Modeling of the HERMES J105751.1+573027 submillimeter source lensed by a dark matter dominated foreground group of galaxies

R. Gavazzi, A. Cooray, A. Conley, J. E. Aguirre, A. Amblard, R. Auld, A. Beelen, A. Blain, R. Blundell, J. Bock, C. M. Bradford, C. Bridge, D. Brisbin, D. Burgarella, P. Chanial, E. Chapin, N. Christopher, D. L. Clements, P. Cox, S. G. Djorgovski, C. D. Dowell, S. Eales, L. Earle, T. P. Ellsworth-Bowers, D. Farrah, A. Franceschini, H. Fu, J. Glenn, E. A. González Solares, M. Griffin, M. A. Gurwell, M. Halpern, E. Ibar, R. J. Ivison, M. Jarvis, J. Kamenetzky, S. Kim, M. Krips, L. Levenson, R. Lupu, A. Mahabal, P. D. Maloney, C. Maraston, L. Marchetti, G. Marsden, H. Matsuhara, A. M. J. Mortier, E. Murphy, B. J. Naylor, R. Neri, H. T. Nguyen, S. J. Oliver, A. Omont, M. J. Page, A. Papageorgiou, C. P. Pearson, I. Pérez-Fournon, M. Pohlen, N. Rangwala, J. I. Rawlings, G. Raymond, D. Riechers, G. Rodighiero, I. G. Roseboom, M. Rowan-Robinson, B. Schulz, Douglas Scott, K. S. Scott, P. Serra, N. Seymour, D. L. Shupe, A. J. Smith, M. Symeonidis, K. E. Tugwell, M. Vaccari, E. Valiante, I. Valtchanov, A. Verma, J. D. Vieira, L. Vigroux, L. Wang, J. Wardlow, D. Wiebe, G. Wright, C. K. Xu, G. Zeimann, M. Zemcov, J. Zmuidzinas

April 2011

Abstract

We present the results of a gravitational lensing analysis of the bright $z s = 2.957$ sub-millimeter galaxy (SMG), HERMES J105751.1+573027 found in {it Herschel}/SPIRE Science Demonstration Phase data from the Herschel Multi-tiered Extragalactic Survey (HerMES) project. The high resolution imaging available in optical and Near-IR channels, along with CO emission obtained with the Plateau de Bure Interferometer, allow us to precisely estimate the intrinsic source extension and hence estimate the total lensing magnification to be $m u = 10.9 p m 0.7$ . We measure the half-light radius $R{rm eff} $o f t h e s o u r c e i n t h e r e s t - f r a m e N e a r - U V a n d$ V $b a n d s t h a t c h a r a c t e r i z e t h e u n o b s c u r e d l i g h t c o m i n g f r o m s t a r s a n d f i n d$ R{rm eff,*}= [2.0 pm 0.1] $k p c, i n g o o d a g r e e m e n t w i t h r e c e n t s t u d i e s o n t h e S u b m i l l i m e t e r G a l a x y p o p u l a t i o n . T h i s l e n s m o d e l i s a l s o u s e d t o e s t i m a t e t h e s i z e o f t h e g a s d i s t r i b u t i o n ($ R{rm eff,gas}= [1.1pm0.5] $) k p c b y m a p p i n g b a c k i n t h e s o u r c e p l a n e t h e C O (J = 5 - 4) t r a n s i t i o n l i n e e m i s s i o n . T h e l e n s m o d e l i n g y i e l d s a r e l a t i v e l y l a r g e E i n s t e i n r a d i u s$ R{rm Ein}= 4farcs10 pm 0farcs02 $, c o r r e s p o n d i n g t o a d e f l e c t o r v e l o c i t y d i s p e r s i o n o f [$ 483pm 16] ,kms $. T h i s s h o w s t h a t H E R M E S J 105751.1 + 573027 i s l e n s e d b y a i t g a l a x y g r o u p - s i z e d a r k m a t t e r h a l o a t r e d s h i f t$ zlsim 0.6 $. T h e p r o j e c t e d d a r k m a t t e r c o n t r i b u t i o n l a r g e l y d o m i n a t e s t h e m a s s b u d g e t w i t h i n t h e E i n s t e i n r a d i u s w i t h$ f{rm dm}(<R{rm Ein})sim 80% $. T h i s f r a c t i o n r e d u c e s t o$ f{rm dm}(<R{rm eff,G1}simeq 4.5kpc)sim 47% $w i t h i n t h e e f f e c t i v e r a d i u s o f t h e m a i n d e f l e c t i n g g a l a x y o f s t e l l a r m a s s$ M_{rm *,G1}=[8.5pm 1.6] times 10^{11}msun $. A t t h i s s m a l l e r s c a l e t h e d a r k m a t t e r f r a c t i o n i s c o n s i s t e n t w i t h r e s u l t s a l r e a d y f o u n d f o r m a s s i v e l e n s i n g e l l i p t i c a l s a t$ zsim0.2$ from the SLACS survey.

Type

Journal article

http://arxiv.org/abs/1104.4119v1