A strong-lensing elliptical galaxy in the MaNGA survey

作者：Smith Russell J^*

来源：Monthly Notices of the Royal Astronomical Society, 2017, 464(1): L46-L50.

DOI：10.1093/mnrasl/slw174

• gravitational lensing: strong
• galaxies: elliptical and lenticular, cD

I report discovery of a new galaxy-scale gravitational lens system, identified using public data from the Mapping Galaxies at Apache Point Observatory MaNGA) survey, as part of a systematic search for lensed background line emitters. The lens is SDSS J170124.01+ 372258.0, a giant elliptical galaxy with velocity dispersion sigma = 256 km s(-1), at a redshift of z(l) = 0.122. After modelling and subtracting the target galaxy light, the integral-field data cube reveals [O II], [O III] and Ha emission lines corresponding to a source at z(s) = 0.791, forming an identifiable ring around the galaxy centre. If the ring is formed by a single lensed source, then the Einstein radius is R-Ein approximate to 2.3 arcsec, projecting to similar to 5 kpc at the distance of the lens. The total projected lensing mass is M-Ein = 3.6 +/- 0.6) x 10(11) M-circle dot and the total J-band mass-to-light ratio is 3.0 +/- 0.7 solar units. Plausible estimates of the likely dark matter content could reconcile this with a Milky Way-like initial mass function IMF), for which M/L approximate to 1.5 is expected, but heavier IMFs are by no means excluded with the present data. An alternative interpretation of the system, with a more complex source plane, is also discussed. The discovery of this system bodes well for future lens searches based on MaNGA and other integral-field spectroscopic surveys.

• 出版日期2017-1