- Find luminosity function of galaxies in the Local Volume with distances less than 10Mpc.
- Number-density profile of galaxies around massive galaxies in the catalog. Find 4 largest galaxies in the sample excluding our Galaxy and Andromeda. For each large galaxy, find how many other galaxies are within 500kpc distance. Find the number density of those galaxies dN/dV and average over the four large galaxies to find
as a function of distance from the central galaxy R. What is the shape of the number-density profile? Does it decline with the distance? Does the NFW profile provide a good approximation for the profile? - How large are the deviations of line-of-sight velocities from the Hubble flow? Each galaxy in the catalog has radial velocity relative to the Local Group V_gal and the distance to the galaxy R. Deviation from the Hubble flow is dV =V_gal -HR, where the Hubble constant H=70 km/s/Mpc. How large are those deviations? Use the rms deviations (dV**2)**1/2. Study dependance of deviations as a function of absolute magnitude of galaxies and a function of distance from the Local Group.
SDSS catalog
- What is the fraction of spirals and ellipticals in the SDSS sample? Select galaxies in the redshift range z=0.07-0.15. How does the fraction of ellipticals change for galaxies with different absolute magnitude in 'r' band? How does the fraction change if instead of 'r' magnitude we use 'u'?
- What is the fraction of spirals/ellipticals as a function of environment? Select galaxies in the redshift range z=0.07-0.15. Take all galaxies M_r<-20. We define 'environment' as the number of galaxies with absolute magnitude M_r brighter than -20 within projected distance 1 Mpc and +/-3Mpc along the line of sight.
Clusters of Galaxies in SDSS catalog
References: Abdullah etal 2019, 2020
Data: List of clusters List of galaxies
For cluster radii use quantities with overdensity 200 : columns 14-20
- How does the morphological type of galaxies in clusters depends on the distance from the cluster center? Split the sample of clusters by mass and study the ratio ellipticals to the total number of galaxies as a function of cluster-center distance.
- Find (a) the cluster mass function, (b) distribution of cluster radii, (c) cluster velocity function. Use only clusters with distances in the range 100-400 Mpc. Cluster velocity function is the number-density of clusters dN/dVrms/Volume with given rms velocity of galaxies Vrms
- Projected number-density profiles of galaxies in clusters of different mass. Are they approximated by the NFW profiles?