SearcharxivSearch

arXiv subjects

E. McKenzie

Publications and source records attributed to E. McKenzie.

2 recordsLinked to original sources

Low Resolution Spectral Templates For Galaxies From 0.2 -- 10 microns

We built an optimal basis of low resolution templates for galaxies over the wavelength range from 0.2 to 10 $μ$m using a variant of the algorithm presented by Budavari et al. (2000). We derived them using eleven bands of photometry from the NDWFS, FLAMEX, zBoötes and IRAC Shallow surveys for 16033 galaxies in the NDWFS Boötes field with spectroscopic redshifts measured by the AGN and Galaxy Evolution Survey. We also developed algorithms to accurately determine photometric redshifts, K corrections and bolometric luminosities using these templates. Our photometric redshifts have an accuracy of $σ_z/(1+z) = 0.04$ when clipped to the best 95%. We used these templates to study the spectral type distribution in the field and to estimate luminosity functions of galaxies as a function of redshift and spectral type. In particular, we note that the 5-8$μ$m color distribution of galaxies is bimodal, much like the optical g--r colors.

astro-ph

Photometric Redshifts in the IRAC Shallow Survey

Accurate photometric redshifts are calculated for nearly 200,000 galaxies to a 4.5 micron flux limit of ~13 uJy in the 8.5 deg^2 Spitzer/IRAC Shallow survey. Using a hybrid photometric redshift algorithm incorporating both neural-net and template-fitting techniques, calibrated with over 15,000 spectroscopic redshifts, a redshift accuracy of σ= 0.06(1+z) is achieved for 95% of galaxies at 0 1) galaxy clusters. We present one such spectroscopically confirmed cluster at =1.24, ISCS J1434.5+3427. Finally, we present a measurement of the 4.5 micron-selected galaxy redshift distribution.

astro-ph