A total of 31 hours of the ISO mission was dedicated to ISOPHOT pointed observations of statistical samples of local universe galaxies. All these projects were complementary in terms of selection and observational goals. In descending order of depth, the published surveys are: the ISOPHOT Virgo Cluster Deep Survey (63 galaxies), the Coma/A1367 Survey (18 galaxies) and the ISO Bright Spiral Galaxies Survey (77 galaxies). In addition, 115 galaxies have been catalogued from the Serendipity Survey. Furthermore, the statistical sample of 60 bright galaxies studied spectroscopically by LWS by Malhotra et al. (2001) was also observed by ISOPHOT at 170µm with short stares, but the photometry is not yet published.
The ISOPHOT Virgo Cluster Deep Survey (Tuffs et al. 2002; Popescu et al. 2002) represents the deepest survey (both in luminosity and surface brightness terms) of normal galaxies yet measured in the FIR. A complete volume- and luminosity sample of 63 gas-rich Virgo Cluster galaxies selected from the Virgo Cluster Catalog (Binggeli, Sandage & Tammann 1985; see also Binggeli, Popescu & Tammann 1993) with Hubble types later than S0 and brighter than BT 16.8 were measured with ISOPHOT at 60, 100 and 170µm. Deep oversampled P32 strip maps covered the entire optical extent of each target (down to the 25.5magarcsec-2 B-band isophote) as well as adjacent background directions. The faintest detected emissions from the survey are 50, 40 and 80mJy at 60, 100 and 170µm, respectively. The total on target time (ISOPHOT) for the survey was 20 hours. The sample was also mapped by ISOCAM (Boselli et al. 1997) and was (in part) observed by LWS (Leech et al. 1999).
The ISOPHOT Virgo Cluster Deep Survey is providing the basis for statistical investigations of the FIR spectral energy distributions of gas rich galaxies in the local universe spanning a broad range in star-formation activity and morphological types, including dwarf systems and galaxies with rather quiescent star formation activity.
The Coma/A1367 Survey (Contursi et al. 2001) consists of 6 spiral and 12 irregular galaxies having IRAS detections at 60 µm. The galaxies were selected to be located within 2 or 1 degrees of the X-ray centres of Coma and A1367 clusters, respectively, with emphasis on peculiar optical morphologies. Each galaxy was observed in a single pointing, by chopping between the galaxy and a background direction. The data were taken at 60, 80, 100, 120, 170 and 200 µm (but only reduced for 120, 170 and 200 µm) for a total on target time (ISOPHOT) of 2hr. The sample, also observed with ISOCAM, provided a database of integrated flux densities for a pure cluster sample of high luminosity spiral and irregular galaxies.
The ISO Bright Spiral Galaxies Survey (Bendo et al. 2002a) consists of 77 spiral and S0 galaxies chosen from the Revised Shapley-Ames Catalog (RSA), with BT 12.0. Almost all are IRAS sources. Mainly an ISOCAM survey, the project also used 7hr of on target ISOPHOT time to take 60, 100 and 170 µm short stares towards the nucleus of the galaxies and towards background fields. The sample provides a database of FIR surface brightnesses of the central regions of bright spiral galaxies, including S0s.
The ISO Bright Spiral Galaxies Survey and the ISO-PHOT Virgo Cluster Deep Survey represent the principle investigations of optical selected samples of normal galaxies. It should be emphasised that the main difference between them is primarily one of shallow versus deep, rather than field versus cluster, since by design the Virgo Sample predominantly consists of infalling galaxies from the field, and no cluster specific effects could be found.
The Serendipity Survey (Stickel et al. 2000) has so far catalogued 115 galaxies with S 2Jy at 170 µm and with morphological types predominantly S0/a-Scd. This sample provides a database of integrated 170 µm flux densities for relatively high luminosity spiral galaxies, all detected by IRAS at 60 & 100 µm. A more detailed description of this survey was given in the presentation of Stickel.