Julie L. Wardlow, Asantha Cooray, Francesco De Bernardis, A. Amblard, V. Arumugam, H. Aussel, A. J. Baker, M. Béthermin, R. Blundell, J. Bock, A. Boselli, C. Bridge, V. Buat, D. Burgarella, R. S. Bussmann, J. Calanog, J. M. Carpenter, C. M. Casey, N. Castro-Rodríguez, A. Cava, P. Chanial, S. C. Chapman, D. L. Clements, A. Conley, P. Cox, C. D. Dowell, S. Dye, S. Eales, D. Farrah, A. Franceschini, D. T. Frayer, C. Frazer, Hai Fu, R. Gavazzi, J. Glenn, M. Griffin, M. A. Gurwell, A. I. Harris, E. Hatziminaoglou, R. Hopwood, E. Ibar, R. J. Ivison, S. Kim, G. Lagache, L. Levenson, L. Marchetti, G. Marsden, M. Negrello, R. Neri, H. T. Nguyen, B. O'Halloran, S. J. Oliver, A. Omont, M. J. Page, P. Panuzzo, A. Papageorgiou, C. P. Pearson, I. Pérez-Fournon, M. Pohlen, D. Riechers, D. Rigopoulou, I. G. Roseboom, M. Rowan-Robinson, B. Schulz, D. Scott, N. Scoville, N. Seymour, D. L. Shupe, A. J. Smith, M. Symeonidis, M. Trichas, M. Vaccari, J. D. Vieira, M. Viero, L. Wang, C. K. Xu, L. Yan, M. Zemcov
We present a list of 13 candidate gravitationally lensed submillimeter galaxies (SMGs) from 95 square degrees of the Herschel Multi-tiered Extragalactic Survey, a surface density of 0.14\pm0.04deg^{-2}. These sources have 500um flux densities (S_500) greater than 100mJy. Follow-up observations confirm gravitational lensing in 9 of the 13 systems (70%); the lensing status of the four remaining sources is undetermined. We also present a supplementary sample of 29 (0.31\pm0.06deg^{-2}) gravitationally lensed SMG candidates with S_500=80--100mJy, which are expected to contain a higher fraction of interlopers than the primary candidates. The number counts of the candidate lensed galaxies are consistent with a simple statistical model of the lensing rate, which uses a foreground matter distribution, the intrinsic SMG number counts, and an assumed SMG redshift distribution. The model predicts that 43--83% of our S_500>100mJy candidates are strongly gravitationally lensed, with the brightest sources being the most robust; this is consistent with the observational data. Our statistical model also predicts that, on average, lensed galaxies with S_500=100mJy are magnified by factors of ~6, with brighter galaxies having progressively higher average magnification. 50% of the sources are expected to have intrinsic 500um flux densities less than 30mJy. Thus, samples of strongly gravitationally lensed SMGs, such as those presented here, probe below the nominal Herschel detection limit at 500um. They are ideal targets for the detailed study of the physical conditions in distant dusty, star-forming galaxies, with unprecedented spatial resolution achieved due to the lensing magnification.
View original:
http://arxiv.org/abs/1205.3778
No comments:
Post a Comment