J-PAS Pathfinder confirms the optical quality of the JST/T250

2017-May-05 16:35
Comparison of the image quality of a J-PAS Pathfinder coadded image of M51, resulting from the combination of 6x10s single exposures with no filter (left), and a g band image from SDSS (right). The FWHM of the PSF in the Pathfinder’s image is ~0.4

Comparison of the image quality of a J-PAS Pathfinder coadded image of M51, resulting from the combination of 6x10s single exposures with no filter (left), and a g band image from SDSS (right). The FWHM of the PSF in the Pathfinder’s image is ~0.4". The image cutout is just 1/30 of the original J-PAS Pathfinder full frame. Credit: CEFCA; SDSS.

The J-PAS Pathfinder camera installed in the Javalambre Survey Telescope (JST/T250) has been able to obtain high-resolution images, close to the system capacity limit, in just two weeks of operation. The quality of the images shows the excellent performances of the JST/T250 telescope and the camera, as well as the magnificent conditions of the Pico del Buitre for observation.

After Pathfinder’s first light on February 20th, work began on the instrument development in the JST/T250 telescope by the engineering team and the group of night observations of CEFCA.

Within a few days, the work team was able to obtain images that reach PSFs (Point-Spread Function) of ~ 0.4" in terms of image quality, demonstrating the good performances of the instrumentation and its ability to carry out first-level observations.

The images were taken during the night of March 8th, focusing on the field in which the M51 galaxy is located. They were obtained by taking a sequence of 10s exposure images without filter under good seeing conditions. They revealed details of the structure of the galaxy with a high degree of clarity. This reflects the magnitude of the quality of the data that can reach the system, even in this set-up phase.

The J-PAS Pathfinder camera is the first scientific instrument of the JST/T250 telescope with which the mechanical parts of the interface between the telescope and the definitive scientific camera, JPCam, are being commissioned. It is an instrument designed by CEFCA and members of the J-PAS scientific collaboration, and whose assembly, set-up and verification has been made entirely by CEFCA.