CosmoDB

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

1. Select all columns for a specific group, based on the ID number groupid:

   SELECT * FROM Local_Universe.GalGroup_Bayes WHERE groupid=123

2. Select all groups that have at least 5 galaxies:

   SELECT * FROM Local_Universe.GalGroup_Bayes WHERE ngal>=5