Local Luminosity Function at 15 Microns and Galaxy Evolution Seen by ISOCAM 15 Micron Surveys

A local luminosity function at 15 μm is derived using the bivariate (15 μm vs. 60 μm luminosity) method, based on the newly published ISOCAM LW3 band (15 μm) survey of the very deep IRAS 60 μm sample in the north ecliptic pole region (NEPR). New IRAS 60 μm fluxes are obtained using the SCANPI/SUPERSCANPI software at the new ISOCAM positions of the sources in the sample. It is found to be in excellent agreement with the 15 μm local luminosity function published by Xu et al., which is derived from the predicted 15 μm luminosities of a sample of IRAS 25 μm-selected galaxies. Model predictions of number counts and redshift distributions based on the local luminosity function and assumptions of its evolution with redshift are calculated and compared with the data of ISOCAM 15 μm surveys. Strong luminosity evolution on the order of L ∝ (1 + z)4.5 is suggested in these comparisons, while pure density evolution can be ruled out with high confidence. The sharp peak at about 0.4 mJy in the Euclidean normalized differential counts at 15 μm can be explained by the effects of mid-infrared broadband emission features, eliminating the need for any hypothesis for a "new population." It is found that the contribution from the population represented by ISOCAM 15 μm sources can account for the entire IR/submillimeter background, leaving little room for any missing "new population" which can be significant energy sources of the IR/submillimeter sky.

[1]  L. Pozzetti,et al.  High-redshift galaxies in the Hubble Deep Field- II. Colours and number counts , 1998, astro-ph/9803144.

[2]  Chris Pearson,et al.  Starburst galaxy contributions to extragalactic source counts , 1996 .

[3]  E. Dwek,et al.  On the determination of the cosmic infrared background radiation from the high-energy spectrum of extragalactic gamma-ray sources , 1994 .

[4]  J. Puget.  The interstellar dust emission seen by ISO. , 1998 .

[5]  R. Ellis,et al.  The 60-μ and far-infrared luminosity functions of IRAS galaxies , 1990 .

[6]  D. Shupe,et al.  Emission Features and Source Counts of Galaxies in the Mid-Infrared , 1998, astro-ph/9806194.

[7]  E. L. Wright,et al.  The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background. I. Limits and Detections , 1998, astro-ph/9806167.

[8]  L. Pozzetti,et al.  The Star Formation History of Field Galaxies , 1997, astro-ph/9708220.

[9]  O. Fèvre,et al.  The Canada-France Redshift Survey: The Luminosity Density and Star Formation History of the Universe to z ~ 1 , 1996, astro-ph/9601050.

[10]  C. Bennett,et al.  The Spectrum of the Extragalactic Far-Infrared Background from the COBE FIRAS Observations , 1998, astro-ph/9803021.

[11]  T. Stanev,et al.  Constraints on the Extragalactic Infrared Background from Gamma-Ray Observations of Markarian 501 , 1997, astro-ph/9708162.

[12]  C. Beichman,et al.  What COBE might see - The far-infrared cosmological background , 1991 .

[13]  J. Sulentic,et al.  Infrared emission in paired galaxies. II - Luminosity functions and far-infrared properties , 1991 .

[14]  M. Malkan,et al.  The Extended 12-micron galaxy sample , 1993, astro-ph/9306013.

[15]  ROBERT E. Williams,et al.  The Hubble Deep Field: Observations, Data Reduction, and , 1996, astro-ph/9607174.

[16]  J. Huchra,et al.  The Local Luminosity Function at 25 Microns , 1998, astro-ph/9803149.

[17]  B. Soifer,et al.  The number counts and infrared backgrounds from infrared-bright galaxies , 1991 .

[18]  B. Madore,et al.  The IRAS bright galaxy sample. II - The sample and luminosity function , 1987 .

[19]  N. B. Suntzeff,et al.  Supernova Limits on the Cosmic Equation of State , 1998, astro-ph/9806396.

[20]  Rodger I. Thompson,et al.  Near-Infrared Camera and Multi-Object Spectrometer Observations of the Hubble Deep Field: Observations, Data Reduction, and Galaxy Photometry , 1999 .

[21]  C. Surace,et al.  The Universe as Seen by ISO , 1999 .

[22]  J. Houck,et al.  A very deep IRAS survey at L = 97 deg, B = 30 deg , 1987 .

[23]  H. Aussel,et al.  ISOCAM observations of the very deep IRAS 60 micron sample in the NEP region ? I. The data , 2000 .

[24]  L. Danese,et al.  Luminosity Evolution and Dust Effects in Distant Galaxies: Implications for the Observability of the Early Evolutionary Phases , 1994 .

[25]  M. Rowan-Robinson,et al.  Modelling the IRAS zodiacal emission , 1990 .

[26]  J. Puget,et al.  A New Component of the Interstellar Matter: Small Grains and Large Aromatic Molecules , 1989 .

[27]  J. Gunn,et al.  Study of Deep IRAS Fields at 60 micron , 1995 .

[28]  Hans Ulrik Nørgaard-Nielsen,et al.  Observations of the Hubble Deep Field with the Infrared Space Observatory V. Spectral energy distributions starburst models and star formation history , 1997 .

[29]  C. Lonsdale,et al.  Galaxy evolution and large-scale structure in the far-infrared. II, The IRAS Faint Source Survey , 1990 .

[30]  G. Neugebauer,et al.  The properties of infrared galaxies in the local universe , 1991 .

[31]  J. Houck,et al.  Tests of Starburst Galaxy Evolution at the North Ecliptic Pole , 1996 .

[32]  E. L. Wright,et al.  The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background. IV. Cosmological Implications , 1997, astro-ph/9806129.

[33]  B. Madore,et al.  Astrophysics with Infrared Surveys: A Prelude to SIRTF , 1999 .

[34]  John P. Huchra,et al.  A Redshift Survey of IRAS Galaxies. II. Methods for Determining Self-consistent Velocity and Density Fields , 1991 .

[35]  O. Fèvre,et al.  The Canada-UK Deep Submillimeter Survey: First Submillimeter Images, the Source Counts, and Resolution of the Background , 1998, astro-ph/9808040.