The DOI matches its Crossref record; 32 of the 32 references it cites were found in a registry or an index.
In Disguise or Out of Reach: First Clues about In Situ and Accreted Stars in the Stellar Halo of the Milky Way from Gaia DR2
Open accessAbstract
We investigate the nature of the double color–magnitude sequence observed in the Gaia DR2 HR diagram of stars with high transverse velocities. The stars in the reddest-color sequence are likely dominated by the dynamically hot tail of the thick disk population. Information from Nissen & Schuster and from the APOGEE survey suggests that stars in the blue-color sequence have elemental abundance patterns that can be explained by this population having a relatively low star formation efficiency during its formation. In dynamical and orbital spaces, such as the “Toomre diagram,” the two sequences show a significant overlap, but with a tendency for stars on the blue-color sequence to dominate regions with no or retrograde rotation and high total orbital energy. In the plane defined by the maximal vertical excursion of the orbits versus their apocenters, stars of both sequences redistribute into discrete wedges. We conclude that stars that are typically assigned to the halo in the solar vicinity are actually both accreted stars lying along the blue sequence in the HR diagram, and the low rotational velocity tail of the old Galactic disk, possibly dynamically heated by past accretion events. Our results imply that a halo population formed in situ and responsible for the early chemical enrichment prior to the formation of the thick disk has yet to be robustly identified, and that what has been defined as the stars of the in situ stellar halo of the Galaxy may in fact be fossil records of its last significant merger.
Overview
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Verification
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
The cited source says what the claim attributes to it.
In the citing paper
“The other very important contributor in the vicinity of the Sun to stars on halo-like orbits is the (tail of the) Milky Way thick disk (Gaia Collab. et al. 2018a, Haywood et al. 2018, Koppelman et al. 2018), as can be seen Figure 2a.”
From Streams, Substructures, and the Early History of the Milky Way (2020) · cites this paper as Haywood et al. 2018
The cited source says what the claim attributes to it.
In the citing paper
“However, the second sequence is populated by stars that, kinematically, are clearly part of the tail of the thick disk seen in Figure 5b (Di Matteo et al. 2019, Haywood et al. 2018).”
From Streams, Substructures, and the Early History of the Milky Way (2020) · cites this paper as Haywood et al. 2018
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
Citations
Cites
Prusti, T., de Bruijne, J. H. J., Brown, A. G. A., Vallenari, A., Babusiaux, C., Bailer‐Jones, C. A. L., Bastian, U., Biermann, M., Evans, D. W., Eyer, L., et al. (2016) · Astronomy and Astrophysics · doi:10.1051/0004-6361/201629272 · Cited by 7,350
Local kinematics and the local standard of rest
Schönrich, R. A., Binney, J. J., & Dehnen, W. (2010) · Monthly Notices of the Royal Astronomical Society · doi:10.1111/j.1365-2966.2010.16253.x · Cited by 1,934
The Apache Point Observatory Galactic Evolution Experiment (APOGEE)
Majewski, S. R., Schiavon, R. P., Frinchaboy, P. M., Prieto, C. A., Barkhouser, R., Bizyaev, D., Blank, B., Brunner, S., Burton, A., Carrera, R., et al. (2017) · The Astronomical Journal · doi:10.3847/1538-3881/aa784d · Cited by 1,831
galpy: A python LIBRARY FOR GALACTIC DYNAMICS
Bovy, J. (2015) · The Astrophysical Journal Supplement Series · doi:10.1088/0067-0049/216/2/29 · Cited by 1,655
Compositions of halo clusters and the formation of the galactic halo
Searle, L., & Zinn, R. (1978) · The Astrophysical Journal · doi:10.1086/156499 · Cited by 1,524
Reid, M. J., Menten, K. M., Brunthaler, A., Zheng, X. W., Dame, T. M., Xu, Y., Wu, Y., Zhang, B., Sanna, A., Sato, M., et al. (2014) · The Astrophysical Journal · doi:10.1088/0004-637x/783/2/130 · Cited by 1,379
A NEW GENERATION OF PARSEC-COLIBRI STELLAR ISOCHRONES INCLUDING THE TP-AGB PHASE
Marigo, P., Girardi, L., Bressan, A., Rosenfield, P. A., Aringer, B., Chen, Y., Dussin, M., Nanni, A., Pastorelli, G., Rodrigues, T. S., et al. (2017) · The Astrophysical Journal · doi:10.3847/1538-4357/835/1/77 · Cited by 1,031
Co-formation of the disc and the stellar halo★
Belokurov, V, Erkal, D., Evans, N. W., Koposov, S. E., & Deason, A. J. (2018) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/sty982 · Cited by 1,020
Chiba, M., & Beers, T. C. (2000) · The Astronomical Journal · doi:10.1086/301409 · Cited by 690
Two stellar components in the halo of the Milky Way
Carollo, D., Beers, T. C., Lee, Y. S., Chiba, M., Norris, J. E., Wilhelm, R., Sivarani, T., Marsteller, B., Munn, J. A., Bailer-Jones, C. A. L., et al. (2007) · Nature · doi:10.1038/nature06460 · Cited by 626
Research works printed but not linked: 1
- Allen, 1991, RMxAA, 22, 255
Cited by
Sorted by citations
Items 301–359 of 359
A Sequoia stellar candidate with very high 7Li and 9Be
Monaco, L., Caffau, E., Molaro, P. P., Bonifacio, P., & Cescutti, G. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202453574 · Cited by 2
Xie, R., Li, H., Zhang, R., Wu, Y., Xue, X.-X., Zhao, G., Zhang, S., & Xie, X. (2025) · The Astrophysical Journal · doi:10.3847/1538-4357/adcba6 · Cited by 2
Ding, L.-F., Li, J., Xue, X.-X., Tian, H., Yan, Z., & Zhao, G. (2025) · Research in Astronomy and Astrophysics · doi:10.1088/1674-4527/ade522 · Cited by 2
Monty, S., Strom, A. L., Stanton, T. M., Chruślińska, M., Cullen, F., Kobayashi, C., Starkenburg, T., Bhattacharya, S., Sanders, J. L., & Gieles, M. (2025) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/staf1213 · Cited by 2
Measuring and modelling the Splash with APOGEE/Gaia and ARTEMIS
Kisku, S. S., Schiavon, R. P., Font, A. S., Mason, A., Horta, D., Taylor, D. J., Sante, A., Fernández-Trincado, J. G., & Beers, T. C. (2025) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/staf1075 · Cited by 2
Milky Way’s Metal-poor Stars Display Chemical Transition near the Solar Radius
Malhan, K. (2025) · The Astrophysical Journal Letters · doi:10.3847/2041-8213/adf8d5 · Cited by 2
Identifying substructure associations in the Milky Way halo using chemo-kinematic tagging
Youakim, K., & LIND, K. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202554934 · Cited by 2
Kundu, A., Sanderson, R. E., Lidz, A., Gandhi, P. J., Wetzel, A. R., Feldmann, R., Panithanpaisal, N., Singh, J., & Boylan-Kolchin, M. (2026) · The Astrophysical Journal · doi:10.3847/1538-4357/ae32eb · Cited by 2
Chronology of our Galaxy from Gaia colour-magnitude diagram fitting (ChronoGal)
Ruiz-Lara, T., Mirabal, D., Gallart, C., Grand, R. J. J., Fragkoudi, F., Pérez, I., Cassisi, S., Fernández-Alvar, E., Queiroz, A. B. A., Aznar-Menargues, G., et al. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202556468 · Cited by 2
Buder, S., Buck, T., Skúladóttir, Á., Ness, M., McKenzie, M., & Monty, S. (2026) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stag1090 · Cited by 2
de Souza, G. F., Westera, P., Almeida-Fernandes, F., Limberg, G., Dias, B., Hernández-Jiménez, J. A., Herpich, F. R., Kerber, L. O., Machado-Pereira, E., Perottoni, H. D., et al. (2023) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stad3276 · Cited by 2
Visit Nearby Halo Substructures Using LAMOST DR9 MRS Data
唐, X.-Z. 馨. T., 赵, J.-K. 景. Z., 杨, Y. 勇. Y., Ye, X., Zhao, G., & 高, Q. 启. G. (2024) · The Astrophysical Journal · doi:10.3847/1538-4357/ad3240 · Cited by 2
Stellar substructures in the Galactic disc and halo: Properties, origins, and evolution
Deepak (2024) · Journal of Astrophysics and Astronomy · doi:10.1007/s12036-024-10011-1 · Cited by 2
Lane, J., & Bovy, J. (2025) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/staf294 · Cited by 2
3D non-LTE Ca II line formation in metal-poor FGK stars
Lagae, C., Amarsi, A. M., & LIND, K. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202452874 · Cited by 3
Li, Z., Li, C., Zhao, G., Zhang, R., & Xue, X.-X. (2025) · The Astrophysical Journal · doi:10.3847/1538-4357/ade430 · Cited by 2
A Hint of Three-section Halo As Seen from the APOGEE DR14
Chen, Y., Zhao, G., Xue, X.-X., Zhao, J., Liang, X., Jia, Y., & Yang, C. (2019) · The Astrophysical Journal · doi:10.3847/1538-4357/aaf80f · Cited by 2
Partitioning the Galactic halo with Gaussian Mixture Models
Liang, X., Chen, Y., Zhao, J., & Zhao, G. (2021) · Research in Astronomy and Astrophysics · doi:10.1088/1674-4527/21/5/128 · Cited by 2
Investigation of Substructures of the Inner Halo Using the StarGO Algorithm with APOGEE DR17
Li, Z., Du, C., Liu, H., & Ye, D. (2025) · The Astrophysical Journal · doi:10.3847/1538-4357/adc809 · Cited by 1
He, W.-B., Zhou, P., Gjergo, E., & Fu, X. (2025) · The Astrophysical Journal · doi:10.3847/1538-4357/add32b · Cited by 1
Searching for stars ejected from the Galactic Centre in DESI
Verberne, S., Koposov, S. E., Rossi, E. M., & Penoyre, Z. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202555939 · Cited by 1
Purandardas, M., Aroli-Veettil, S., Ray, S., Mathew, B., Kartha, S. S., Sreeshma, N. M., & Haridas, S. (2025) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/staf2215 · Cited by 1
Xie, R., Yuan, Z., Li, H., Matsuno, T., Martin, N. F., Zhang, R., Yan, Z., Sestito, F., Thomas, G. F., Banerjee, P., et al. (2026) · The Astrophysical Journal · doi:10.3847/1538-4357/ae39c8 · Cited by 1
Placco, V. M., Limberg, G., Kennedy, C. R., & Christlieb, N. (2026) · The Astrophysical Journal Letters · doi:10.3847/2041-8213/ae4dea · Cited by 1
Tomlinson, T., Fragkoudi, F., Carrillo, A., Fattahi, A., Gherghinescu, P., Deason, A. J., Pakmor, R., Grand, R. J. J., Gómez, F. A., van de Voort, F., et al. (2026) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stag841 · Cited by 1
An Ancient Brown Dwarf Transiting a Metal-poor Thick-disk Star
Redai, J. A., Chandra, V., Yee, S. W., DiTomasso, V., Andrews, S., Öberg, K. I., Charbonneau, D., Woody, T., Latham, D. W., Bieryla, A., et al. (2026) · The Astrophysical Journal Letters · doi:10.3847/2041-8213/ae4ec5 · Cited by 3
The Velocity Field of Our Milky Way Outer Stellar Halo Based on DESI DR2
Li, S., Wang, W., Koposov, S. E., Amarante, J. A. S., Deason, A. J., Valluri, M., Li, T. S., Byström, A., Lambert, M., Qiu, T., et al. (2026) · The Astrophysical Journal · doi:10.3847/1538-4357/ae7346 · Cited by 1
Disentangling Milky Way halo populations at low metallicities using [Al/Fe]
Ernandes, H., Skúladóttir, Á., Feltzing, S., & Feuillet, D. K. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202557149 · Cited by 1
Evidence of ancient Milky Way merger
Venn, K. A. (2018) · Nature · doi:10.1038/d41586-018-07193-4 · Cited by 1
Gallart, C., Ruiz-Lara, T., Bernard, E. J., Brook, C. B. A., Cassisi, S., Hill, V., & Monelli, M. (2019) · Figshare · doi:10.5281/zenodo.3089010 · Cited by 1
Gaia results for star clusters and dwarf galaxies in the Milky Way
Massari, D. (2019) · Proceedings of the International Astronomical Union · doi:10.1017/s1743921319006793
Elemental Abundances in the Local Group: Tracing the Formation History of the Great Andromeda GalaxyPreprint
Escala, I. (2020) · arXiv (Cornell University) · doi:10.7907/16bk-vm98
Matteo, P. D. (2021) · Galaxies · doi:10.1002/9781119818007.ch2
Gallart, C., Bernard, E. J., Brook, C. B., Ruiz-Lara, T., Cassisi, S., Hill, V., & Monelli, M. (2019) · Figshare · doi:10.5281/zenodo.3228142
Barium and europium abundances in high- and low-α halo stars
Wang, G., Li, J., Chang, Z., Shi, J., Li, Z., Tian, M., & Cui, W. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202346883
Impact of merger histories on the timing argument estimate of the Local Group mass
Akib, I., Hammer, F., & Yang, Y. (2025) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202553769
Emami, R., Hernquist, L., Smith, R. K., Steiner, J. F., Tremblay, G. R., Finkbeiner, D. P., Vogelsberger, M., Grindlay, J., Marinacci, F., Su, K.-Y., et al. (2025) · Publications of the Astronomical Society of Australia · doi:10.1017/pasa.2025.10032
Dynamical properties of high-[Mg/Fe] stars in the Milky Way bar region
Pandey, A., & Gerhard, O. (2025) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/staf1328
Suda, T., François, P., Wanajo, S., Caffau, E., Aoki, W., & Bonifacio, P. (2025) · Publications of the Astronomical Society of Japan · doi:10.1093/pasj/psaf078
The GALAH survey: Searching for and characterizing halo substructures with the GALAH DR4 survey
Kushniruk, I., Youakim, K., Lind, K., Buder, S., Kos, J., Feuillet, D. K., Martell, S. L., de Grijs, R., Lewis, G. F., Bland‐Hawthorn, J., et al. (2026) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202451201
Probing the Milky Way halo with RR Lyrae stars from Gaia Data Release 3
Muraveva, T., Monti, L., Massari, D., Leo, M. D., Garofalo, A., Clementini, G., Ceccarelli, E., & Michelucci, U. (2026) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202658986
Bar Formation during a Gaia-Sausage-Enceladus-like Merger Event
Chen, B.-H., Shen, J., & Matteo, P. D. (2026) · The Astrophysical Journal · doi:10.3847/1538-4357/ae47e6
Characterizing the Velocity Anisotropy of the Milky Way’s Stellar Halo
Barbosa, F. O., Pérez-Villegas, Á., Rossi, S., Santucci, R. M., Aguilar, L., Perottoni, H. D., Limberg, G., Borbolato, L., & Nogueira-Santos, J. V. (2026) · The Astrophysical Journal · doi:10.3847/1538-4357/ae8fd6
Tracing Early Enrichment Pathways: Chemical and Chemodynamical Analysis of Two CEMP-no Stars*
Purandardas, M. (2026) · The Astronomical Journal · doi:10.3847/1538-3881/ae5f93
Investigation of high-quality spectra of a sample of high-radial-velocity stars
Alazzawi, J., Caffau, E., Bonifacio, P., Çal, S., Monaco, L., Sbordone, L., & Lombardo, L. (2026) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202659789
Akbaba, F., & Plevne, O. (2026) · Publications of the Astronomical Society of the Pacific · doi:10.1088/1538-3873/ae8477
The Epoch of the GSE Merger: Insights from the Splash and Thick-disk Age Distributions
鲁, S. 思. L., Huang, Y., Feng, Q., & Zhang, H. (2026) · The Astrophysical Journal Letters · doi:10.3847/2041-8213/ae853d
Beryllium enhancement in stars of the accreted Thamnos-2 system
Molaro, P. P., Bonifacio, P., Caffau, E., Monaco, L., & Cescutti, G. (2026) · Astronomy and Astrophysics · doi:10.1051/0004-6361/202660745
Tracing the accretion history of the Milky Way with halo stars
Mori, A., Matteo, P. D., & Salvadori, S. (2024) · Proceedings of the International Astronomical Union · doi:10.1017/s1743921325001000
The accretion history of the Galaxy via field and globular cluster populations
Horta, D. (2024) · Proceedings of the International Astronomical Union · doi:10.1017/s1743921326106334
The Low- α Splash Population in the Milky Way
Borbolato, L., Amarante, J. A. S., Perottoni, H. D., Rossi, S., Debattista, V. P., Li, Z., Deg, N., & Khachaturyants, T. (2026) · The Astrophysical Journal Letters · doi:10.3847/2041-8213/ae9605
ACACIAS II: element abundances for 39 stars in the dwarf galaxy Sculptor
Cárdenas, A. C., Buder, S., Ness, M., & Mendel, J. T. (2026) · Monthly Notices of the Royal Astronomical Society · doi:10.1093/mnras/stag1753
Investigation of Galactic Populations and Merger Process Using Machine Learning Methods
Akbaba, F. (2025) · Proceedings of the International Astronomical Union · doi:10.1017/s1743921326106255
Sun, T., Xiang, M., Bi, S., Liu, J., Zhang, M., & Wu, Y. (2026) · The Astronomical Journal · doi:10.3847/1538-3881/aeac24
Metadata
- Authors
- Haywood, M., Di Matteo, P., Lehnert, M. D., Snaith, O., Khoperskov, S., & Gómez, A.
- Affiliations
- Centre National de la Recherche Scientifique (FR)
- Korea Institute for Advanced Study (KR)
- Corresponding author
- Haywood, M.
- Gómez, A.
- Venue
- The Astrophysical Journal
- Publisher
- American Astronomical Society
- Published
- 2018-08-16
- Volume
- 863
- Issue
- 2
- Pages
- 113
- ISSN
- 0004-637X (ISSN-L)
- 1538-4357
- OpenAlex
- W2802061397
- Cited by
- 360
- References
- 32
- Citations by year
- 2026: 26 · 2025: 54 · 2024: 49 · 2023: 46 · 2022: 42 · 2021: 55 · 2020: 46 · 2019: 33 · 2018: 9
- FWCI
- 19.29
- Type
- journal article
- Language
- en
- Open access
- green
- arxiv.org
- Licence
- Locations
- The Astrophysical Journal (publishedVersion)
- arXiv (Cornell University) (submittedVersion)
- HAL (submittedVersion, cc-by)
- HAL (submittedVersion)
- arXiv (Cornell University)
- Funders
- Agence Nationale de la Recherche (ANR-15-CE31-0007)
- Topics
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Stellar, planetary, and galactic studies
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Galaxies: Formation, Evolution, Phenomena
- Physical Sciences › Physics and Astronomy › Astronomy and Astrophysics › Astrophysics and Star Formation Studies
- Keywords
- Milky Way stellar halo, thick disk, retrograde rotation, orbital energies, chemical enrichment, Gaia DR2, APOGEE
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
