Galaxies at High Redshift

摘要: Within just the last few years, we have advanced from knowing only a galaxies at z > 2 to having redshifts for nearly 1000 ∼ – 5 objects. The majority of this sample has been detected through photometric ‘drop-out’ technique used so successfully by Steidel and his collaborators. In addition, handful objects already 5, may 6! These data, plus that resulted in characterization star formation history universe, commonly known as ‘Madau plot’, which gives SFR per comoving volume vs. redshift present day = 0 5. Recently, realized dust significantly affected our estimates optical, developed approaches correct extinction. We now also increasingly good evidence substantial fraction (> 50%?) high occurs dust-enshrouded starbursts were 850 pm with submm bolometer SCUBA on JCMT telescope. will typically be too faint detect measure though those can provided valuable constraints. highest beyond are intriguing sources, but test even limits Keck HST. detailed study such sources well practical gravitationally-lensed objects, where magnification allows much more proto-galaxy’s structure, until larger space-based (NGST) ground-based (30-m plus) telescopes developed.