<i>Gaia</i> DR2 unravels incompleteness of nearby cluster population: new open clusters in the direction of Perseus

Cantat-Gaudin, T.; Krone-Martins, A.; Sedaghat, Nima; Farahi, Arya; Souza, Rafael S. de; Skalidis, R.; Malz, Alex I.; Macêdo, Samuel; Moews, Ben; Jordi, C.; Moitinho, A.; Castro-Ginard, A.; Ishida, Emille E. O.; Heneka, Caroline; Boucaud, A.; Trindade, A. M. M.

doi:10.1051/0004-6361/201834453

Cited by 125 publications

(91 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The excluded entries are: BH 140 and FSR 1758 (that the paper showed to be globular clusters), FSR 1716 (another globular, Minniti et al 2017;Koch et al 2017) that is erroneously included in the study as it is not flagged as such in MWSC, and Harvard 5 (a Article number, page 3 of 24 A&A proofs: manuscript no. mirages duplicate of Collinder 258); e) 46 clusters (including 41 COIN-Gaia clusters) whose members were published in Cantat-Gaudin et al (2019b); f) 57 UBC clusters whose members were published in Castro-Ginard et al (2018) and Castro-Ginard et al (2019); g) three UFMG clusters whose members were published by Ferreira et al (2019); for a total of 1481 objects.…”

Section: Methodsmentioning

confidence: 99%

Clusters and mirages: cataloguing stellar aggregates in the Milky Way

Cantat-Gaudin

Anders

2020

A&A

Self Cite

245

View full text Add to dashboard Cite

Context.Many of the open clusters listed in modern catalogues were initially reported by visual astronomers as apparent overdensities of bright stars. As observational techniques and analysis methods continue to improve, some of them have been shown to be chance alignments of stars and not true clusters. Recent publications making use of Gaia DR2 data have provided membership lists for over a thousand clusters, however, many nearby objects listed in the literature have so far evaded detection. Aims. We aim to update the Gaia DR2 cluster census by performing membership determinations for known clusters that had been missed by previous studies and for recently-discovered clusters. We investigate a sub-set of non-detected clusters that, according to their literature parameters, should be easily visible in Gaia. Confirming or disproving the existence of old, inner-disc, high-altitude clusters is especially important as their survival or disruption is linked to the dynamical processes that drive the evolution of the Milky Way. Methods. We employed the Gaia DR2 catalogue and a membership assignment procedure, as well as visual inspections of spatial, proper motion, and parallax distributions. We used membership lists provided by other authors when available. Results. We derived membership lists for 150 objects, including ten that were already known prior to Gaia. We compiled a final list of members for 1481 clusters. Among the objects that we are still unable to identify with the Gaia data, we argue that many (mostly putatively old, relatively nearby, high-altitude objects) are not true clusters. Conclusions. At present, the only confirmed cluster located further than 500 pc away from the Galactic plane within the Solar circle is NGC 6791. It is likely that the objects discussed in this study only represent a fraction of the non-physical groupings erroneously listed in the catalogues as genuine open clusters and that those lists need further cleaning.

show abstract

Section: Methodsmentioning

confidence: 99%

Clusters and mirages: cataloguing stellar aggregates in the Milky Way

Cantat-Gaudin

Anders

2020

A&A

Self Cite

245

View full text Add to dashboard Cite

show abstract

“…All IDs start with 0 and correspond to the line number in the catalog (not the MWSC number as in K13). For CG18+19, IDs in the ranges 0 − 1228 and 1229 − 1274 correspond to star clusters in Cantat-Gaudin et al (2018) and Cantat-Gaudin et al (2019), respectively. For convenience, the names of the matched star clusters in CG18+19 are also presented.…”

Section: Star Cluster Classificationmentioning

confidence: 99%

“…Their newly discovered OCs increase the number of known OCs in the direction of Galactic anti-center by 22% as compared to known OC populations (Kharchenko et al 2013;Cantat-Gaudin et al 2018, 2019. Later on, Cantat-Gaudin et al (2019) applied a "coarse-to-fine" search method and again discovered 41 new star clusters in the direction of Perseus. Therefore, all these newly discovered star clusters point out a fact that many more efforts are required to obtain a complete census of Galactic OCs.…”

Section: Introductionmentioning

confidence: 99%

A Catalog of Newly Identified Star Clusters in Gaia DR2

Liu

Pang

2019

ApJS

189

249

View full text Add to dashboard Cite

We present the Star cluster Hunting Pipeline (SHiP) which can identify star clusters in Gaia DR2 data, and establish a star cluster catalog for the Galactic disk. A Friend of Friend based cluster finder method is used to identify star clusters using 5-dimensional stellar parameters, l, b, ̟, µ α cos δ, and µ δ . Our new catalog contains 2443 star cluster candidates identified from disk stars located within |b| = 25 • and with G < 18 mag. An automatic isochrone fitting scheme is applied to all cluster candidates. With a combination of parameters obtained from isochrone fitting, we classify cluster candidates into three classes (Class 1, 2 and 3). Class 1 clusters are the most probable star cluster candidates with the most stringent criteria. Most of these clusters are nearby (within 4 kpc). Our catalog is crossmatched with three Galactic star cluster catalogs, Kharchenko et al. (2013), Cantat-Gaudin et al. (2018, 2019), and Bica et al. (2019. The proper motion and parallax of matched star clusters are in good agreement with these earlier catalogs. We discover 76 new star cluster candidates that are not listed in these 3 catalogs. The majority of these are clusters older than log(age/yr) = 8.0, and are located in the inner disk with |b| < 5 • . The recent discovery of new star clusters suggests that current Galactic star cluster catalogs are still incomplete. Among the Class 1 cluster candidates, we find 56 candidates for star cluster groups. The pipeline, the catalog and the member list containing all candidates star clusters and star cluster groups have been made publicly available.

show abstract

“…in terms of Gaia observables, they share (l, b, , µ α * , µ δ ) and follow a specific pattern in a colour-magnitude diagram (CMD) (G, G BP , G RP ). That they can represent overdensities in five-dimensional astrometric space can be exploited by unsupervised learning algorithms to either characterise known OCs when looking for new member stars (Gao 2018a,b;Cantat-Gaudin et al 2018), or to detect new overdensities in the parameter space (Castro-Ginard et al 2018;Cantat-Gaudin et al 2019). Table 2 is only available at the CDS 1 https://www.cosmos.esa.int/web/gaia/dr2 Supervised learning methods can help in determining whether a group of stars is an OC by identifying the isochrone pattern of its member stars in a CMD, due to the common age of its members.…”

Section: Introductionmentioning

confidence: 99%

“…Additionally, the combination of ML techniques and Gaia DR2 data triggered the detection of new OCs. The discovery of nearby OCs (Castro-Ginard et al 2018;Cantat-Gaudin et al 2019), where the census was thought to be complete, showed the necessity to keep exploring the sky for new objects.…”

Section: Introductionmentioning

confidence: 99%

Hunting for open clusters in Gaia DR2: the Galactic anticentre

Castro-Ginard

Jordi

Luri

et al. 2019

A&A

Self Cite

124

View full text Add to dashboard Cite

Context. The Gaia Data Release 2 (DR2) provided an unprecedented volume of precise astrometric and excellent photometric data. In terms of data mining the Gaia catalogue, machine learning methods have shown to be a powerful tool, for instance in the search for unknown stellar structures. Particularly, supervised and unsupervised learning methods combined together significantly improves the detection rate of open clusters. Aims. We systematically scan Gaia DR2 in a region covering the Galactic anticentre and the Perseus arm (120 • ≤ l ≤ 205 • and −10 • ≤ b ≤ 10 • ), with the goal of finding any open clusters that may exist in this region, and fine tuning a previously proposed methodology successfully applied to TGAS data, adapting it to different density regions. Methods. Our methodology uses an unsupervised, density-based, clustering algorithm, DBSCAN, that identifies overdensities in the five-dimensional astrometric parameter space (l, b, , µ α * , µ δ ) that may correspond to physical clusters. The overdensities are separated into physical clusters (open clusters) or random statistical clusters using an artificial neural network to recognise the isochrone pattern that open clusters show in a colour magnitude diagram. Results. The method is able to recover more than 75% of the open clusters confirmed in the search area. Moreover, we detected 53 open clusters unknown previous to Gaia DR2, which represents an increase of more than 22% with respect to the already catalogued clusters in this region. Conclusions. We find that the census of nearby open clusters is not complete. Different machine learning methodologies for a blind search of open clusters are complementary to each other; no single method is able to detect 100% of the existing groups. Our methodology has shown to be a reliable tool for the automatic detection of open clusters, designed to be applied to the full Gaia DR2 catalogue.

show abstract

Gaia DR2 unravels incompleteness of nearby cluster population: new open clusters in the direction of Perseus

Cited by 125 publications

References 50 publications

Clusters and mirages: cataloguing stellar aggregates in the Milky Way

Clusters and mirages: cataloguing stellar aggregates in the Milky Way

A Catalog of Newly Identified Star Clusters in Gaia DR2

Hunting for open clusters in Gaia DR2: the Galactic anticentre

Contact Info

Product

Resources

About