English

Do minor interactions trigger star formation in galaxy pairs?

Astrophysics of Galaxies 2023-08-25 v2 Cosmology and Nongalactic Astrophysics

Abstract

We analyze the galaxy pairs in a set of volume limited samples from the SDSS to study the effects of minor interactions on the star formation rate (SFR) and colour of galaxies. We carefully design control samples of the isolated galaxies by matching the stellar mass and redshift of the minor pairs. The SFR distributions and colour distributions in the minor pairs differ from their controls at >99%>99\% significance level. We also simultaneously match the control galaxies in stellar mass, redshift and local density to assess the role of the environment. The null hypothesis can be rejected at >99%>99\% confidence level even after matching the environment. Our analysis shows a quenching in the minor pairs where the degree of quenching decreases with the increasing pair separation and plateaus beyond 50 kpc. We also prepare a sample of minor pairs with HαH_{\alpha} line information. We calculate the SFR of these galaxies using the HαH_{\alpha} line and repeat our analysis. We observe a quenching in the HαH_{\alpha} sample too. We find that the majority of the minor pairs are quiescent systems that could be quenched due to minor interactions. Combining data from the Galaxy Zoo and Galaxy Zoo2, we find that only 1%\sim 1\% galaxies have a dominant bulge, 4%7%4\%-7\% galaxies host a bar, and 5%10%5\%-10\% galaxies show the AGN activity in minor pairs. This indicates that the presence of bulge, bar and AGN activity plays an insignificant role in quenching the galaxies in minor pairs. The more massive companion satisfies the criteria for mass quenching in most of the minor pairs. We propose that the stripping and starvation likely caused the quenching in the less massive companion at a later stage of evolution.

Keywords

Cite

@article{arxiv.2207.03968,
  title  = {Do minor interactions trigger star formation in galaxy pairs?},
  author = {Apashanka Das and Biswajit Pandey and Suman Sarkar},
  journal= {arXiv preprint arXiv:2207.03968},
  year   = {2023}
}

Comments

24 pages, 13 figures, 6 tables, significantly revised, main conclusions unchanged, Accepted for publication in Research in Astronomy and Astrophysics. this article supersedes arXiv:2108.05874

R2 v1 2026-06-25T00:45:38.684Z