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The PS1 observations are obtained through a set of five broadband filters, designated as grizyP1. Under certain circumstances PS1 observations are obtained with a sixth, “wide” filter designated as wP1 that essentially spans the gri bands.
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Scolnic, Tonry
- Illustration (plot)
- Compare to other filter systems
- links to filter response functions
Five filters (g, r, i, z, y),are used for PanSTARRS1 (PS1) exposures. This section describes each filter and its characteristics.
Pan-STARRS is primarily sensitive to visible light, though observations extend slightly into the infrared passbands. Each camera included an identical set of 5 to 6 optical filters that can be remotely positioned in front of the focal plane.
The searches for asteroids and potentially hazardous objects may use a wide filter w ("g+r+i") that covers most of the visible waveband from 0.5 to 0.8 microns. This filter provides maximum sensitivity for detecting solar system objects. Surveys for stars and galaxies are much more valuable when they include color information, so Pan-STARRS will include standard photometric g-, r-, i-, and z-band filters, as used in the Sloan Digital Sky Survey. The excellent near-infrared response of the Pan-STARRS detectors means that we can also make use of a y-band filter (1.0 microns). All magnitiudes are quoted on the AB system.
Stubbs photo-diode laser system PS1 measurements: http://adsabs.harvard.edu/abs/2010ApJS..191..376S
Tonry PS1 photometric system: http://adsabs.harvard.edu/abs/2012ApJ...750...99T
Scolnic Supercal: http://adsabs.harvard.edu/abs/2015ApJ...815..117S
for throughput measurement article see: http://inspirehep.net/record/849309/plots
or Ap J Supp: http://iopscience.iop.org/0067-0049/191/2/376/article;jsessionid=A78430B5C673A0619DA938ABD21442C4.c1
The starting point for the PS1 data archive is at Pan-STARRS1 data archive home page.
References
The following information is taken from these papers, which should be cited appropriately
- Chambers et al. 2016, The Pan-STARRS1 Surveys
TJ. Tonry et al. 2012, The Pan-STARRS1 Photometric System
C. Stubbs et al. 2010, Precise Throughput Determination of the PanSTARRS Telescope and the Gigapixel Imager Using a Calibrated Silicon Photodiode and a Tunable Laser: Initial Results
D. Scolnic et al. 2015, Supercal: Cross-calibration of Multiple Photometric Systems to Improve Cosmological Measurements with Type Ia Supernovae
- A link the the overall Pan-STARRS throughputs as shown in the Tonry et al. figure below are here at Vizier or also as a machine readable ascii file here
Filter descriptions
The Pan-STARRS1 observations are obtained through a set of five broadband filters, designated as grizyP1 . Under certain circumstances Pan-STARRS1 observations are obtained with a sixth, “wide” filter designated as wP1 that essentially spans the gri bands. There is full sky 3π sky coverage in each of grizyP1 but not in wP1, which was mostly used for near-earth object surveys. Although the filter system for Pan-STARRS1 has much in common with that used in previous surveys, such as SDSS (York et al. 2000), there are important differences, which is why the filters are labelled specifically with the P1 subscript. The gP1 filter extends 20 nm redward of g-SDSS with the intention of providing greater sensitivity and lower systematics for photometric redshifts. The strong [O I] 5577 sky emission is on the filter edge but only at 1% trans- mission. The zP1 filter has a sharply defined cut-off at 922 nm, which is contrast to the SDSS-z band which is has no red cut off and the response is defined by the detector response. The rP1 and iP1 filters are very similar to SDSS and colour differences between the two magnitude systems are small. SDSS has no corresponding yP1 filter. The transmission of the Pan-STARRS1 filters, optics and total throughout were precisely measured with a calibrated photodiode and a tuneable laser, without use of celestial standards by Stubbs et al. (2010). The definition of the photometric system has already been discussed in detail and published in Tonry et al. (2012b). Photometry is in the “natural” Pan-STARRS1 system in “monochromatic AB magnitudes” (Oke & Gunn 1983) as described in Tonry et al. (2012).
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Figure from Tonry et al. 2012 : The PS1 capture cross-section in m2/e/photon to produce a detected e− for an incident photon for the six Pan-STARRS1 bandpasses, grizy and w for a standard airmass of 1.2 The mean wavelengths are:
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Figure from Scolnic et al. 2015, showing comparisons between the grizP1 and other survey filters (CSP = Carnegie Supernova Project and CfAK = CfA-Keplercam, SNLS = Supernova Legacy Survey |
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Figure from Tonry et al. 2012 : The PS1 capture cross-section in m2/e/photon to produce a detected e− for an incident photon for the six Pan-STARRS1 bandpasses, grizy and w for a standard airmass of 1.2