SDSS data for dipole/quadrupole in galaxy spin in a dataset of low redshift objects
For code and data for the reproduction of the experiment of (Iye et al., 2021) click here.
This page provides data files of SDSS galaxies used in the experiment described in Shamir, L., Using 3D and 2D analysis for analyzing large-scale asymmetry in galaxy spin directions, In Press.
That is also the exact same 'clean' dataset used in Masanori Iye , Masafumi Yagi, Hideya Fukumoto, 2021, AJ, Spin Parity of Spiral Galaxies. III. Dipole Analysis of the Distribution of SDSS Spirals with 3D Random Walk Simulations.
The catalog inludes the RA, Dec of the objects and the spin direction (cw/ccw). It also provides the number of galaxies with opposite spin directions in opposite hemispheres centered at RA=160 degrees.
Code for reproducing the analysis of dipole axis in galaxy spin directions as done by (Iye et al., 2021) is available here.
Important note: The dataset used in (Iye et al., 2021) was taken from (Shamir, 2017, PASA). That paper does not make any attempt to show any kind of axis in that dataset. No claim for an axis in that dataset was made in any of my other papers. All of my papers cited in (Iye et al., 2021) as papers that showed a dipole axis used other datasets, and not the one used in (Iye et al., 2021).
The dataset used in (Shamir, 2017, PASA) is a dataset of bright objects (i<18) and therefore, on average, lower redshift. Previous work showed lower asymmetry in lower redshift ranges. The dataset also uses a minimum of 10 peaks in the radial intensity plot to make an annotation, rather than 30 peaks in the papers showing a dipole axis. The minimu of 30 peaks leads to cleaer annotations, and the imperfect annotation when using 10 peaks is discussed in (Shamir, 2017, PASA). Still, the distribution in the dataset is not random, as shown here.
Shamir, L., Using 3D and 2D analysis for analyzing large-scale asymmetry in galaxy spin directions, In Press.