VEGAS: A VST Early-type GAlaxy Survey.VI. The diffuse light in HCG 86 from the ultra-deep VEGAS images

2); (2) University of Naples Federico II; (3) School of Physics University of New South Wales; (4) INAF Astronomical Abruzzo Observatory; (5) Centre for Astrophysics; (6) Instituto de Astrofisica Facultad de Fisica Pontificia Universidad Catolica de Chile; (7) INAF Astronomical Observatory of Padova); Antonio La Marca (2); Duncan A. Forbes (5); Enrichetta Iodice (1)

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VEGAS: A VST Early-type GAlaxy Survey.VI. The diffuse light in HCG 86 from the ultra-deep VEGAS images

Rossella Ragusa (1, 2), Marilena Spavone (1), Enrichetta Iodice (1), Sarah Brough (3), Maria Angela Raj (1), Maurizio Paolillo (2), Michele Cantiello (4)

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Duncan A. Forbes (5), Antonio La Marca (2), Giuseppe D Ago (6), Roberto Rampazzo (7), Pietro Schipani (1) ((1) INAF Astronomical Observatory of Capodimonte, (2) University of Naples Federico II, (3) School of Physics University of New South Wales, (4) INAF Astronomical Abruzzo Observatory, (5) Centre for Astrophysics, Supercomputing Swinburne University of Technology, (6) Instituto de Astrofisica Facultad de Fisica Pontificia Universidad Catolica de Chile, (7) INAF Astronomical Observatory of Padova)

Astrophysics of Galaxies · Submitted 14 May 2021

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

The authors' main claim By comparing the IGL fraction and colors with those predicted by simulations, the amount of IGL in HCG 86 would be the result of the disruption of satellites at an epoch of z ~ 0.4.

how it is stated · hedged possibility 0.90 read the record →

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arXiv ID2105.06970 (version 1)

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

Citation2), (2) University of Naples Federico II, (3) School of Physics University of New South Wales, (4) INAF Astronomical Abruzzo Observatory, (5) Centre for Astrophysics, (6) Instituto de Astrofisica Facultad de Fisica Pontificia Universidad Catolica de Chile, (7) INAF Astronomical Observatory of Padova), Antonio La Marca (2), Duncan A. Forbes (5), Enrichetta Iodice (1), Giuseppe D Ago (6), Maria Angela Raj (1), Marilena Spavone (1), Maurizio Paolillo (2), Michele Cantiello (4), Pietro Schipani (1) ((1) INAF Astronomical Observatory of Capodimonte, Roberto Rampazzo (7), Rossella Ragusa (1, Sarah Brough (3), Supercomputing Swinburne University of Technology. "VEGAS: A VST Early-type GAlaxy Survey.VI. The diffuse light in HCG 86 from the ultra-deep VEGAS images." arXiv:2105.06970 (2021). https://pith.science/paper/JMNQXIZO

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Compiled by classifier-1.13.0 via TypeSafe API, question bank abstract-p1-20260923, 2026-09-23: 1 request, 9,079 input tokens.

What the abstract itself states, as probabilities: claims first 0.06 · states limitation 0.11 · human participants 0.01 · controlled comparison 0.10 · randomized assignment 0.01 · states quantitative result 0.99 · compares with prior results 0.95 · mentions code or data availability 0.03.

The abstract, sentence by sentence

arXiv listing abstract v1. Results and the main claim are underlined; show every role.

Context. In this paper we present ultra deep images of the compact group of galaxies HCG 86 as part of the VEGAS survey. Aims. Our main goals are to estimate the amount of intragroup light (IGL), to study the light and color distributions in order to address the main formation process of the IGL component in groups of galaxies. Methods. We derived the azimuthally averaged surface brightness profiles in the g,r and i bands with g - r and r - i average colors and color profiles for all group members. By fitting the light distribution, we have extrapolated the contribution of the stellar halos plus the diffuse light from the brightest component of each galaxy. The results are compared with theoretical predictions. Results. The long integration time and wide area covered make our data deeper than previous literature studies of the IGL in compact groups of galaxies and allow us to produce an extended (~160 kpc) map of the IGL, down to a surface brightness level of about 30 mag/arcsec^2 in the g band. The IGL in HCG 86 is mainly in diffuse form and has average colors of g - r ~ 0.8 mag and r - i ~ 0.4 mag. The fraction of IGL in HCG 86 is ~ 16% of the total luminosity of the group, and this is consistent with estimates available for other compact groups and loose groups of galaxies of similar virial masses. A weak trend is present between the amount of IGL and the early-type to late-type galaxy ratio. Conclusions. By comparing the IGL fraction and colors with those predicted by simulations, the amount of IGL in HCG 86 would be the result of the disruption of satellites at an epoch of z ~ 0.4. At this redshift, observed colors are consistent with the scenario where the main contribution to the mass of the IGL comes from the intermediate-massive 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	Context.	background 1.00	0.03	0.01	unclear 1.00
s1	In this paper we present ultra deep images of the compact group of galaxies HCG 86 as part of the VEGAS survey. Aims.	contribution 0.99	0.85	0.01	asserted 0.83
s2	Our main goals are to estimate the amount of intragroup light (IGL), to study the light and color distributions in order to address the main formation process of the IGL component in groups of galaxies. Methods.	contribution 0.89	0.34	0.02	asserted 0.69
s3	We derived the azimuthally averaged surface brightness profiles in the g,r and i bands with g - r and r - i average colors and color profiles for all group members.	method 1.00	0.97	0.02	asserted 1.00
s4	By fitting the light distribution, we have extrapolated the contribution of the stellar halos plus the diffuse light from the brightest component of each galaxy.	method 1.00	0.96	0.03	asserted 1.00
s5	The results are compared with theoretical predictions. Results.	method 0.45	0.12	0.02	unclear 0.90
s6	The long integration time and wide area covered make our data deeper than previous literature studies of the IGL in compact groups of galaxies and allow us to produce an extended (~160 kpc) map of the IGL, down to a surface brightness level of about 30 mag/arcsec^2 in the g band.	result 0.90	0.96	0.07	asserted 1.00
s7	The IGL in HCG 86 is mainly in diffuse form and has average colors of g - r ~ 0.8 mag and r - i ~ 0.4 mag.	result 1.00	0.96	0.11	asserted 1.00
s8	The fraction of IGL in HCG 86 is ~ 16% of the total luminosity of the group, and this is consistent with estimates available for other compact groups and loose groups of galaxies of similar virial masses.	result 0.99	0.92	0.10	asserted 0.64
s9	A weak trend is present between the amount of IGL and the early-type to late-type galaxy ratio. Conclusions.	result 1.00	0.90	0.05	asserted 0.85
s10	By comparing the IGL fraction and colors with those predicted by simulations, the amount of IGL in HCG 86 would be the result of the disruption of satellites at an epoch of z ~ 0.4.	interpretation 0.99	0.70	0.68	hedged possibility 0.90
s11	At this redshift, observed colors are consistent with the scenario where the main contribution to the mass of the IGL comes from the intermediate-massive galaxies.	interpretation 0.99	0.56	0.16	hedged possibility 0.80

What kind of paper the classifier reports this is: empirical study 1.00 · evidence from observation or experiment 0.99.

What was examined, and what was not

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arXiv listing abstract v1

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full text
figures and tables
references and citing sentences
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T body sentences
C citations
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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

Context. In this paper we present ultra deep images of the compact group of galaxies HCG 86 as part of the VEGAS survey. Aims. Our main goals are to estimate the amount of intragroup light (IGL), to study the light and color distributions in order to address the main formation process of the IGL component in groups of galaxies. Methods. We derived the azimuthally averaged surface brightness profiles in the g,r and i bands with g - r and r - i average colors and color profiles for all group members. By fitting the light distribution, we have extrapolated the contribution of the stellar halos plus the diffuse light from the brightest component of each galaxy. The results are compared with theoretical predictions. Results. The long integration time and wide area covered make our data deeper than previous literature studies of the IGL in compact groups of galaxies and allow us to produce an extended (~160 kpc) map of the IGL, down to a surface brightness level of about 30 mag/arcsec^2 in the g band. The IGL in HCG 86 is mainly in diffuse form and has average colors of g - r ~ 0.8 mag and r - i ~ 0.4 mag. The fraction of IGL in HCG 86 is ~ 16% of the total luminosity of the group, and this is consistent with estimates available for other compact groups and loose groups of galaxies of similar virial masses. A weak trend is present between the amount of IGL and the early-type to late-type galaxy ratio. Conclusions. By comparing the IGL fraction and colors with those predicted by simulations, the amount of IGL in HCG 86 would be the result of the disruption of satellites at an epoch of z ~ 0.4. At this redshift, observed colors are consistent with the scenario where the main contribution to the mass of the IGL comes from the intermediate-massive galaxies.

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2 arXiv papers cite this in 7 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

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The most recent observations (e.g., [ref] ) have found a clear radial gradient that, as just argued, favors stellar stripping to mergers as the main mechanism for the formation of the ICL.

On The Origin And Evolution Of The Intra-Cluster Light: A Brief Review Of The Most Recent Developments · ICL Colors, Metallicity and Age · 0.98

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Compares with 2 papers

The BGG/(BGG+IGL) fraction in HCG 86 is equal to 60$%$, in agreement with the simulations performed by [ref] for a halo with $M_vir∼10^13$ M$_⊙$.

Brightest Cluster Galaxies and Intra-Cluster Light: Their Mass Distribution in the Innermost Regions of Groups and Clusters · The intra-group light in HCG 86 · 0.95
Moreover, such a value is consistent with the $g-r$ colors derived in other groups and galaxy clusters, where $g-r=0.68$ mag in the Abell Cluster 2744 at z=0.3 [ref] , $g-r∼0.7$ mag in the Fornax Cluster [ref] and also consistent with $g-i∼1.3$ mag found in the Abell Cluster 85 [ref] .

The buildup of the intracluster light of Abell 85 as seen by Subaru's Hyper Suprime-Cam · The intra-group light in HCG 86 · 0.95

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