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Paper: Differential Lensing Effects in High-z Sources: Constraining the Size and Shape of the Emitting Regions
Volume: 375, From Z-Machines to ALMA: (Sub)Millimeter Spectroscopy of Galaxies
Page: 250
Authors: Krips, M.; Neri, R.; Eckart, A.; Barvainis, R.; Peck, A.; Downes, D.; Planesas, P.; Martin-Pintado, J.; Iono, D.; Petitpas, G.
Abstract: One of the greatest obstacles in determining the physical parameters of galaxies in the early universe is our inability to accurately constrain the sizes of the sources detected. Current cutting-edge mm/submm interferometers such as the Submillimeter Array (SMA) and the Plateau de Bure Interferometer (PdBI) yield angular resolutions of about 1″, which is in most cases not sufficient to resolve the observed emission at high z. However, if the high-redshift source is gravitationally lensed by an intervening galaxy, the angular resolution can be improved by up to two orders of magnitude, as demonstrated in the case of the Cloverleaf galaxy. Light from extended regions is deflected in a different way than light from compact structures, so that the lensed images set tight constraints on their true sizes and shapes. We will discuss the use of such differential lensing effects for three gravitationally lensed high-redshift quasars: Q0957+561 (z = 1.41), SBS1520+530 (z = 1.86), and APM08279+5255 (z = 3.9). We have recently detected molecular gas emission traced by CO in the first two sources, doubling the number of CO detections in this mostly unexplored redshift range of z = 1 − 2. We will be able to use this technique as well to place even tighter constraints on the size of the dust emission in APM08279+5255, using the new very extended configurations of the SMA and PdBI with their angular resolutions of 0.3″ − 0.4″.
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