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The QDOT all-sky IRAS galaxy redshift survey
We describe the construction of the QDOT survey, which is publiclyavailable from an anonymous FTP account. The catalogue consists ofinfrared properties and redshifts of an all-sky sample of 2387 IRASgalaxies brighter than the IRAS PSC 60-μm completeness limit(S_60>0.6Jy), sparsely sampled at a rate of one-in-six. At |b|>10deg, after removing a small number of Galactic sources, the redshiftcompleteness is better than 98per cent (2086/2127). New redshifts for1401 IRAS sources were obtained to complete the catalogue; themeasurement and reduction of these are described, and the new redshiftstabulated here. We also tabulate all sources at |b|>10 deg with noredshift so far, and sources with conflicting alternative redshiftseither from our own work, or from published velocities. A list of 95ultraluminous galaxies (i.e. with L_60μm>10^12 L_solar) is alsoprovided. Of these, ~20per cent are AGN of some kind; the broad-lineobjects typically show strong Feii emission. Since the publication ofthe first QDOT papers, there have been several hundred velocity changes:some velocities are new, some QDOT velocities have been replaced by moreaccurate values, and some errors have been corrected. We also present anew analysis of the accuracy and linearity of IRAS 60-μm fluxes. Wefind that the flux uncertainties are well described by a combination of0.05-Jy fixed size uncertainty and 8per cent fractional uncertainty.This is not enough to cause the large Malmquist-type errors in the rateof evolution postulated by Fisher et al. We do, however, find marginalevidence for non-linearity in the PSC 60-μm flux scale, in the sensethat faint sources may have fluxes overestimated by about 5per centcompared with bright sources. We update some of the previous scientificanalyses to assess the changes. The main new results are as follows. (1)The luminosity function is very well determined overall but is uncertainby a factor of several at the very highest luminosities(L_60μm>5x10^12L_solar), as this is where the remainingunidentified objects are almost certainly concentrated. (2) Thebest-fitting rate of evolution is somewhat lower than our previousestimate; expressed as pure density evolution with density varying as(1+z)^p, we find p=5.6+/-2.3. Making a rough correction for the possible(but very uncertain) non-linearity of fluxes, we find p=4.5+/-2.3. (3)The dipole amplitude decreases a little, and the implied value of thedensity parameter, assuming that IRAS galaxies trace the mass, isΩ=0.9(+0.45, -0.25). (4) Finally, the estimate of density varianceon large scales changes negligibly, still indicating a significantdiscrepancy from the predictions of simple cold dark matter cosmogonies.
| Warm IRAS sources from the point source catalog. IV. Extended optical line emission.
We present a list of objects observed to have extended line emission inour spectroscopic survey of infrared-warm AGN. Slit spectroscopic datawere obtained for 225 galaxies identified with objects in our compendiumof warm sources from the IRAS Point Source Catalog. Of these, 44 havespatially-resolved emission-line regions along the (arbitrarily placed)slit direction. Measured (projected) linear sizes of the ionized gasregions extend to >10kpc. In the case of the IRAS Seyfert galaxiesthe spatially extended line emission appears to have a lower ionizationstate than the nuclear emission. This contrasts with the warm IRASstarbust galaxies for which there is no significant difference betweenthe ionization states of the nuclear and extended emission. For thestarburst galaxies, there is a relation between the extent of starformation as seen at Hα and the far-IR colors, with more compactbursts having "warmer" colors.
| Warm IRAS sources. II - Optical spectroscopy of objects from the point source catalog
Optical spectra are presented for a sample of 563 high latitude IRASsources exhibiting relatively warm 25-60 micron colors, with a view tothe efficient identification of Seyfert galaxies. Spectroscopic data areobtained on 358 extragalactic objects. The present census is consistentwith an obscuration scheme for producing both types of Seyfert objectfrom a single parent population, although the origin of excess cool IRradiation from many Seyferts remains unclear.
| Warm IRAS sources. I. A. Catalogue of AGN candidates from the point source catalog
It was previously shown that a blue (warm) 60 to 25 micron infraredcolor provides a powerful parameter for discriminating between AGNs andnormal galaxies, and that the far-IR spectrum is therefore an efficienttool for finding new AGNs. A list of such AGN candidates based on warmIR sources from the IRAS Point Source Catalogue (PSC) is presented here.Identification data and finding charts are also given. In addition, thelist of warm IRAS sources is supplemented by a compendium of data fromthe IRAS PSC on detected sources identified with previously known AGNswhose infrared spectra do not bring them within this color selectioncriterion.
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