Please use this identifier to cite or link to this item: http://hdl.handle.net/10481/28406

 Title: The AMIGA sample of isolated galaxies: III IRAS data and infrared diagnostics Authors: Lisenfeld, UteVerdes-Montenegro, L.Sulentic, J.Leon, S.Espada, D.Bergond, G.García, E.Sabater, J.Santander-Vela, J. D.Verley, S. Issue Date: 2007 Abstract: Aims. We describe the mid- (MIR) and far- (FIR) infrared properties of a large (-1000) sample of the most isolated galaxies in the local Universe. This sample is intended as a "nurture-free'' zero point against which more environmentally influenced samples can be compared.Methods. We reprocess IRAS MIR/FIR survey data using the ADDSCAN/SCANPI utility for 1030 out of 1050 galaxies from the Catalogue of Isolated Galaxies (CIG) as part of the AMIGA project. We focus on diagnostics (FIR luminosity $L_{\rm FIR}$, $R=\log(L_{\rm FIR}/L_{B})$, and IRAS colours) thought to be sensitive to effects of environment or interaction.Results. The distribution of $\log(L_{\rm FIR})$ sharply peaks from 9.0-10.5, with very few (<2%) galaxies above 10.5. Review of available optical images of the most FIR luminous galaxies finds the majority likely to be interacting systems missed in our earlier morphological reevaluation. The optically normalised luminosity diagnostic $R=\log(L_{\rm FIR}/L_{B})$ shows a sharply peaked distribution between 0.0 and -1.0. These results were compared to the magnitude limited sample of the Center for Astrophysics that was selected without environmental discrimination. This modestly (e.g., compared to cluster, binary galaxy, and compact group samples) environmentally affected sample shows a significantly higher mean $\log(L_{\rm FIR})$, and R, whereas the mean $\log(L_{B})$ is the same. Our sample shows a strong $L_{\rm FIR}$ vs. LB correlation, with a slope steeper than one ( $L_{\rm FIR} \propto L_{B}^{1.41}$). Interacting galaxies were found above this correlation, showing an enhancement in $L_{\rm FIR}$. With respect to the IRAS colours, we found higher $F_{\rm 60}/F_{\rm 100}$ values for ellipticals and late-type galaxies than for spirals, indicating a higher dust temperature. The mean value of $F_{\rm 60}/F_{\rm 100}$ was found to be lower than for interacting samples from the literature.Conclusions. The results indicate that the FIR emission is a variable enhanced by interaction, and that our sample probably shows the lowest possible mean value. This attests to the utility of our sample for defining a nurture-free zero point. Sponsorship: This work has been partially supported by DGI Grant AYA 2005-07516-C02-01 and the Junta de Andalucía (Spain). UL acknowledges support by the research project ESP 2004-06870-C02-02. J.S. is partially supported by a sabbatical grant SAB2004-01-04 of the Spanish Ministerio de Educación y Ciencias. GB acknowledges support at the IAA/CSIC by an I3P contract (I3P-PC2005F) funded by the European Social Fund. Publisher: European Southern Observatory (ESO); Springer Verlag Keywords: GalaxiesEvolutionInteractionsLuminosity functionMass functionSurveysInfrared URI: http://hdl.handle.net/10481/28406 ISSN: 0004-63611432-0746 Rights : Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Citation: Lisenfeld, U.; et al. The AMIGA sample of isolated galaxies: III IRAS data and infrared diagnostics. Astronomy and Astrophysics, 462(2): 507-523 (2007). [http://hdl.handle.net/10481/28406] Appears in Collections: DFTC - Artículos

Files in This Item:

File Description SizeFormat