|The Near-Earth Object Wide-field Infrared Survey Explorer at IPAC
You are strongly encouraged to read the Explanatory Supplement to the NEOWISE Data Release Products before using NEOWISE Image and Source Database information. In particular, please familiarize yourself with the Cautionary Notes sections for the NEOWISE Single-exposure Source Database and NEOWISE Single-exposure Images to make best use of the NEOWISE data products.
The NEOWISE data products are derived from observations made during the NEOWISE Reactivation mission which began surveying in December 2013. These are new observations that are independent from those made during the original WISE mission that ended in February 2011. NEOWISE makes use of the WISE spacecraft to obtain its new 3.4 (W1) and 4.6 (W2) μm images, so the characteristics and sensitivity of NEOWISE data are similar to those from the original WISE mission.
NEOWISE release products include Single-exposure Images and a Source Database from those Images. They do not include deep, coadded Atlas Images or a Source Catalog, such as were produced for the AllWISE, WISE All-Sky and 3-Band Cryo data releases.
Access modes for the NEOWISE image and tabular data products are described in section I.5 of the NEOWISE Explanatory Supplement.
Diameters, optical albedos, near-infrared albedos and beaming parameters for Solar System small bodies derived using measurements made during the first three years of the NEOWISE Reactivation survey are published by Nugent et al. 2015, Nugent et al. 2016 and Masiero et al. 2017. The derived physical parameters for near-Earth and Main Belt asteroids, active Main Belt objects, Hildas, Jupiter Trojans, Centaurs and Jovian and Saturnian irregular satellites from Year 1-3 NEOWISE Reactivation mission, along with those from the WISE 4-Band Cryo, 3-Band Cryo and NEOWISE Post-cryo surveys are available in the NASA Planetary Data System (PDS) Small Bodies Node Asteroid/Dust Archive.
NEOWISE physical parameters taken from the PDS holdings are also reported in search results returned by the JPL Small-Body Database Browser.
The NEOWISE W1 and W2 filter bandpasses are the same as those from the original WISE mission that are described in section IV.4.h.v of the WISE All-Sky Data Release Explanatory Supplement. The filter bandpass relative spectral response (RSR) curves are shown graphically in Figures 4a and 4b in that section, and can be downloaded in ASCII table format from links in the captions to those two figures.
NEOWISE Source Database magnitudes are given in the Vega system and represent total in-band brightness measurements. Conversion of NEOWISE in-band magnitudes to monochromatic values such as flux density or AB magnitude, along with some helpful examples, are described in section IV.4.h.i of the WISE All-Sky Data Release Explanatory Supplement. The broad WISE bandpasses may require applying significant color corrections when deriving monochromatic brightnesses depending on the spectral energy distribution of the particular object. The nominal system flux zero points are defined for a fν∝ν-2 spectrum through the WISE bandpasses. Color corrections for other spectral slopes are given in section IV.4.h.vi of the All-Sky Release Supplement.
NEOWISE Catalog entries have several different photometry measurements available, as described in NEOWISE Supplement section II.1.c.i. The profile-fit magnitudes (w?mpro) and the curve-of-growth corrected "standard" aperture magnitudes (w?mag) systematically underestimate the brightness of sources that are resolved with respect to the NEOWISE PSF. Detections that are spatially associated with known extended sources in the 2MASS Extended Source Catalog (XSC) are identified in the Database by having non-null values of xscprox.
For NEOWISE sources that are associated with 2MASS XSC sources, or that appear extended on the NEOWISE images, you may wish to use the non-curve-of-growth-corrected aperture photometry measurements, w?mag_n (n=1-8).
Yes. Links to gzip'd tar files that contain images of the 9x9 grid of PSFs in each band used for profile-fitting source extraction are in section IV.2.b.i of the NEOWISE Explanatory Supplement.
The NEOWISE Single-exposure Images are designed for relative photometric measurements where the brightness is measured with respect to the local sky background. Pixel values are given in digital numbers (DN), and have not been calibrated in terms of absolute surface brightness. Conversion of relative fluxes in DN to calibrated source magnitudes or fluxes is discussed in II.3.c of the NEOWISE Explanatory Supplement.
The approximate Modified Julian Date of the mid-point of the NEOWISE Single-exposure from which each source detection is drawn is given in the mjd entry of the Source Database.
N.B. - The true observation mid-point times for NEOWISE W1 and W2 detections are slightly earlier than the times given by the mjd value (see I.2.c.iii.1). For source detections made on images acquired before June 23, 2015 11:29:30.47 UTC (mjd=57196.47882488), the observation times are approximately 1.57±0.25sec earlier than the mjd values. For source detections after that date, the observation times are approximately 0.57±0.25 sec earlier than the mjd value.
Last update - 2020 March 25 Contact the WISE/NEOWISE Help Desk