We have used Galaxy Zoo DECaLS (GZD) to study strong and weak bars in disc galaxies. Out of the 314 000 galaxies in GZD, we created a volume-limited sample (0.01 < z < 0.05, Mr < − 18.96) which contains 1867 galaxies with reliable volunteer bar classifications in the ALFALFA footprint. In keeping with previous Galaxy Zoo surveys (such as GZ2), the morphological classifications from GZD agree well with previous morphological surveys. GZD considers galaxies to either have a strong bar (15.5 per cent), a weak bar (28.1 per cent) or no bar (56.4 per cent), based on volunteer classifications on images obtained from the DECaLS survey. This places GZD in a unique position to assess differences between strong and weak bars. We find that the strong bar fraction is typically higher in quiescent galaxies than in star-forming galaxies, while the weak bar fraction is similar. Moreover, we have found that strong bars facilitate the quenching process in star-forming galaxies, finding higher fibre star formation rates (SFRs), lower gas masses, and shorter depletion time-scales in these galaxies compared to unbarred galaxies. However, we also found that any differences between strong and weak bars disappear when controlling for bar length. Based on this, we conclude that weak and strong bars are not fundamentally different phenomena. Instead, we propose that there is a continuum of bar types, which varies from ‘weakest’ to ‘strongest’.
Géron, Tobias, Smethurst, R. J., Lintott, Chris, et al., "Galaxy zoo: stronger bars facilitate quenching in star-forming galaxies," Monthly Notices of the Royal Astronomical Society 507, no. 3 (2021), https://doi.org/10.1093/mnras/stab2064
@article{osti_1819986,
author = {Géron, Tobias and Smethurst, R. J. and Lintott, Chris and Kruk, Sandor and Masters, Karen L. and Simmons, Brooke and Stark, David V.},
title = {Galaxy zoo: stronger bars facilitate quenching in star-forming galaxies},
annote = {ABSTRACT We have used Galaxy Zoo DECaLS (GZD) to study strong and weak bars in disc galaxies. Out of the 314 000 galaxies in GZD, we created a volume-limited sample (0.01 < z < 0.05, Mr < − 18.96) which contains 1867 galaxies with reliable volunteer bar classifications in the ALFALFA footprint. In keeping with previous Galaxy Zoo surveys (such as GZ2), the morphological classifications from GZD agree well with previous morphological surveys. GZD considers galaxies to either have a strong bar (15.5 per cent), a weak bar (28.1 per cent) or no bar (56.4 per cent), based on volunteer classifications on images obtained from the DECaLS survey. This places GZD in a unique position to assess differences between strong and weak bars. We find that the strong bar fraction is typically higher in quiescent galaxies than in star-forming galaxies, while the weak bar fraction is similar. Moreover, we have found that strong bars facilitate the quenching process in star-forming galaxies, finding higher fibre star formation rates (SFRs), lower gas masses, and shorter depletion time-scales in these galaxies compared to unbarred galaxies. However, we also found that any differences between strong and weak bars disappear when controlling for bar length. Based on this, we conclude that weak and strong bars are not fundamentally different phenomena. Instead, we propose that there is a continuum of bar types, which varies from ‘weakest’ to ‘strongest’.},
doi = {10.1093/mnras/stab2064},
url = {https://www.osti.gov/biblio/1819986},
journal = {Monthly Notices of the Royal Astronomical Society},
issn = {ISSN 0035-8711},
number = {3},
volume = {507},
place = {United Kingdom},
publisher = {Oxford University Press},
year = {2021},
month = {07}}
US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Sloan Digital Sky Survey (SDSS)
Sponsoring Organization:
USDOE
Contributing Organization:
Sloan Digital Sky Survey (SDSS)
OSTI ID:
1819986
Alternate ID(s):
OSTI ID: 1982513
Journal Information:
Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 3 Vol. 507; ISSN 0035-8711