COSMOS X-ray Group Member Galaxy Catalog Definitions
Overview
The reference for this catalog is George et al. (2011). This is a group membership catalog drawn from the COSMOS ACS galaxy catalog, similar to the one presented in Leauthaud et al. (2007). The main difference between this catalog and the Leauthaud et al 2007 one is that the raw ACS images have now been corrected for the effects of charge transfer inefficiency (CTI, see Massey et al. 2010 for further details). Since the CTI correction scheme slightly changes the noise properties of the raw images, the detections have also changed. For this reason, the GAL_ID field in this catalog can not be used to match to objects in the 2007 catalog. The pixel scale for this catalog is 0.03". To reference this ACS catalog please reference Leauthaud 2007 with updates presented in Leauthaud et al (in prep). This catalog is truncated at F814W (MAG_AUTO) < 24.2 due to the K-band completeness limit for stellar masses and because photoz uncertainties rise near this limit. Objects within ACS masks have also been removed (these are the same masks as in Leauthaud et al. 2007) and a variety of bad detections have been removed ("clean"=1 and "mu_class"=1) as well as galaxies without stellar masses.
The galaxy catalog contains ACS photometric parameters, stellar masses, photoz information, and group membership associations. Please see the README for more details.
| Name | Intype | Units | Description |
|---|---|---|---|
| GAL_ID | long | Galaxy ID number | |
| MAG_AUTO | float | mag | F814W SExtractor magnitude from Leauthaud et al. (2007) |
| ra | double | deg | Right Ascension (J2000) from Leauthaud et al. (2007) |
| dec | double | deg | Declination (J2000) from Leauthaud et al. (2007) |
| SM | float | log(M / Msun) | Stellar mass estimate |
| SM_ERR | float | log(M / Msun) | Uncertainty of SM Error is from model fit and does not include photo-z, photometric, or IMF uncertainties. |
| ZPHOT | float | Photometric redshift from Ilbert et al. (2009). | |
| ZPHOT_ERRLO | float | ZPHOT lower error bar from Ilbert et al. (2009). | |
| ZPHOT_ERRHI | float | ZPHOT upper error bar from Ilbert et al. (2009). | |
| MMGGS | int | Most Massive Group Galaxy within NFW scale radius | |
| P_MEM | float | Membership probability | |
| GROUP_ID | int | Group ID number of most likely group | |
| GROUP_FLAG | int | Group flag (1=good, 0=bad) | |
| DIST_MMGGS | float | R/R200 | Projected distance to MMGGS of GROUP_ID in units of R200 |
| MMGGS_ZBEST | int | MMGGS using GAL_ID's spectroscopic redshift | |
| P_MEM_ZBEST | float | P_MEM using GAL_ID's spectroscopic redshift | |
| GROUP_ID_ZBEST | int | GROUP_ID using GAL_ID's spectroscopic redshift | |
| GROUP_FLAG_ZBEST | int | GROUP_FLAG using GAL_ID's spectroscopic redshift | |
| DIST_MMGGS_ZBEST | float | R/R200 | DIST_MMGGS using GAL_ID's spectroscopic redshift |
| MNUV_MR | float | mag | NUV-R color from Ilbert et al. (2009). |