The DEEP3 redshift catalog includes a new tag, not contained in the DEEP2 redshift catalog. This tag is EGSFLAGS, which provides information about which objects belong to which input target list — unlike DEEP2, which was optically-selected to be R < 24.1, DEEP3 is targeting a variety of sources pulled from a variety of target lists. The table below shows the breakdown of the flag values (and associated target lists). Note that the targeting rates listed are approximate and that they varied from survey to survey both due to varying target priorities and varying coverage (e.g. many Chandra sources fell at the ends of the slitmasks and thus didn’t get an equal chance to be assigned a slit).
The EGSFLAGS value is a LONG integer value, containing the bitwise OR of all of the flag values pertaining to an object. Many objects will have been eligible for targeting based on multiple reasons (e.g. a source might be both a “FIDEL 24um priority 1” source and a “DEEP2 previously untargeted” object). In such cases, all of the relevant flags are set — for example, a Chandra source which is also a power-law AGN candidate will have both the 2^4 and 2^10 bits set.
To test if a given bit is set (e.g. bit 2^5), you can use the following code in IDL:
IDL> zcat = mrdfits(‘zcat.egs.fits.gz’, 1)
IDL> isbit5set = (zcat.egsflags AND 2L^5b) ne 0
If isbit5set is 1, then the bit is set. If it is 0, then it is not.
| EGSFLAGS Value | Target Sample | Number in DEEP3 Area | Number Selected | Fraction Selected |
| 2^0 | FIDEL 70um priority 1 | 335 | 294 | 0.878 |
| 2^1 | FIDEL 70um priority 2 | 394 | 74 | 0.188 |
| 2^2 | FIDEL 24um priority 1 | 129 | 120 | 0.930 |
| 2^3 | FIDEL 24um priority 2 | 20 | 18 | 0.900 |
| 2^4 | Chandra | 208 | 154 | 0.740 |
| 2^5 | C. Conselice’s massive galaxies | 441 | 267 | 0.605 |
| 2^6 | R. Ivison’s 20cm sources | 125 | 97 | 0.776 |
| 2^7 | M. Im’s bright 15um sources | 65 | 61 | 0.938 |
| 2^8 | M. Im’s faint 15um sources | 91 | 45 | 0.495 |
| 2^9 | J. Huang’s IRS sources | 4 | 3 | 0.750 |
| 2^10 | S. Park’s power-law AGN | 80 | 57 | 0.712 |
| 2^11 | S. Willner’s 6cm sources | 90 | 77 | 0.856 |
| 2^12 | D. Rosario’s IRAC AGN | 30 | 30 | 1.000 |
| 2^13 | Moustakas/Dutton lenses | 3 | 3 | 1.000 |
| 2^14 | C. Willmer’s IRS object | 0 | 0 | 0.000 |
| 2^15 | B. Gerke’s dual-AGN | 7 | 7 | 1.000 |
| 2^16 | DEEP2 – prev. untargeted | 7454 | 4609 | 0.618 |
| 2^17 | DEEP2 – prev. targeted | 2596 | 1221 | 0.471 |
| 2^18 | faint extension (CFHTLS) | 30,868 | 1488 | 0.048 |
| 2^19 | DEEP2 lens reobservations | 12 | 12 | 1.000 |
| 2^20 | SNLS SN hosts – high priority | 3 | 1 | 0.333 |
| 2^21 | SNLS SN hosts – low priority | 42 | 31 | 0.738 |
| 2^22 | new (2009) AEGIS-X sources | … | … | … |
| 2^23 | yet newer (2010) AEGIS-X sources | … | … | … |
| 2^24 | H. Yan’s high-z candidates | … | … | … |