COSMOS 5921+0638: Characterization and analysis of a new strong gravitationally lensed AGN

Astronomy and Astrophysics – Astrophysics – Cosmology and Extragalactic Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

12 pages, 12 figures. Updated to match A&A published version

Scientific paper

10.1051/0004-6361/200912091

[abridged] We present VLT/FORS1 spectroscopic follow-up observations and HST/WFPC2 imaging of the system COSMOS 5921+0638, which exhibits quadruply lensed images and a perfect Einstein ring. We investigate the nature of COSMOS 5921+0638 by studying its photometric, spectroscopic and physical properties. We completed both an environmental analysis and detailed analytical and grid-based mass modeling of the system. We measured the redshifts of the lensing galaxy in COSMOS 5921+0638 (z_l=0.551+/-0.001) and 9 additional galaxies in the field (5 of them at z~0.35). The redshift of the lensed source was inferred by identifying a candidate Lya line at z_s=3.14+/-0.05. The mass modeling reveals the requirement of a small external shear (gamma=0.038), which is slightly larger than the lensing contribution expected by galaxy groups along the line-of-sight (kappa_groups~0.01 and gamma_groups~0.005). The estimated time-delays between the different images are of the order of hours to half a week and the total magnification of the background source is mu~150. The measured mass-to-light ratio of the lensing galaxy within the Einstein ring is M/L_B~8.5+/-1.6. Our analysis indicates that the ring and point-like structures in COSMOS 5921+0638 consist of a lensed high redshift galaxy hosting a low luminosity AGN (LLAGN). Flux ratio anomalies observed in the lensed AGN images are probably due to microlensing by stars in the lensing galaxy and/or a combination of static phenomena. Because of its short time-delays and the possibility of microlensing, COSMOS 5921+0638 is a promising laboratory for future studies of LLAGNs.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

COSMOS 5921+0638: Characterization and analysis of a new strong gravitationally lensed AGN does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with COSMOS 5921+0638: Characterization and analysis of a new strong gravitationally lensed AGN, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and COSMOS 5921+0638: Characterization and analysis of a new strong gravitationally lensed AGN will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-355778

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.