AuthorRudnick, Gregory Howard
KeywordsPhysics, Astronomy and Astrophysics.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractWe present the first results from the F̲aint I̲nfra-R̲ed E̲xtragalactic S̲urvey (FIRES) of the Rubble Deep Field (HDF) South. Using a combination of very deep ground-based near infrared (NIR) data with the WFPC2 Hubble Space Telescope data, we constructed a K(s)-band selected sample to K(s,AB) ≤ 26.0. To interpret this data, we developed a new photometric redshift technique and tested it using spectroscopic redshifts in the HDF-N and HDF-S. Our accuracy was Δz/(1 + z) ≈ 0.07 for z < 6. We derived realistic error estimates in z(phot) by accounting both for template mismatch and for the dependence of the redshift uncertainty on the photometric errors. We estimated the rest-frame optical luminosities from an initial NIR data set and found 90 times more galaxies at 2 < z < 3.5 and Lʳᵉˢᵗ(B) > 5 x 10¹⁰ h⁻² L(⊙,B) than are expected from local luminosity functions. This discrepancy can be explained if L*, B increases by a factor of 2.4-3.2 with respect to locally determined values. Using all available NIR data in the HDF-S, we then derived the rest-frame colors (U - B)(rest), (B - V)(rest), and (U - V)(rest) of all galaxies with K(s,AB) < 25. Eight of the 12 rest-frame optically reddest galaxies at 2 < z(phot) < 3.2 would have been missed by the U-dropout selection criteria. Three of the galaxies at z > 2 have strong rest-frame optical breaks with colors corresponding to those of present day Sbc's. Using theoretical relations between the color and stellar mass-to-light ratio M/L , we estimated the M/L and stellar mass M . Using these estimates, we found that the most massive galaxies at any redshift are those with the reddest rest-frame colors and those that would be missed by the U-dropout technique. We also found that the stellar mass budget at z < 3.2 has significant contributions from galaxies redder than local Scd's. There are, however, large uncertainties in the M/L analysis and we have a relatively small field. Confirmation of these results will require additional modeling, observations over a larger area, and extensive spectroscopic follow up. We found an intrinsically bright (Lʳᵉˢᵗ(V) =5.10x10¹⁰ h⁻² L(⊙,V)) U-dropout galaxy in the HDF-S with z(spec) = 2.793. This galaxy has an extended ring-like morphology, and a co-moving diameter of ≳ 9.4 h⁻¹ Kpc for a Ω(M) = 0.3, Ω(Λ) = 0.7 cosmology. The light profile appears more centrally concentrated and symmetric at longer wavelengths and this object may have an older population superimposed on a star-forming disk.
Degree ProgramGraduate College