Galaxy Zoo: Bars in Disk Galaxies

Arfon Smith (Oxford); Ben Hoyle (ICG; Chris Lintott (Oxford/Adler Planetarium); Daniel Thomas (ICG; Edward M. Edmondson (ICG; Karen L. Masters (ICG; Kevin Schawinski (Yale); Lucy Fortson (Adler Planetarium/Minnesota); Portsmouth); Portsmouth/Barcelona)

RECORD

Galaxy Zoo: Bars in Disk Galaxies

Karen L. Masters (ICG, Portsmouth), Robert C. Nichol (ICG, Ben Hoyle (ICG, Portsmouth/Barcelona), Chris Lintott (Oxford/Adler Planetarium), Steven Bamford (Nottingham), Edward M. Edmondson (ICG

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Lucy Fortson (Adler Planetarium/Minnesota), William C. Keel (Alabama), Kevin Schawinski (Yale), Arfon Smith (Oxford), Daniel Thomas (ICG

Cosmology and Nongalactic Astrophysics · Submitted 1 Mar 2010

abstract compiled · 2026-09-23 · no language-model review

The authors' main claim We see a clear increase in the bar fraction with redder (g-r) colours, decreased luminosity and in galaxies with more prominent bulges, to the extent that over half of the red, bulge-dominated, disk galaxies in our sample possess a bar.

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arXiv ID1003.0449 (version 2)

Pith IDSMULGSPW, Pith's permanent record of this paper and its review

CitationArfon Smith (Oxford), Ben Hoyle (ICG, Chris Lintott (Oxford/Adler Planetarium), Daniel Thomas (ICG, Edward M. Edmondson (ICG, Karen L. Masters (ICG, Kevin Schawinski (Yale), Lucy Fortson (Adler Planetarium/Minnesota), Portsmouth), Portsmouth/Barcelona), Robert C. Nichol (ICG, Steven Bamford (Nottingham), William C. Keel (Alabama). "Galaxy Zoo: Bars in Disk Galaxies." arXiv:1003.0449 (2010). https://pith.science/paper/SMULGSPW

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The compiled record

The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

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Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 5,902 input tokens, $0.0002 reported.

What the abstract itself states, as probabilities: claims first 0.11 · states limitation 0.53 · human participants 0.48 · controlled comparison 0.15 · randomized assignment 0.01 · states quantitative result 0.99 · compares with prior results 0.98 · mentions code or data availability 0.07.

The abstract, sentence by sentence

arXiv listing abstract v2. Results and the main claim are underlined; show every role.

We present first results from Galaxy Zoo 2, the second phase of the highly successful Galaxy Zoo project (www.galaxyzoo.org). Using a volume-limited sample of 13665 disk galaxies (0.01< z < 0.06 and M_r<-19.38), we study the fraction of galaxies with bars as a function of global galaxy properties like colour, luminosity and bulge prominence. Overall, 29.4+/-0.5% of galaxies in our sample have a bar, in excellent agreement with previous visually classified samples of galaxies (although this overall fraction is lower than measured by automated bar-finding methods). We see a clear increase in the bar fraction with redder (g-r) colours, decreased luminosity and in galaxies with more prominent bulges, to the extent that over half of the red, bulge-dominated, disk galaxies in our sample possess a bar. We see evidence for a colour bi-modality for our sample of disk galaxies, with a "red sequence" that is both bulge and bar-dominated, and a "blue cloud" which has little, or no, evidence for a (classical) bulge or bar. These results are consistent with similar trends for barred galaxies seen recently both locally and at higher redshift, and with early studies using the RC3. We discuss these results in the context of internal (secular) galaxy evolution scenarios and the possible links to the formation of bars and bulges in disk galaxies.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#	sentence	role	the authors' own work	states the main conclusion	strength
s0	We present first results from Galaxy Zoo 2, the second phase of the highly successful Galaxy Zoo project (www.galaxyzoo.org).	contribution 0.74	0.57	0.02	asserted 0.94
s1	Using a volume-limited sample of 13665 disk galaxies (0.01< z < 0.06 and M_r<-19.38), we study the fraction of galaxies with bars as a function of global galaxy properties like colour, luminosity and bulge prominence.	method 0.72	0.96	0.05	asserted 0.88
s2	Overall, 29.4+/-0.5% of galaxies in our sample have a bar, in excellent agreement with previous visually classified samples of galaxies (although this overall fraction is lower than measured by automated bar-finding methods).	result 1.00	0.94	0.28	asserted 1.00
s3	We see a clear increase in the bar fraction with redder (g-r) colours, decreased luminosity and in galaxies with more prominent bulges, to the extent that over half of the red, bulge-dominated, disk galaxies in our sample possess a bar.	result 1.00	0.97	0.38	asserted 1.00
s4	We see evidence for a colour bi-modality for our sample of disk galaxies, with a "red sequence" that is both bulge and bar-dominated, and a "blue cloud" which has little, or no, evidence for a (classical) bulge or bar.	result 0.98	0.94	0.19	asserted 0.98
s5	These results are consistent with similar trends for barred galaxies seen recently both locally and at higher redshift, and with early studies using the RC3.	interpretation 0.51	0.19	0.07	hedged possibility 0.98
s6	We discuss these results in the context of internal (secular) galaxy evolution scenarios and the possible links to the formation of bars and bulges in disk galaxies.	interpretation 1.00	0.36	0.06	unclear 0.77

What kind of paper the classifier reports this is: empirical study 0.98 · evidence from analysis of existing data 0.65.

What was examined, and what was not

sources read

arXiv listing abstract v2

not examined

full text
figures and tables
references and citing sentences
relations to other papers

levels run

P abstract

not run

S sections
T body sentences
C citations
R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

The paper

Original abstract

We present first results from Galaxy Zoo 2, the second phase of the highly successful Galaxy Zoo project (www.galaxyzoo.org). Using a volume-limited sample of 13665 disk galaxies (0.01< z < 0.06 and M_r<-19.38), we study the fraction of galaxies with bars as a function of global galaxy properties like colour, luminosity and bulge prominence. Overall, 29.4+/-0.5% of galaxies in our sample have a bar, in excellent agreement with previous visually classified samples of galaxies (although this overall fraction is lower than measured by automated bar-finding methods). We see a clear increase in the bar fraction with redder (g-r) colours, decreased luminosity and in galaxies with more prominent bulges, to the extent that over half of the red, bulge-dominated, disk galaxies in our sample possess a bar. We see evidence for a colour bi-modality for our sample of disk galaxies, with a "red sequence" that is both bulge and bar-dominated, and a "blue cloud" which has little, or no, evidence for a (classical) bulge or bar. These results are consistent with similar trends for barred galaxies seen recently both locally and at higher redshift, and with early studies using the RC3. We discuss these results in the context of internal (secular) galaxy evolution scenarios and the possible links to the formation of bars and bulges in disk galaxies.

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References

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

Bar likelihood in local galaxies: the joint role of stellar mass, morphology and environment
astro-ph.GA 2026-10 conditional novelty 5.0 of 10

Bar likelihood in local galaxies is set mainly by stellar mass and morphology; environmental trends are explained by the morphology-density relation.
ALMA2040: Understanding the Early Assembly of Galaxies - The Formation of Star-Forming Clumps and their Role in Shaping Galaxy Evolution
astro-ph.IM 2026-10 unverdicted novelty 2.0 of 10

A community white paper making the scientific case that the proposed ALMA2040 facility will revolutionize studies of high-redshift GMCs and star-forming clumps.

How later papers used it

100 later papers cite it

Evidence: substantial. 66 of the citing papers share no author with it, and 8 of those carry a confident label from Pith's citation classifier.

Pith read 16 of the 156 citing sentences, choosing only those whose citation markers point at this paper alone, and wrote the paraphrases from them. The summary, the counts, the evidence level, the links and the quotes come from code; the summary counts the papers listed below. A later paper is listed under a label when Pith's citation classifier gives one of its sentences that label at probability 0.8 or more (0.95 for support), Pith's reading finds that the citing paper itself did it, and a second check confirms the paraphrase against the sentence. This section lists uses only. It does not list criticism or disagreement, so their absence here says nothing about how the paper has been received. Papers that share an author with this one are listed apart, under "By the same authors". A quote is the citing authors' own sentence, shown when their paper's licence is CC BY, CC BY-SA or CC0. JSON

2 papers by the same authors are listed below: 2 used its method or tool.

Uses its method or tool 2 of 3 papers with this label · 2 by the same authors

By the same authors

Used this paper's prescription, selecting galaxies with p_bar > 0.5 as barred.

Galaxy Zoo: star-formation versus spiral arm number (2017) (same authors) · 1.00 · paraphrased: the licence does not allow quoting
Used this paper's definition of a strong bar, p_bar > 0.5, to classify bars in its own samples.

HI Rich but Low Star Formation galaxies in MaNGA: Physical Properties and Comparison to Control Samples (2023) (same authors) · 0.83 · paraphrased: the licence does not allow quoting

How the literature uses it

3 arXiv papers cite this in 3 sentences

Each citing sentence is taken from the citing paper's LaTeX source and typed by Pith's classifier. A label appears at probability 0.8 or more (0.95 for support), a contest at 0.7 or more; the quoted words are the citing authors'. How each label was checked · JSON

Papers citing it · 2 sentences without a confident label

Cites it as support 1 paper

Similarly, bars are more frequently found in bulge-dominated galaxies (e.g., Masters et al. [ref] ), which would also contribute to the trends we see.

Enhanced dust heating in the bulges of early-type spiral galaxies · Results · 0.99

What it cites · 4 sentences without a confident label

Compares with 1 paper

We note that [ref] finds this trend changes at masses$>10^11M_⊙$, but there are almost no such galaxies in our volume–limited sample.

Bars in early- and late-type disks in COSMOS · Comparison with Other Work · 0.87

Cites as background 1 paper

Many studies have attempted to separate the bar fraction into galaxies of different morphological types [ref] and a picture is emerging which suggests that the bar fraction found in a given sample might depend quite sensitively on the morphological and stellar mass make up of the sample being considered [ref] .

Multi-Wavelength Properties of Barred Galaxies in the Local Universe. I: Virgo Cluster · Comparison with Other Work · 0.95

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