SDSS J1029+2623 is a double imaged quasar. It is separated into two components with a large angular separation of 22.5 arcseconds,making it the largest known separation lens.[3][4][5] Like SDSS J1004+4112, it is lensed by a massive galaxy cluster located at (z) 0.588 with an Einstein radius of 15.2 ± 0.5 arcseconds and a bolometric luminosity of 9.6 x 1044 erg s-1, making it the second known quasar lensed by a cluster.[6][7][3] Further observations discovered there is a third component in the lens system with its spectrum displaying emission and absorption features, however it has a redder continuum. Several lensed arcs are also identified in the system.[8] In the field of SDSS J1029+2623, several galaxies are discovered at redshifts of 2.181, 3.027 and 5.062 based on spectroscopy data from the Large Area Telescope.[6][9] A dark matter clump was discovered in a slight offset position from component B with a measured mass of 109 Mʘ.[1]
The quasar shows time-delays according to Janine Fohlmeister. Based on optical monitoring data obtained over 5.4 years, the time delay is estimated to be 744 ± 10 days with component A shown leading component B and component C. Fohlmeister suggested it displays weak evidence of microlensing, likely arising from a smaller galaxy responsible for its flux ratio anomaly. However an observation in 2020, confirmed no signs of microlensing but evidence of extinction.[10][11] In combined light-curves, the intrinsic variability of SDSS J1029+2623 displays an amplitude at 100 days of 0.15 ± 0.03 magnitude with a power-law slope of 0.32 ± 0.02.[10]
Observations showed both of the components of SDSS J1029+2623 display narrow absorption-lines in their spectrum with ejectionvelocities of 1000 kilometers per seconds. According to results, there are 66 detected narrow absorption-lines of which 24 of them are classified as intrinsic. There are also broader proximity absorption lines (PALs) which are created in outflowing gas with measured electron densities of 8.7 x 103 cm-3 with multiple sightline observations suggesting they have larger sizes compared to sightline projection distances.[12]
SDSS J1029+2623 has outflowing wind originating from its accretion disk. When observed in mid-resolution spectroscopy, the carbon absorption-line profile shows no clear variation towards any lines of sight. It is also found to deblend into more than 10 narrow components, indicating it is related to the quasar.[13] The absorption profiles of both A and B components remained constant since observations conducted in 2010, suggesting not time variability but differences along sightlines. It is suggested the outflow wind in SDSS J1029+2623 is confined to both a continuum source and a broad emission-line region measuring a size of 0.09 parsecs since the residual flux located at the bottom of absorption lines are closer to zero. The estimated supermassive black hole mass for SDSS J1029+2623 is 108.72Mʘ.[14]
