Bibcode
Bradli, J. C.; Bussmann, R. Shane; Riechers, Dominik A.; Clements, David; Perez-Fournon, I.
Bibliographical reference
American Astronomical Society, AAS Meeting #225, #251.13
Advertised on:
1
2015
Citations
0
Refereed citations
0
Description
Strong gravitational lensing has recently become one of the most
important tools for studying star formation properties in extremely high
redshift galaxies. Dust-obscured star-forming galaxies found at
far-infrared/sub-millimeter wavelengths are important in the assembly of
stellar mass and the evolution of massive galaxies. We present
Submillimeter Array (SMA) imaging of Lockman 102, a strongly lensed
submillimeter galaxy at z=5.29, discovered by the Herschel Space
Observatory. The system was observed at 250, 350, 500 and 1000 microns,
corresponding to rest frame wavelengths of 40, 56, 80, and 159 microns
respectively. The observations were targeted at the thermal dust
emission and the [CII] interstellar medium cooling line. We report an
estimated photometric redshift of ~1.9 for the lensing galaxy, making it
possibly the most distant lens currently known. We use uvmcmcfit, a
publicly available Markov Chain Monte Carlo software tool we have
developed for interferometric data, to fit lens models to Lockman 102.
The results obtained from uvmcmcfit suggest the lensed system is
composed of a single lensing galaxy and two extended sources. We have
strong constraints on an intrinsic flux density of Lockman 102 of 4.55
+ 0.45 mJy magnified by a factor of 12.5 + 1.2. From
a modified blackbody fit we compute an intrinsic far infrared luminosity
of 5.5e12 L⊙.This implies a star formation rate of ~950
M⊙ yr-1, making Lockman 102 an extremely
active dusty galaxy. We also compare Lockman 102 to other dusty luminous
starburst galaxies at similar redshift, HLS0918 (Rawle et al. 2014) and
AzTEC-3 (Riechers et al. 2014a) and determine it is among the most
luminous and active galaxies ~1 Gyr after the Big Bang. It is only with
strong lensing that the SMA is able to undertake such a detailed study
of a galaxy at this distance; the continued improvements from new
facilities such as ALMA offer a promising future in observing even more
distant lensed systems.