COSMOS-Web DR1 HST mosaics
COSMOS-Web: HST ACS F814W mosaics
Authors: A. M. Koekemoer et al.
The COSMOS-Web DR1 HST mosaics can be downloaded using the following links. This page provides a description of the data products, which are based on an updated version of the original COSMOS HST ACS F814w imaging data first presented in Koekemoer et al. (2007).
Description
For this project, the original COSMOS HST ACS F814W imaging data (Koekemoer et al. 2007) was recalibrated using hstcal version 2.7.4 and HST CRDS 11.14.0, and in addition was astrometrically aligned directly to Gaia-DR3 (Gaia collaboration et al. 2021) and the COSMOS2020 catalogue (Weaver et al. 2022), providing r.m.s. ~0.01" absolute astrometric accuracy.
Please always cite Koekemoer et al. (2007) when referring to the COSMOS HST ACS F814W imaging data.
The field has been divided into 20 tiles pictured below:
Table of tile corners (click to expand)
| Tile | Corner 1 (RA, Dec) | Corner 2 (RA, Dec) | Corner 3 (RA, Dec) | Corner 4 (RA, Dec) |
|---|---|---|---|---|
| A1 | 149.8703317 2.0856512 | 149.7198796 2.1403395 | 149.7908786 2.3354095 | 149.9413496 2.2807163 |
| A2 | 150.0058959 2.0363591 | 149.8554506 2.0910612 | 149.9264667 2.2861269 | 150.0769300 2.2314186 |
| A3 | 150.1414523 1.9870553 | 149.9910155 2.0417704 | 150.0620479 2.2368306 | 150.2125019 2.1821081 |
| A4 | 150.2769995 1.9377408 | 150.1265729 1.9924679 | 150.1976208 2.1875215 | 150.3480637 2.1327859 |
| A5 | 150.4125359 1.8884166 | 150.2621212 1.9431545 | 150.3331838 2.1382005 | 150.4836139 2.0834528 |
| A6 | 149.8045087 1.9048087 | 149.6540746 1.9594923 | 149.7250552 2.1545612 | 149.8755087 2.0998725 |
| A7 | 149.9400575 1.8555218 | 149.7896293 1.9102182 | 149.8606274 2.1052826 | 150.0110740 2.0505800 |
| A8 | 150.0755992 1.8062243 | 149.9251788 1.8609325 | 149.9961935 2.0559913 | 150.1466316 2.0012757 |
| A9 | 150.2111325 1.7569171 | 150.0607214 1.8116361 | 150.1317520 2.0066883 | 150.2821799 1.9519607 |
| A10 | 150.3466557 1.7076011 | 150.1962556 1.7623299 | 150.2673014 1.9573744 | 150.4177173 1.9026358 |
| B1 | 150.0020274 2.4473359 | 149.8515406 2.5020333 | 149.9225757 2.6970916 | 150.0730806 2.6423895 |
| B2 | 150.1376214 2.3980335 | 149.9871430 2.4527469 | 150.0581944 2.6478011 | 150.2086900 2.5930817 |
| B3 | 150.2732061 2.3487174 | 150.1227378 2.4034461 | 150.1938048 2.5984949 | 150.3442894 2.5437590 |
| B4 | 150.4087801 2.2993886 | 150.2583236 2.3541315 | 150.3294054 2.5491739 | 150.4798772 2.4944226 |
| B5 | 150.5443418 2.2500480 | 150.3938989 2.3048040 | 150.4649946 2.4998389 | 150.6154520 2.4450733 |
| B6 | 149.9361713 2.2664951 | 149.7857017 2.3211879 | 149.8567188 2.5162544 | 150.0072070 2.4615567 |
| B7 | 150.0717506 2.2171978 | 149.9212885 2.2719056 | 149.9923224 2.4669678 | 150.1428020 2.4122539 |
| B8 | 150.2073213 2.1678878 | 150.0568686 2.2226097 | 150.1279183 2.4176665 | 150.2783878 2.3629373 |
| B9 | 150.3428821 2.1185662 | 150.1924404 2.1733011 | 150.2635052 2.3683514 | 150.4139629 2.3136080 |
| B10 | 150.4784314 2.0692337 | 150.3280023 2.1239807 | 150.3990815 2.3190234 | 150.5495255 2.2642668 |
All tiles are drizzled with the same tangent point:
CRVAL1 = 150.1163213
CRVAL2 = 2.200973097Names of the files are:
mosaic_acs_{filter}_COSMOS-Web_{pixel_scale}_{tile}_v1.0_{ext}.fitswhere filter is the F814W filter that was used to image this field with HST ACS. Mosaics are provided at two different pixel_scales, given by the pixel_scale keyword, either 30mas or 60mas. The mosaics are provided as separate files indicated by ext corresponding to sci, err, and wht, with the properties of these files being as follows:
Ext DataType Type of file
SCI float32 Science pixels, units e/s
ERR float32 rms, all noise terms, units e/s
WHT float32 inverse variance, background noise, units 1/(e/s)^2To facilitate the handling of these data, all the files have been compressed since they are quite large, with the compressed sizes at ~1.6-1.7 Gb for the 30mas mosaic files, and ~0.4 Gb for the 60 mas mosaic files.
Downloads
Tarballs of all tiles
30mas pixel scale
| Extension | F814W |
|---|---|
sci |
F814W (33 Gb) |
err |
F814W (30 Gb) |
wht |
F814W (30 Gb) |
60mas pixel scale
| Extension | F814W |
|---|---|
sci |
F814W (8.3 Gb) |
err |
F814W (7.6 Gb) |
wht |
F814W (7.6 Gb) |
Individual tiles
30mas pixel scale
These files are typically ~1.6-1.7 Gb each (compressed).
| Tile | F814W |
|---|---|
| A1 | sci err wht |
| A2 | sci err wht |
| A3 | sci err wht |
| A4 | sci err wht |
| A5 | sci err wht |
| A6 | sci err wht |
| A7 | sci err wht |
| A8 | sci err wht |
| A9 | sci err wht |
| A10 | sci err wht |
| B1 | sci err wht |
| B2 | sci err wht |
| B3 | sci err wht |
| B4 | sci err wht |
| B5 | sci err wht |
| B6 | sci err wht |
| B7 | sci err wht |
| B8 | sci err wht |
| B9 | sci err wht |
| B10 | sci err wht |
60mas pixel scale
These files are typically ~0.4 Gb each (compressed).
| Tile | F814W |
|---|---|
| A1 | sci err wht |
| A2 | sci err wht |
| A3 | sci err wht |
| A4 | sci err wht |
| A5 | sci err wht |
| A6 | sci err wht |
| A7 | sci err wht |
| A8 | sci err wht |
| A9 | sci err wht |
| A10 | sci err wht |
| B1 | sci err wht |
| B2 | sci err wht |
| B3 | sci err wht |
| B4 | sci err wht |
| B5 | sci err wht |
| B6 | sci err wht |
| B7 | sci err wht |
| B8 | sci err wht |
| B9 | sci err wht |
| B10 | sci err wht |