The Zwicky Transient Facility: Data Processing, Products, and Archive
arXiv:1902.01872 · doi:10.1088/1538-3873/aae8ac
Abstract
The Zwicky Transient Facility (ZTF) is a new robotic time-domain survey currently in progress using the Palomar 48-inch Schmidt Telescope. ZTF uses a 47 square degree field with a 600 megapixel camera to scan the entire northern visible sky at rates of ~3760 square degrees/hour to median depths of g ~ 20.8 and r ~ 20.6 mag (AB, 5sigma in 30 sec). We describe the Science Data System that is housed at IPAC, Caltech. This comprises the data-processing pipelines, alert production system, data archive, and user interfaces for accessing and analyzing the products. The realtime pipeline employs a novel image-differencing algorithm, optimized for the detection of point source transient events. These events are vetted for reliability using a machine-learned classifier and combined with contextual information to generate data-rich alert packets. The packets become available for distribution typically within 13 minutes (95th percentile) of observation. Detected events are also linked to generate candidate moving-object tracks using a novel algorithm. Objects that move fast enough to streak in the individual exposures are also extracted and vetted. The reconstructed astrometric accuracy per science image with respect to Gaia is typically 45 to 85 milliarcsec. This is the RMS per axis on the sky for sources extracted with photometric S/N >= 10. The derived photometric precision (repeatability) at bright unsaturated fluxes varies between 8 and 25 millimag. Photometric calibration accuracy with respect to Pan-STARRS1 is generally better than 2%. The products support a broad range of scientific applications: fast and young supernovae, rare flux transients, variable stars, eclipsing binaries, variability from active galactic nuclei, counterparts to gravitational wave sources, a more complete census of Type Ia supernovae, and Solar System objects.
30 pages, 16 figures, Published in PASP Focus Issue on the Zwicky Transient Facility (doi: 10.1088/1538-3873/aae8ac)
References in corpus (6)
- Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
- The Zwicky Transient Facility: System Overview, Performance, and First Results
- The Zwicky Transient Facility Alert Distribution System
- A Morphological Classification Model to Identify Unresolved PanSTARRS1 Sources: Application in the ZTF Real-Time Pipeline
- The IPAC Image Subtraction and Discovery Pipeline for the intermediate Palomar Transient Factory
- Small near-Earth asteroids in the Palomar Transient Factory survey: A real-time streak-detection system
Cited by in corpus (12)
- The Zwicky Transient Facility: System Overview, Performance, and First Results
- The Zwicky Transient Facility: Science Objectives
- The Zwicky Transient Facility: Surveys and Scheduler
- Machine Learning for the Zwicky Transient Facility
- Follow-up of the Neutron Star Bearing Gravitational Wave Candidate Events S190425z and S190426c with MMT and SOAR
- ZTF 18aaqeasu (SN 2018byg): A Massive Helium-shell Double Detonation on a Sub-Chandrasekhar Mass White Dwarf
- A new class of pulsating hot subdwarfs
- 2900 square degree search for the optical counterpart of short gamma-ray burst GRB 180523B with the Zwicky Transient Facility
- ZTF18aalrxas: A Type IIb Supernova from a very extended low-mass progenitor
- Multiple Outbursts of Asteroid (6478) Gault
- Towards Efficient Detection of Small Near-Earth Asteroids Using the Zwicky Transient Facility (ZTF)
- A code for robust astrometric solution of astronomical images