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Register a new userA mechanism to explain Galaxy alignment over a range of scales
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Added by
Prabhakar Tiwari Dr.
Publication date
2021
fields
Physics
and research's language is
English
Authors
Prabhakar Tiwari
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The observed large-scale alignment of polarization angles and galaxy axis have been challenging the fundamental assumption of homogeneity and isotropy in standard cosmology since more than two decades. The intergalactic magnetic field, and its correlations in real space, potentially seems as a viable candidate for explaining this phenomenon. It has been shown earlier that the large-scale intergalactic magnetic field correlations can explain the alignment signal of quasars over Gpc scale, interestingly they can also explain the radio polarization alignment observed in JVAS/CLASS data over 100 Mpc. Motivated with recent observations of galaxy axis alignment over several tens of Mpc, and Mpc scale, i.e., the cluster scale, we further explore the correlations of background magnetic field to explain these relatively small scale alignment observations. In particular, we explore two recently claimed signals of alignment in the radio sources in the FIRST catalog and in the ACO clusters. We find that both of these can be explained in terms of the intergalactic magnetic field with a spectral index of $-2.62pm 0.03$. The large-scale magnetic field correlations potentially seem to explain the polarization and galaxy axis alignment from Gpc to Mpc scales.
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This paper has been withdrawn. I belatedly found that the alignment I saw in galaxy cluster axes was bogus. It turns out that it is due to a well-known effect called the Fingers of God that stretches out the redshifts of galaxies in a cluster due to their motion within the cluster. This would not cause an overall bias if the SDSS survey were complete, but there is no coverage toward right ascensions near 90 degrees or 270 deg. Thus the apparent alignment appears along 0 -- 180 deg.
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