A few "typical" Galaxies from the Sloan Survey

3. A few "typical" Galaxies from the Sloan Survey

5. The SDSS sky coverage is, of course, far from complete. (A) Polar plot of right ascensions vs. redshifts for all declinations (B) Plot of declinations vs. redshifts. The left and right hemispheres in (A) are plotted on their respective sides in (B). Declinations between -19° and +60° were used in this analysis.

6. The Analysis (1) First select galaxies from the SDSS with the SQL command: select p.objid, p.ra, p.dec, p.u, p.g, p.r, p.i, p.z, s.z as redshift from galaxy p, specobj s where p.objid=s.bestobjid and p.g < 17 and s.z BETWEEN 0.001 AND .04 which translates as "Select galaxies (with spectra) with green magnitude <17 and with redshifts between 0.001 and 0.04." This yielded 22,768 galaxies.

7. The Analysis (2) These were then scanned "by hand" and galaxies with fairly clear spiral structure were selected. No Yes NoNo Galaxies that were seen too "edge-on" for spiral structure to be apparent were not used. No

8. The Analysis (2-cont'd) This scanning was done randomly in right ascension and declination, so that any bias would not give a false signal. Selected spirals were scaled appropriately and down-loaded from the SDSS web site as JPEG files for further analysis. Each JPEG had separate red, green, and blue images. After some months of effort, this yielded approx. 2835 spirals.

9. The Analysis (3) The spiral candidates were then analyzed by an IDL program to determine their handedness. The red, green, and blue components of the JPEG files were analyzed separately. "Right-handed" The conventions for right- and left-handed spirals are shown. "Left-handed"

11. I spent many months experimenting with different spiral masks to find the best shape. The diversity of galactic shapes and peculiari-ties is daunting. I varied many parameters including the pitch of the spiral, its width, theweighting vs. radius, and the possibility of a central bar, as well as the use of multiple masks. Each of these was tested against a random sample of galaxies whose handedness was determined "by hand". In the end a rather simple mask turned out to be as good as any, and it had the very distinct advantage that the mirror image was generated by changing one sign in the term describing its pitch. This made the possibility of some built-in asymmetry extremely unlikely. This was my main concern. A more complicated mask or a combination of several masks might have increased the efficiency in finding spirals slightly at the expense of greater complication and the increased possibility of a subtle flaw. In the end, the efficiency of the mask can only be judged by comparing it with "eyeball" determinations of the handedness. Judging by eye, the mask used was probably >95% efficient for 2-arm spirals and ~85% for multi-arm ones.

13. Fourier Power vs. Order for previous example Fourier Power vs. Order Red is positive handedness mask Blue is negative

14. Spiral galaxies that have recently been disrupted by collisions or close encounters with other galaxies are likely to have lost their primordial spin orientation. These tend to be blueish due to new star formation, while old, sedate spirals are more yellowish. A selection on the spectrum requiring 1.9 < |U-Z| <3.7 was made to remove the bluest ones. Here U is the magnitude in the ultraviolet band and Z is the far infrared.

15. Red are positive spins; blue are negative. There seems to be some patchy structure, but hard to tell.

16. Net asymmetries <A> by sector in RA and segments in z. Segments with positive <A> are indicated in red and negative <A> in blue. The <A> for segments with <10 galaxies are not shown. The larger numbers near the periphery give the overall asymmetry for that sector; the black num- bers in parentheses are the total number of spiral galaxies in the sector.

17. The s are determined from standard normal distribution statistics, , which gives The 3rd row shows the difference in number counts between the first two rows. The combined asymmetry differs from zero by 2.89 s . The nominal probability for exceeding 2.89 s is 0.39%.

20. Quadrupole

21. Octupole

22. Several anomalous features in the WMAP data have been reported, pointing toward a preferred direction in the sky, the so-called "axis of evil." The origin of this effect remains mysterious, and it could well be that it is due to foreground contamination or unsubtracted systematic errors. Unlike point reflections, mirror reflections select a preferred direction in the sky, that of the normal to the symmetry plane. Hence the search for mirror handedness entails the search for a preferred axis in the CMB fluctuations (although the converse need not be true). The first purpose of this paper is to investigate whether mirror parity could shed light upon the observed statistical anisotropy of CMB fluctuations.

25. D. Huterer – "Mysteries of the Large-Angle Microwave Sky"

27. Campanelli et al., cont'd

28. Campanelli et al. suggest that the eccentricity is produced by a cosmic magnetic field ~5 x 10-9 G. * This model can also account for the alignment of the dipole with the "axis of Evil", if we tweak it a bit. All we need is to allow a small asymmetry between the poles of the ellipsoid. The conventional wisdom is that the dipole is associated with our motion through the rest system of the CMB. However, a flattened ellipse could easily produce a dipole term which overwhelms that due to our motion. _________________ * Earlier suggested by Ya. Zeldovich, 1965, Zh. Eksperim. I Teor. Fiz 48, 986.

29. A "uniform" primordial cosmic magnetic field would naturally lead to a handedness in the orientation of spiral galaxies. Matter condensing from primordial cosmic plasma would spiral around the magnetic field lines, losing energy and eventually forming spiral galaxies, whose handedness axis is along the direction of the magnetic field and the direction of the normal to the plane defined by the quadrupole axes. My interpretation of all this is that there is indeed a large-scale cosmic magnetic field that extends at least out to distance scales corresponding to the last scattering surface, ~100,000 yrs after the Big Bang. This explains the spiral galaxy spin axis, the CMB quadrupole (and maybe dipole) orientations, and probably the other peculiarities of the low-ℓ moments of the CMB. [It, of course, can't explain the alignment with the equinoxes!]

30. When I first saw the apparent spin alignment of the spiral galaxies, I thought that if was fortuitous that the axis of the alignment was so well lined up with the axis about which the Sloan Survey covered. However, it turns out this seems not to be a matter of luck at all! Astro-nomical surveys prefer to look along the poles of our Galaxy where the Milky Way and dust don't interfere. The North Galactic Pole is at RA =192.9°,  = 27.1°, which is right along the axis of the asymmetry. Furthermore, the handedness (direction) of our Galaxy is aligned in the same direction as the preferred spin alignment (right-handed as seen from the direction of the North Galactic Pole).

31. Our Galaxy as seen from the NGP. Our Galaxy is apparently oriented with the same spin direction as the majority of the spirals, i.e., right-handed as seen from RA ~180°.

32. NGP We can't say too much about the agree- ment of all these axes in declination. As explained previously, all lie near the North Galactic Pole, including the region covered by the Sloan Survey. NGP

33. In summary, the spiral galaxy spin alignment seems to coincide within an uncertainty ~10° with: • The normal to the 2 quadrupole axes • Two of the octopole axes • The dipole axes (which is supposed to be due to Sun's motion through rest system of the microwave background). • The North Galactic pole and the coverage of the astronomical surveys. • The general direction of the dark matter filaments in the COSMOS analysis (generally along RA=150°, =2.3°). The thing I can't explain-- • The ecliptic (plane of the Earth around the Sun) and the equinoxes.