This page summarizes the data currently available from HSCLA. The current version of HSCLA serves data from PI-based programs taken through 2016 (~3 years). Data from the Subaru Strategic Program are served separately at this site.
All the catalog products have been ingested to the database, and there are various online tools to help you retrieve the data from our server. All of them are described in the Data Access page.
Note that the data products in HSCLA are very similar to those provided at the HSC-SSP data release site. Please be sure to go over the SSP data release paper before using the HSCLA data.
As HSCLA is based on PI-based programs, the field coverage is quite patchy. We split the sky into 48 fields using the simple R.A., and Dec. cuts as shown below. These field IDs can be used to retrieve data in each field from the database (see a sample query available from the SQL editor). The blue regions are observed in at least one filter. The easiest way to find the available filters in each field is to look at the QA plots shown towards the end of this page. The blow-up of each field with tract IDs indicated can be found in the carousel slide below.
The figure shows the total responses of the filters included in HSCLA. The electric version of the responses is available here.
All the catalog products have been loaded to the database, where you can send queries to retrieve data of your interest. There are other data retrieval tools, all of which are described in the Data Access page.
All the flat files from the processing pipelines are also available. Each file is described in the figure on the left. We expect most users are interested in coadd images. They can be found as deepCoadd-results/[filter]/[tract]/[patch]/calexp-[filter]-[tract]-[patch].fits, if you follow the file tree. You can also use a file search tool for bulk download.
Details of the other files can be found below.
ICSRC: Catalog of bright sources detected and measured on a CCD, and used in astrometric and photometric calibration. (FITS BINTABLE)
SRC: Catalog of sources detected and measured on a CCD, output from the final stage of the single frame processing. See CALSRC, too. (FITS BINTABLE)
SRCMATCH: Source catalog (SRC) cross-matched with the external reference (PS1) sources. Identification numbers and separation angles in cross-matching are recorded for the external sources. (FITS BINTABLE)
SRCMATCHFULL: Another form of SRCMATCH, in which coordinates and fluxes of the external sources are explicitly listed (de-normalized) rather than listing the identification numbers only. (FITS BINTABLE)
CORR: CCD image with calibrated coordinates and magnitude zeropoint from the single frame processing. See CALEXP, too. (Muliti-extension FITS IMAGE + BINTABLE)
BKGD: Sky background model subtracted from a CCD image. (Multi-extension FITS IMAGE)
skyCorr: Residual pattern to be subtracted from a CORR image to get the global sky subtraction applied. (Multi-extension FITS IMAGE)
jointcal_wcs: Astrometric calibration from jointcal estimated using all CCDs in multiple visits of the same field. (FITS BINTABLE)
jointcal_photoCalib: Photometric calibration from jointcal using all CCDs in mutiple visits of the same field. (FITS BINTABLE)
det: List of source positions and footprints detected on a coadd patch. (FITS BINTABLE)
det_bkgd: Constant background subtracted in the object detection phase.
warp: Image of a single visit (CORR) transformed onto a destination tangential plane in a tract. (Multi-extension FITS IMAGE + BINTABLE)
psfMatchedWarp: warp image convolved to a common seeing. (Multi-extension FITS IMAGE + BINTABLE)
calexp: Coadd image in a single band, or resultant image from the Stack stage, which combines all the overlapped warp images. (Multi-extension FITS IMAGE + BINTABLE)
$(patch)_nImage: Image representing a number of visits contributed to each pixel in coaddition. (Multi-extension FITS Image)
$(patch): Coadd image in a single band right after the coaddition and before the source detection stage, in which sky background is slightly updated. (Multi-extension FITS IMAGE + BINTABLE)
mergeDet: Merged list of source positions and footprints from all filters in a coadd patch. (FITS BINTABLE)
meas: Single-band source catalog measured on each of sources in a coadd image listed in mergeDet. Peak positions and shapes of sources are determined in a band being measured. (FITS BINTABLE)
srcMatch: Single-band source catalog (meas) cross-matched with the external reference (PS1) sources. (FITS BINTABLE)
srcMatchFull: Another form of srcMatch. Coordinates and fluxes of the external sources are explicitly listed (de-normalized) in the same manner as in SRCMATCHFULL. (FITS BINTABLE)
ref: List of source positions and shapes determined by merging results of the single-band measurements (meas) in a coadd. Reference catalog used for the final forced measurement. (FITS BINTABLE)
forced_src: Source catalog from a multi-band measurement, which is performed on each of sources listed in the ref catalog. Positions and shapes are held fixed in the reference band in the measurements. Final catalog from the forced photometry. (FITS BINTABLE)
We have performed a number of quality assurance tests. These are identical tests to those performed for the SSP data (refer to this paper for details), but in short, figures show
(1) tract IDs
(2) astrometric accuracy in R.A. with respect to Gaia using bright point sources
(3) astrometric accuracy in Dec. with respect to Gaia using bright point sources
(4) seeing distribution
(5) 5sigma depth for point sources
(6) difference between Kron and PSF photometry for bright point sources
(7) difference between CModel and PSF photometry for bright point sources
(8) PSF size residual between model and observed PSF
(9) difference between HSC and PS1 photometry for bright point sources
(10) rms scatter between HSC and PS1 photometry for bright point sources
The first figure will be useful to identify tract numbers in your fields of interest, and figures 4 and 5 will give you a sense for the data quality. Figs 6-8 are internal consistency checks and Figs 9-10 are external consistency checks. We encourage you to look at their fields of interest for exploiting the data for science.
As targets from PI programs vary significantly, the pipeline processing did not result in the most optimal reduction in some cases. This is particularly the case where the target is a nearby galaxy or a very extended object (the pipeline is optimized for blank field data for now). We do not flag them here as it is a fundamental limitation of the pipeline, but the user should be cautious when using the following tracts as they could be affected. There are other problems; some fields suffer from nearby bright stars, poor sky subtraction, etc. See below for details.
|9451,9452||NB387||Residual background due perhaps to bad sky frame used in the processing.|
|12954, 12955, 13180||NB656||Bad background subtraction due perhaps to bad sky frame used in the processing.|
|14945. 15142||NB515||Background subtraction error?|
|15788, 15789, 15967, 15968||NB515||Processing failure.|
|7083, 7319||y||Bad sky subtraction.|
|7194, 7430, 7431||y||Bad sky subtraction.|
|8004-8006, 8244-8246, 8485-8488, 8727-8730||y||Scattered light.|
|14134, 15134, 14345, 14346||i||Astrometric calibration failure.|
|4204, 4205||gi||Processing failure|
|7556, 7557, 7782, 7783, 7795, 7796, 7801, 8022, 8023, 8041, 8286, 8287, 8499, 8259, 8986, 9006, 9007, 9737, 9952, 9953, 9979, 9980, 9946, 9947, 10188, 10189, 10194, 10195, 11149, 11150, 11154, 11155, 11167-11169, 11406-11408, 11643-11645, 12132, 12133, 12327, 12328, 12332, 12333, 12624, 13274, 13275, 13464, 13465, 14531, 15398, 15331, 16315, 16316, 16481, 16482, 16641-16644, 16798, 16799||i||Scattered light.|
|6732, 6733, 6995, 6996, 7230, 7231, 7467, 7468, 7706, 7707, 7708, 7945, 7946, 7947, 8185, 8186, 8187, 8427, 8428, 8668, 8669, 8670, 11772, 11773, 12007, 12008||r||Bad background subtraction due to bad sky frame used in the processing.|
|10047, 10048||r||Bad sky subtraction.|
|9583-9585, 9825-9827, 10067-10069, 10310-10314, 10548, 10789-10791, 12433-12436, 12664-12666, 12892-12894||r||Scattered light|
|9959, 10201||r||Astrometric calibration failure.|
|5695, 5696, 5919, 5920, 9852, 10094||g||Background issue|
As we use the same processing pipeline as the the HSC-SSP public data release, the HSCLA data have the same issues as HSC-SSP. We choose to centralize the issue list at the HSC-SSP website. Please refer to this page. If you discover a new issue, please report to us.