58   &    7.70   &    7.69   &    7.84   &    7.68    &   7.31  &   \nodata\\ %  &   7.64\\  
SBS 1319+579A  &   L  &   $8.05 \pm 0.06$ &   8.09  &   \nodata  &   8.13  &   \nodata  &   7.93   &    8.11   &    8.11   &    8.48   &    8.33   &    7.77   &    7.85   &    7.90   &    7.88   &   \nodata  &   7.52  &   \nodata\\ %  &   8.05\\  
SBS 1319+579B  &   L  &   $8.12 \pm 0.10$ &   7.85  &   8.62  &    8.01   &    8.53    &    7.72   &    8.13   &    8.12   &    8.13   &    8.23   &    8.14   &    8.14   &    8.14   &    8.11   &    8.07    &   7.90  &    7.89\\ %   &    8.09\\  
SBS 1319+579 C  &   L  &   $8.15 \pm 0.07$ &   7.85  &   8.62  &   8.02   &    8.53    &    7.72   &    8.13   &    8.13   &    8.12   &    8.23   &    8.18   &    8.17   &    8.16   &    8.13   &    8.06    &   7.94  &    7.93\\ %   &    8.12\\  
SBS 1415+437 C  &   L  &   $7.58 \pm 0.05$ &   7.63  &   8.91  &   7.72   &    8.76    &    7.53   &    7.57   &    7.55   &    7.86   &    7.99   &    7.79   &    7.86   &    7.92   &    7.99   &    7.39    &   7.55  &    7.55\\ %   &    7.60\\  
SBS 1415+437 A  &   L  &   $7.61 \pm 0.06$ &   7.58  &   8.96  &   7.64   &    8.80    &    7.49   &    7.50   &    7.48   &    7.82   &    7.92   &    7.72   &    7.81   &    7.86   &    7.97   &    7.34    &   7.48  &    7.41\\ %   &    7.59\\ 
III Zw 107   &   H  &   $8.23 \pm 0.09$ &   8.17    &   8.62  &   8.57   &    8.53     &    8.31   &    8.40   &    8.35   &    8.13   &    8.24   &    8.39   &    8.33   &    8.28   &    8.23   &    8.46    &   8.15  &    8.10\\ %   &    8.22\\ 
Tol 9 INT    &   H  &   $8.58 \pm 0.15$ &   8.30  &    9.00   &    8.76   &    8.84    &    8.58   &    8.61   &    8.55   &    8.95   &    8.90   &    8.68   &    8.56   &    8.54   &    8.42   &    8.77    &   8.46  &    8.40\\ %   &    8.49\\ 
Tol 9 NOT    &   H  &   $8.55 \pm 0.16$ &   8.29  &    8.97   &    8.73   &    8.81    &    8.55   &    8.56   &    8.50   &    8.94   &    8.88   &    8.72   &    8.59   &    8.59   &    8.44   &    8.75    &   8.51  &    8.44\\ %  &   \noda\\ 
Tol 1457-262A  &   L  &   $8.05 \pm 0.07$ &   8.09  &   \nodata  &   8.26  &   \nodata  &   7.92   &    8.11   &    8.20   &    8.58   &    8.42   &    8.04   &    8.06   &    8.09   &    8.02   &   \nodata  &   7.80  &    7.63\\ %   &    8.08\\ 
Tol 1457-262B  &   L  &   $7.88 \pm 0.07$ &   8.55  &   \nodata  &   8.21  &   \nodata  &   7.87   &    7.91   &    8.21   &    8.38   &    8.29   &    7.88   &    7.93   &    7.99   &    7.96   &   \nodata  &   7.60  &   \nodata\\ %  &   7.90\\ 
Tol 1457-262C  &   L  &   $8.06 \pm 0.11$ &   8.48  &   \nodata  &   8.21  &   \nodata  &   7.88   &    8.00   &    8.24   &    8.48   &    8.37   &    8.07   &    8.08   &    8.10   &    8.06   &   \nodata  &   7.83  &    7.77\\ %   &    8.07\\ 
ESO 566-8   &   H  &   $8.46 \pm 0.11$ &   8.27  &    8.92   &    8.68   &     8.77    &    8.50   &    8.44   &    8.38   &    8.92   &    8.84   &    8.84   &    8.68   &    8.76   &    8.51   &    8.70    &   8.66  &    8.53\\ %  &   \noda\\
NGC 5253 A  &   H  &   $8.18 \pm 0.04$ &   8.09  &    8.24   &    8.13   &   \nodata   &    8.15   &    8.11   &    8.13   &    8.53   &    8.33   &    8.40   &    8.34   &    8.28   &    8.17   &   \nodata  &   8.16  &    8.00\\ %   &    8.15\\ 
NGC 5253 B  &   H  &   $8.19 \pm 0.04$ &   8.09  &    8.21   &    8.14   &   \nodata   &    8.14   &    8.11   &    8.13   &    8.48   &    8.34   &    8.34   &    8.29   &    8.25   &    8.14   &   \nodata  &   8.10  &    7.94\\ %   &    8.19\\ 
NGC 5253 C  &   L  &   $8.28 \pm 0.04$ &   8.14  &    8.46    &    8.53   &    8.42    &    8.23   &    8.38   &    8.32   &    8.67   &    8.63   &    8.11   &    8.11   &    8.13   &    8.08   &    8.30    &   7.87  &    7.80\\ %   &    8.26\\ 
NGC 5253 D  &   L  &   $8.31 \pm 0.07$ &   8.15  &    8.52    &    8.19   &    8.47    &    8.26   &    8.23   &    8.17   &    8.32   &    8.37   &    8.31   &    8.27   &    8.23   &    8.22   &    8.37    &   8.07  &    8.10\\ %   &    8.37\\     
%\noalign{\smallskip}
\hline
  \end{tabular}}
    \tablefoot{The empirical calibrations and the parameters used for each of them are:   
 EP84: Edmunds \& Pagel (\cite{Edmunds84}) that involves the $R_{23}$ parameter; MRS85: McCall et~al. (\cite{McCall85}) using
$R_{23}$; M91: McGaugh (\cite{McGaugh91}) using $R_{23}$ and $y$; ZKH94: Zaritsky et~al. (\cite{Zaritsky94}) using $R_{23}$; P00: Pilyugin (\cite{Pilyugin00}) using 
$R_{23}$; P01: Pilyugin (\cite{Pilyugin01}a,b) using $R_{23}$ and $P$; KD02: Kewley \& Dopita (\cite{Kewley02}) using $R_{23}$ and $q$; KK04: Kobulnicky \& Kewley (\cite{Kobulnicky04}) 
using $R_{23}$ and $q$; D02: Denicol\'o et~al. (\cite{Denicolo02}) using the N$_2$ parameter; PP04: Pettini \& Pagel (\cite{Pettini04}), using (a) N$_2$ with 
a linear fit, (b) N$_2$ with a cubic fit, (c) the O$_3$N$_2$ parameter; N06: Nagao et~al. (\cite{Nagao06}) using the cubic relations involving the $R_{23}$ (a), 
N$_2$ (b) and O$_3$N$_2$ (c) parameters. The value compiled in the column labeled \Te\ is the oxygen abundance derived by the direct method.}
\tablefoottext{a}{The value listed for P01 is the average value between the high- and the low-metallicity branches for objects with $7.90<\abox<8.20$.}\\
\tablefoottext{b}{The value listed for PT05 is the average value between the high- and the low-metallicity branches for objects with $8.05<\abox<8.20$.}\\
\tablefoottext{c}{The value listed for N06 is the average value between the high- and the low-metallicity branches for objects with $8.00<\abox<8.15$.} 
\end{table}