The Pan-STARRS1 Surveys (1612.05560v4)

Abstract: Pan-STARRS1 has carried out a set of distinct synoptic imaging sky surveys including the $3\pi$ Steradian Survey and the Medium Deep Survey in 5 bands ($grizy_{P1}$). The mean 5$\sigma$ point source limiting sensitivities in the stacked 3$\pi$ Steradian Survey in $grizy_{P1}$ are (23.3, 23.2, 23.1, 22.3, 21.4) respectively. The upper bound on the systematic uncertainty in the photometric calibration across the sky is 7-12 millimag depending on the bandpass. The systematic uncertainty of the astrometric calibration using the Gaia frame comes from a comparison of the results with Gaia: the standard deviation of the mean and median residuals ($ \Delta ra, \Delta dec $) are (2.3, 1.7) milliarcsec, and (3.1, 4.8) milliarcsec respectively. The Pan-STARRS system and the design of the PS1 surveys are described and an overview of the resulting image and catalog data products and their basic characteristics are described together with a summary of important results. The images, reduced data products, and derived data products from the Pan-STARRS1 surveys are available to the community from the Mikulski Archive for Space Telescopes (MAST) at STScI.

• The paper presents innovative survey design and a quad observation approach that optimizes imaging efficiency and captures transient phenomena.
• It details a robust image processing pipeline that achieves photometric precision of 12 millimags and astrometric accuracy within 20 milliarcseconds.
• The surveys advanced our understanding of near-Earth objects, galactic structures, and transient events, setting a benchmark for future astronomical missions.

An Overview of the Pan-STARRS1 Surveys

The Pan-STARRS1 (PS1) Surveys, as documented by Chambers et al., constitute a comprehensive astronomical imaging project designed to investigate a wide array of phenomena across the universe. The PS1 system employs an innovative wide-field imaging capability developed at the University of Hawaii's Institute for Astronomy. These surveys were conducted using the Pan-STARRS Telescope #1, an advanced facility equipped to extend our understanding of topics ranging from the dynamic events in our solar system to the structure and expansion of the universe.

Survey Design and Methodology

The Pan-STARRS1 initiative encompasses several core survey programs, with an emphasis on the $3\pi$ Steradian Survey and the Medium Deep Survey. The $3\pi$ survey aimed to cover the entire sky north of a declination of -30 degrees across five photometric bands (g, r, i, z, y). The Medium Deep Survey targeted specific areas of scientific interest to obtain deeper imaging data. Complementary to these, specialized surveys included a solar system survey for identifying near-Earth objects and a stellar transit survey.

The PS1 Surveys utilized a sophisticated scheduling strategy to optimize observational efficiency and scientific output. An innovative aspect was the deployment of a "quad" observation approach, optimizing the capture of transient and celestial objects with rapid and successive imaging sequences. This approach was instrumental in refining the photometric calibration and improving the reliability of source detection and identification.

Data Processing and Calibration

A central achievement of the PS1 Surveys was the development of an extensive Image Processing Pipeline (IPP) that handles raw data from image acquisition to catalog generation. This pipeline includes stages for detrending, geometric transformation, stacking, and difference imaging—all crucial for producing high-fidelity imaging and photometric data. A rigorous calibration process ensured uniform photometry to a precision of 12 millimags and astrometry accurate to within 20 milliarcseconds relative to the Gaia reference frame.

Data Products and Accessibility

The data products from the PS1 Surveys encompass a variety of image and catalog formats to enable different types of scientific inquiries. Stacked images provide deep integrations over time, while the release of individual epochs supports time-domain studies. The published science products system (PSPS) database offers a relational framework to facilitate access to photometric, astrometric, and transient data, ensuring widespread availability of these data for the scientific community through the Mikulski Archive for Space Telescopes (MAST).

Scientific Outcomes and Implications

The scientific yield of the PS1 Surveys is substantial, spanning multiple domains. One of the highlights includes the surveying of Near Earth Objects, which has not only enhanced the catalog of known bodies but has also provided valuable insights into the population characteristics and orbital dynamics of these objects. The surveys have advanced our understanding of the distribution of stars and galaxies, mapping the structures of the Milky Way and nearby galaxies with unprecedented detail.

The database also supports the paper of variable and transitory phenomena, such as supernovae and other transient events, offering an invaluable resource for follow-up and detailed analysis. Furthermore, the depth and sky coverage of PS1 data provide a critical foundation for future space missions and sky surveys, offering a robust calibration network and reference frame for continued exploration.

Conclusion

The Pan-STARRS1 Surveys represent a formidable advancement in the field of astronomical surveys, delivering rich datasets that continue to drive significant scientific discoveries. The partnership model and innovative design of PS1 serve as a framework to inform subsequent survey operations, setting a benchmark for large-scale astronomical research infrastructures. As data from the Pan-STARRS1 Surveys continue to be exploited, they will undoubtedly contribute to the understanding and exploration of the universe across a wide range of astrophysical contexts.