The redshift survey compiled by Strauss et al. (1992), from which we have
extracted our sample of ultraluminous infrared galaxies,
includes objects from the IRAS Point Source Catalog with a 60 m\
flux greater than 1.936 Jy. A flux color constraint was also applied by these authors to exclude
stars and galactic sources (f602 > f12f25). From
the 2658 galaxies of the original sample, we have selected the most luminous
objects in the far infrared according to the following criteria:
The choice of the southern hemisphere was motivated by the desire to cover a region of the sky not
present in the ULIRG sample of
Sanders et al. (1988a).
The second
constraint excludes galaxies contaminated by the galactic plane.
was calculated using the formula:
which is an approximation of the luminosity (Lonsdale et al. 1985),
and assuming
. A value of
is comparable to the canonical limit
, originally used in
ULIRG studies, where
is an approximation of the
luminosity, given by
Perault (1989), as:
was preferentially chosen instead of
because the 1.9 Jy survey
includes fluxes from the Point Source Catalog (PSC),
which has a low sensitivity in the mid-infrared bands, 12
m and
25
m, used in the determination of
.
With all the criteria above-mentioned,
we found the 24 galaxies listed in Table 1 (click here). The optical positions
in Cols. 2-3 are given by
Strauss et al. (1992); the redshifts in Col. 4 have been calculated from our
spectrophotometric data, when available.
For systems made of close merging disks, the mean redshift is indicated,
whereas in loose interacting systems, the quoted redshift is that of
the nearest galaxy from the IRAS position.
The mid and far infrared fluxes from the IRAS Faint Source Catalog (FSC)
version 2, more sensitive than the PSC initially used by
Strauss et al. (1992),
are given in Cols. 5-8. The infrared, , and far-infrared luminosities,
, have been recalculated with our new redshifts and with the
FSC fluxes (Cols. 9-10). Figure 1 (click here) and Fig. 2
present the redshift and luminosity distributions. Redshifts, z, range
between 0.04 and 0.13;
with our selection criteria, the SULIRG sample is complete up to z=0.1.
The most luminous object is IRAS 20100-4156, with
.
IRAS name | RA | DEC | z | FSC flux densities (Jy) | ![]() | ![]() | |||
B1950 | B1950 | 12 ![]() | 25 ![]() | 60 ![]() |
100 ![]() | ||||
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
00199-7426 | 00 19 56.4 | -74 26 10 | 0.0963 | 0.11 | 0.33 | 4.16 | 6.42 | 12.02 | 12.08 |
05189-2524 | 05 18 58.6 | -25 24 39 | 0.0427 | 0.73 | 3.44 | 13.67 | 11.36 | 11.82 | 12.02 |
06035-7102 | 06 03 34.6 | -71 02 58 | 0.0794 | 0.12 | 0.57 | 5.13 | 5.65 | 11.91 | 12.00 |
06206-6315 | 06 20 40.3 | -63 15 51 | 0.0920 | 0.07 | 0.29 | 3.96 | 4.58 | 11.92 | 11.98 |
09061-1248 | 09 06 11.7 | -12 48 48 | 0.0738 | 0.12 | 0.19 | 3.63 | 5.32 | 11.75 | 11.81 |
09111-1007 | 09 11 11.1 | -10 07 01 | 0.0537 | 0.17 | 0.47 | 7.08 | 11.06 | 11.80 | 11.86 |
11095-0238 | 11 09 30.2 | -02 38 01 | 0.1065 | 0.13 | 0.42 | 3.25 | 2.53 | 11.89 | 12.02 |
14348-1447 | 14 34 52.3 | -14 47 24 | 0.0823 | 0.14 | 0.49 | 6.87 | 7.07 | 12.06 | 12.13 |
14378-3651 | 14 37 53.4 | -36 51 43 | 0.0682 | 0.12 | 0.52 | 6.19 | 6.34 | 11.87 | 11.94 |
15462-0450 | 15 46 17.6 | -04 50 26 | 0.0998 | 0.13 | 0.45 | 2.92 | 3.00 | 11.83 | 11.97 |
16090-0139 | 16 09 04.3 | -01 39 27 | 0.1334 | 0.09 | 0.26 | 3.61 | 4.87 | 12.17 | 12.23 |
17208-0014 | 17 20 48.2 | -00 14 17 | 0.0429 | 0.20 | 1.66 | 31.14 | 34.90 | 12.22 | 12.25 |
19254-7245 | 19 25 27.8 | -72 45 39 | 0.0617 | 0.22 | 1.24 | 5.48 | 5.79 | 11.74 | 11.91 |
20046-0623 | 20 04 39.2 | -06 23 10 | 0.0845 | 0.09 | 0.22 | 3.23 | 3.91 | 11.77 | 11.85 |
20087-0308 | 20 08 46.4 | -03 08 52 | 0.1055 | 0.13 | 0.24 | 4.70 | 6.54 | 12.12 | 12.18 |
20100-4156 | 20 10 05.8 | -41 56 39 | 0.1298 | 0.13 | 0.34 | 5.23 | 5.16 | 12.27 | 12.34 |
20414-1651 | 20 41 28.3 | -16 51 12 | 0.0870 | 0.65 | 0.35 | 4.36 | 5.25 | 11.92 | 12.14 |
20551-4250 | 20 55 09.3 | -42 50 37 | 0.0426 | 0.28 | 1.91 | 12.78 | 9.95 | 11.78 | 11.90 |
21130-4446 | 21 13 00.5 | -44 46 14 | 0.0929 | 0.07 | 0.16 | 3.11 | 3.78 | 11.83 | 11.88 |
21504-0628 | 21 50 28.4 | -06 28 55 | 0.0775 | 0.09 | 0.39 | 3.48 | 2.89 | 11.69 | 11.80 |
22491-1808 | 22 49 09.5 | -18 08 18 | 0.0777 | 0.12 | 0.55 | 5.44 | 4.45 | 11.89 | 11.98 |
23128-5919 | 23 12 50.6 | -59 19 37 | 0.0445 | 0.24 | 1.59 | 10.80 | 10.99 | 11.77 | 11.88 |
23230-6926 | 23 23 02.5 | -69 26 47 | 0.1063 | 0.06 | 0.29 | 3.74 | 3.42 | 11.97 | 12.04 |
23389-6139 | 23 38 59.4 | -61 39 28 | 0.0932 | 0.06 | 0.24 | 3.63 | 4.26 | 11.89 | 11.95 |
Figure 1: Redshift distribution of SURILGs
Figure 2: Infrared (dotted) and far infrared (plain) luminosity distributions of SURILGs
The SULIRG sample includes the list of ULIRGs compiled by
Melnick & Mirabel (1990). The more northern objects are also
present in
the catalog of Murphy et al. (1996) (however these authors present only
imaging data); three galaxies belong
to the IRAS Bright Galaxy Sample (Soifer et al.
1987) and are therefore in common with the ULIRG sample of
Sanders et al. (1988a).
Some of the nearest objects have already been studied in details:
IRAS 14348-1447 (Sanders et al. 1988c),
IRAS 19254-7245
("The Super-Antennae'', Mirabel et al. 1991;
Colina et al. 1991),
IRAS 20551-4251 (Johansson 1991) and IRAS 23128-5919
(Bergvall & Johansson1985). Moreover
Mirabel et al. (1988) have
published CO measurements for 15 galaxies.
One object, IRAS 17208-0014,
is known as an OH megamaser (Martin et al. 1989).
We have obtained optical CCD images for all the galaxies in our sample, but IRAS 05189-2524, one of the BGS members, and optical spectra for 18 of them; 17 galaxies have also been imaged in the near infrared.