Effect of galaxy mergers on dust masses
Abstract
Dust mass (MDust) is one of the key physical properties of galaxies that track the cold interstellar medium. However, the MDust in merging galaxies is poorly understood. We aim to derive how the cold dust mass of galaxies is affected by major mergers at low redshifts. MDust was estimated for approximately 500 major mergers in the North Ecliptic Pole extragalactic field using spectral energy distribution fitting runs with CIGALE, with different dust attenuation and emission models. We also analysed over 12 000 mergers from the SIMBA simulation using its MDust. We matched merging and non-merging systems in stellar mass, redshift, and local density, to enable a comparison of MDust. We then performed a second comparison using a control sample also matched in SFR. AGN host galaxies were then removed, and this matching repeated. Observed mergers have larger MDust than the non-mergers by up to a factor of 1.82±0.35, or 1.60±0.44 without AGN-hosts. When matched by SFR, observed mergers show no significant change in MDust, both when including and excluding AGN-hosts. SIMBA galaxies show similar trends when AGN-hosts are included but there is still an increase in MDust when matched by SFR. When AGN-hosts are excluded, the SIMBA mergers show smaller MDust by a factor of 0.98±0.03, or 0.97±0.02 when matched in SFR. The higher the mass of a merger, the greater MDust increase for observations for two of the CIGALE runs, or the smaller the decrease for SIMBA. Observed mergers are typically more dusty than their non-merging counterparts but only because they typically have higher SFRs, regardless of whether they host AGN or not. SIMBA mergers follow observations when AGN hosts are included, but show reduced MDust when AGN hosts are removed. MDust in SIMBA is linked to AGN in a way not seen in observations.
Related
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BibTeX
@misc{pearson2026effect,
title = {{Effect of galaxy mergers on dust masses}},
author = {W. J. Pearson and M. Romano and K. Małek and D. Donevski and K. Lisiecki and A. P. Cotter and S. Dey and T. Goto and S. C. -C. Ho and D. J. Santos},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26166},
eprint = {2610.26166},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26166},
}
RIS
TY - UNPB
TI - Effect of galaxy mergers on dust masses
AU - W. J. Pearson
AU - M. Romano
AU - K. Małek
AU - D. Donevski
AU - K. Lisiecki
AU - A. P. Cotter
AU - S. Dey
AU - T. Goto
AU - S. C. -C. Ho
AU - D. J. Santos
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26166
UR - https://arxiv.org/abs/2610.26166
AB - Dust mass (M_Dust) is one of the key physical properties of galaxies that track the cold interstellar medium. However, the M_Dust in merging galaxies is poorly understood. We aim to derive how the cold dust mass of galaxies is affected by major mergers at low redshifts. M_Dust was estimated for approximately 500 major mergers in the North Ecliptic Pole extragalactic field using spectral energy distribution fitting runs with CIGALE, with different dust attenuation and emission models. We also analysed over 12 000 mergers from the SIMBA simulation using its M_Dust. We matched merging and non-merging systems in stellar mass, redshift, and local density, to enable a comparison of M_Dust. We then performed a second comparison using a control sample also matched in SFR. AGN host galaxies were then removed, and this matching repeated. Observed mergers have larger M_Dust than the non-mergers by up to a factor of 1.82±0.35, or 1.60±0.44 without AGN-hosts. When matched by SFR, observed mergers show no significant change in M_Dust, both when including and excluding AGN-hosts. SIMBA galaxies show similar trends when AGN-hosts are included but there is still an increase in M_Dust when matched by SFR. When AGN-hosts are excluded, the SIMBA mergers show smaller M_Dust by a factor of 0.98±0.03, or 0.97±0.02 when matched in SFR. The higher the mass of a merger, the greater M_Dust increase for observations for two of the CIGALE runs, or the smaller the decrease for SIMBA. Observed mergers are typically more dusty than their non-merging counterparts but only because they typically have higher SFRs, regardless of whether they host AGN or not. SIMBA mergers follow observations when AGN hosts are included, but show reduced M_Dust when AGN hosts are removed. M_Dust in SIMBA is linked to AGN in a way not seen in observations.
ER -