Local_Universe.GalGroup_Bayes table
The GalGroup_Bayes table contains data on galaxy groups/clusters that were found with Bayesian group finder based on marked/object point processes. The group/cluster identification numbers, groupid
, are independent from id numbers in the GalGroup_2MRS and GalGroup_Comb tables.
Table structure
Column | Type | UCD | Unit | Description |
---|---|---|---|---|
groupid | int | meta.id meta.main | group/cluster identification number | |
ngal | int | meta.number | richness (number of members) of the group | |
raj2000 | double | pos.eq.ra | deg | right ascension of the group centre |
dej2000 | double | pos.eq.dec | deg | declination of the group centre |
glon | double | pos.galactic.lon | deg | galactic longitude of the group centre |
glat | double | pos.galactic.lat | deg | galactic latitude of the group centre |
sglon | double | pos.supergalactic.lon | deg | supergalactic longitude of the group centre |
sglat | double | pos.supergalactic.lat | deg | supergalactic latitude of the group centre |
zcmb | double | src.redshift | CMB-corrected redshift of group, calculated as an average over all group/cluster members | |
groupdist | double | pos.distance | Mpc | comoving distance to the group centre |
sigma_v | float | stat.stdev phys.veloc | km/s | rms radial velocity deviation (sigma_v in physical coordinates) |
sigma_sky | float | stat.stdev pos.distance | Mpc | rms deviation of the projected distance in the sky from the group centre (sigma_sky in physical coordinates); sigma_sky defines the extent of the group in the sky |
r_max | float | stat.max phys.size.radius | Mpc | distance from group centre to the farthest group member in the plane of the sky |
mass_200 | float | phys.mass | 10+12Msun | estimated mass of the group assuming the NFW density profile |
r_200 | float | phys.size.radius | kpc | radius of the sphere in which the mean density of the group is 200 times higher than the average of the Universe |
x_sg | double | pos.cartesian.x | Mpc | supergalactic Cartesian coordinate along the x-axis |
y_sg | double | pos.cartesian.y | Mpc | supergalactic Cartesian coordinate along the y-axis |
z_sg | double | pos.cartesian.z | Mpc | supergalactic Cartesian coordinate along the z-axis |
Sample queries
- Select all columns for a specific group, based on the ID number
groupid
:SELECT * FROM Local_Universe.GalGroup_Bayes WHERE groupid=123
- Select all groups that have at least 5 galaxies:
SELECT * FROM Local_Universe.GalGroup_Bayes WHERE ngal>=5