This is the readme for the first data release of the GOODS-Herschel project. A more complete document, a PDF file named GOODS-Herschel_release.pdf, is accompanying this readme. It is very important you read this document as it gives instructions on how to use these data. The PDF file should be found where you got the GOODS-Herschel data, or can be downloaded from the Herschel Database in Marseille (HeDaM).
GOODS-Herschel (Elbaz et al, 2011, A&A, 533, 119) is in ESA open time key project consisting of the deepest Herschel observations of the two Great Observatories Origins Deep Survey (GOODS) fields in the Northern and Southern hemispheres.
The release contains two multi-λ catalogues, one for each field: GOODS-North and GOODS-South.
| Column | Unit | Description |
|---|---|---|
| iau_name | GOODS IAU coded object identifier | |
| id | Sequential id (specific to the catalogue) | |
| ra | deg | Right Ascension |
| dec | deg | Declination |
| f3p6 | µJy | IRAC 3.6 µm flux density |
| err3p6 | µJy | Error on IRAC 3.6 µm flux density |
| flag3p6 | IRAC 3.6 µm source extraction flag (see below) | |
| f4p5 | µJy | IRAC 4.5 µm flux density |
| err4p5 | µJy | IRAC 4.5 µm flux density |
| flag4p5 | IRAC 4.5 µm source extraction flag (see below) | |
| f5p8 | µJy | IRAC 5.8 µm flux density |
| err5p8 | µJy | Error on IRAC 5.8 µm flux density |
| flag5p8 | IRAC 5.8 µm source extraction flag (see below) | |
| f8p0 | µJy | IRAC 8.0 µm flux density |
| err8p0 | µJy | Error on IRAC 8.0 µm flux density |
| flag8p0 | IRAC 8.0 µm source extraction flag (see below) | |
| f24 | µJy | MIPS 24 µm flux density |
| err24_ima | µJy | MIPS 24 µm flux error on residual map |
| err24_sim | µJy | MIPS 24 µm flux error on Monte-Carlo simulations |
| cov24 | MIPS 24 µm coverage map value (equal to sec/pixel) | |
| f70 | µJy | MIPS 70 µm flux density |
| err70_ima | µJy | MIPS 70 µm flux error on residual map |
| err70_sim | µJy | MIPS 70 µm flux error on Monte-Carlo simulations |
| cov70 | MIPS 70 µm coverage map value (equal to sec/pixel) | |
| f100 | µJy | PACS 100 µm flux density |
| err100_ima | µJy | PACS 100 µm flux error on residual map |
| err100_sim | µJy | PACS 100 µm flux error on Monte-Carlo simulations |
| cov100 | PACS 100 µm coverage map value (proportional to sec/pixel) | |
| f160 | µJy | PACS 160 µm flux density |
| err160_ima | µJy | PACS 160 µm flux error on residual map |
| err160_sim | µJy | PACS 160 µm flux error on Monte-Carlo simulations |
| cov160 | PACS 160 µm coverage map value (proportional to sec/pixel) | |
| f250 | µJy | SPIRE 250 µm flux density |
| err250_ima | µJy | SPIRE 250 µm flux error on residual map |
| err250_sim | µJy | SPIRE 250 µm flux error on Monte-Carlo simulations |
| cov250 | SPIRE 250 µm coverage map value (proportional to sec/pixel) | |
| f350 | µJy | SPIRE 350 µm flux density |
| err350_ima | µJy | SPIRE 350 µm flux error on residual map |
| err350_sim | µJy | SPIRE 350 µm flux error on Monte-Carlo simulations |
| cov350 | SPIRE 350 µm coverage map value (proportional to sec/pixel) | |
| f500 | µJy | SPIRE 500 µm flux density |
| err500_ima | µJy | SPIRE 500 µm flux error on residual map |
| err500_sim | µJy | SPIRE 500 µm flux error on Monte-Carlo simulations |
| cov500 | µJy | SPIRE 500 µm coverage map value (proportional to sec/pixel) |
| clean_index | Index measuring flux contamination from nearby sources (see below) |
On GOODS-South, the catalogue has no SPIRE measurements (columns f250 to cov500).
Please, read the GOODS-Herschel release document for a complete description of the two noise estimations: errNNN_ima based on the residual map and errNNN_sim based on Monte-Carlo simulations. In particular, to be conservative, users should always use the highest uncertainty but not the quadratic combination of both since they are not independent. Also, the Monte-Carlo simulations were made on regions with relatively homogeneous exposure time; therefore, uncertainties derived from these simulations are not suitable and hence not provided for sources situated outside these homogeneous exposure time regions.
The IRAC source extraction flag come from the IRAC flag maps as described in the GOODS project DR1 documentation. It's a composite flag based on the values from the table below.
| Flag value | Condition |
|---|---|
| 0 | > 50% of the modal exposure time |
| 1 | < 50% of the modal exposure time |
| 2 | < 20% of the modal exposure time |
| 16 | Region with significant residual muxbleed |
| 64 | No data (zero retained exposure time) |
These values will often appear in combination. For example, regions with < 20% of the modal exposure time (flag value 2) also have < 50% of the modal exposure time (flag value 1). Therefore, those sources will have flag values of 2 + 1 = 3. Regions with no data will have flag values 64 + 2 + 1 = 67. Regions with residual muxbleed (flag 16) and also < 50% modal exposure time (flag 1) will have flag 16 + 1 = 17.
The clean_index measures the flux contamination by nearby sources. It is computed as follows:
Where Neib24 (resp. Neib100, Neib160…) is the number of bright neighbours (see the GOODS-Herschel release document) at 24 µm (resp. 100 µm 160 µm…). On GOODS-South, it is assumed that Neib250 = Neib350 = Neib500 = 0.
For each Herschel filter (PACS100, PACS160, SPIRE250, SPIRE350 and SPIRE500 on GOODS-North; only PACS bands on GOODS-South) we provide three four fits files:
- GH_(field)_(version)_(lambda)_sci.fits: the flux map
- GH_(field)_(version)_(lambda)_err.fits: the error map
- GH_(field)_(version)_(lambda)_cov.fits: the coverage map
- GH_(field)_(version)_(lambda)_psf.fits: the PSF of the map