J-PAS: the Javalambre-physics of the accelerated Universe astrophysical survey Academic Article uri icon


  • The Javalambre-Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Observatory in Spain with a purpose-built, dedicated 2.5m telescope and a 4.7deg² camera with 1.2Gpix. Starting in 2015, J-PAS will observe 8500deg² of Northern Sky and measure 0.003(1+z) precision photometric redshifts for 9×107 LRG and ELG galaxies plus several million QSOs, about 50 times more than the largest current spectroscopic survey, sampling an effective volume of ∼ 14 Gpc3 up to z = 1.3. J-PAS will be the first radial BAO experiment to reach Stage IV. J-PAS will also detect and measure the mass of 7 × 105 galaxy clusters and groups, setting constrains on Dark Energy which rival those obtained from BAO measurements. Thanks to the superb characteristics of the Javalambre site (seeing ∼ 0.7"), J-PAS is expected to obtain a deep, sub-arcsec image of the northern sky, which combined with its unique photo-z precision will produce one of the most powerful cosmological lensing surveys before the arrival of Euclid. In addition, J-PAS unprecedented spectral time domain information will enable a self-contained SN survey that, without the need for external spectroscopic follow-up, will detect, classify and measure σz ∼ 0.5% redshifts for ∼ 4000 SNeIa and ∼ 900 core-collapse SNe. The key to the J-PAS potential is its innovative approach: the combination of 54 145Å filters, placed 100Å apart, and a multi-degree field of view (FOV) is a powerful “redshift machine”, with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. Moreover, since the J-PAS camera is equivalent to a very large, 4.7deg² “IFU”, it will produce a time-resolved, 3D image of the Northern Sky with a very wide range of Astrophysical applications in Galaxy Evolution, the nearby Universe and the study of resolved stellar populations. J-PAS will have a lasting legacy value in many areas of Astrophysics, serving as a fundamental dataset for future Cosmological projects. Keywords: Dark Energy, Cosmology, SNIa, Large Scale Structure, Baryonic Acoustic Oscillations, Lensing, Dark Matter, Galaxy Evolution, Stars, Solar System, Transients, Telescopes, Instrumentation, Photometric Redshifts


publication date

  • March 20, 2014