Physics
Scientific paper
Oct 2008
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008phdt.......426s&link_type=abstract
Ph.D. thesis, University of Oxford
Physics
Scientific paper
This thesis presents the study of a sample of 70μm-selected galaxies at z<1, with multiwavelength data provided by the All-wavelength Extended Groth Strip International Survey (AEGIS). Of the 178 sources detected at 70 μm down to 4.2mJy (5sigma), the 43 sources with available spectroscopic redshifts were primarily used in the data analysis. The galaxies' SEDs reveal an energetic output almost entirely in the infrared, characterised by an SED peak longward of 80 μm due to thermally reprocessed radiation by dust in cool equilibrium. 95% have starburst-type SEDs, the remaining few objects showing signs of a mid-IR power-law continuum. Bolometric luminosities are calculated to be in the range 10^10×10^13 L_solar,with the majority of the sources falling in the Luminous and Ultraluminous InfraRed Galaxy(LIRG and ULIRG) regime. Quantitative analysis of the sources' infrared properties, using various model SED templates, reveals characteritics that are potentially discrepant to those of local counterparts, particularly with respect to the amount of dust obscuration and/or size of the emitting region. In terms of their multiwavelength properties, there is no evident radio and X-ray excess emission over what is expected from star-formation related processes. This acts as evidence towards star-formation, as opposed to an active nucleus, being the dominant energy source in all objects, bar the ones with a power-law type SED. Star Formation Rates (SFRs) are estimated using various indicators, including optical emission lines and the infrared, radio and X-ray continuum. Radio and Infrared SFRs range from 10-1000 solar masses/yr. Optical and X-ray SFRs fall short by a factor of at least 10 and up to 100 in severe cases, most likely due to optical extinction for the former and molecular gas absorption for the latter. Stellar masses and optical morphologies, reveal that the majority of sources are massive isolated spirals, but with a significant percentage of mergers which increases with total infrared luminosity. The high redshift galaxies are characterised by burst-dominated mass assembly, in contrast to the low redshift objects which show a more quiescent star formation history. Finally, the infrared luminosity function reveals strong evolution, clearly evident at z>0.5, manifesting as tail with a very shallow drop-off at the high luminosity end.
No associations
LandOfFree
The properties of obscured galaxies at z<1 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The properties of obscured galaxies at z<1, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The properties of obscured galaxies at z<1 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-865146