In continuation of my lensed galaxy project, here is the brightest lensed galaxy in the cluster SDSS J1138+2754 (animated)
The overlay is the Hubble image for the same field. The arc also appears on the SDSS survey image and PanSTARRS, which is a good sign it can be imaged by amateur gear.
Bayliss et. al. (Ap J supplement 193:8 Mar 2011) provides Gemini/GMOS spectroscopy of the cluster members, which gives the lensing (foregrond) galaxy cluster at a redshift (z) of 0.44 and this lensed galaxy at z = 1.33. This equates to a comoving distance of about 5.5 and 13.4 billion light years; there are also lensed galaxies at z=0.9 and 1.45. These lensed galaxies appear as arcs which are large relative to the foreground galaxies on the images and so surveys for them are called giant arc surveys. This one was found in 2000 as part of the Sloan Digital Sky Survey Giant Arcs Survey.
The lensed arc brightness is about g=21.8. The lensing galaxy brightness is around 19th magnitude. Most of the things that look like stars in the image are in fact galaxies. For size scale, the arc is about ten arc seconds across. The best stars on the full frame image have a FWHM of about 2.1 but unfortunately it appears that I need to collomate as this part of the frame is a little worse which is why there's some eccentricity.
My image is mono but shown in the SAO DS9 false color "bone".
Image acquisition: 207x60s, Meade 16" f/10 SCT, ASI6200 mono camera binned 3x, unguided.
Edited by 555aaa, 23 April 2025 - 01:31 PM.
