The Gaia-ESO Survey: Preparing the ground for 4MOST and WEAVE galactic surveys (2023)
Journal Article
Nepal, S., Guiglion, G., de Jong, R., Valentini, M., Chiappini, C., Steinmetz, M., Ambrosch, M., Pancino, E., Jeffries, R., Bensby, T., Romano, D., Smiljanic, R., Dantas, M., Gilmore, G., Randich, S., Bayo, A., Bergemann, M., Franciosini, E., Jiménez-Esteban, F., Jofré, P., …Zaggia, S. (2023). The Gaia-ESO Survey: Preparing the ground for 4MOST and WEAVE galactic surveys. Astronomy & Astrophysics, 671, Article A61. https://doi.org/10.1051/0004-6361/202244765

Context. Originating from several sources (Big Bang, stars, cosmic rays) and being strongly depleted during stellar lifetime, the lithium element is of great interest as its chemical evolution in the Milky Way is not yet well understood. To help cons... Read More about The Gaia-ESO Survey: Preparing the ground for 4MOST and WEAVE galactic surveys.

Low mass young stars in the Milky Way unveiled by DBSCAN and Gaia EDR3. Mapping the star forming regions within 1.5 Kpc (2022)
Journal Article
Prisinzano, L., Damiani, F., Sciortino, S., Flaccomio, E., Guarcello, M., Micela, G., Tognelli, E., Jeffries, R., & Alcalá, J. (2022). Low mass young stars in the Milky Way unveiled by DBSCAN and Gaia EDR3. Mapping the star forming regions within 1.5 Kpc. Astronomy and Astrophysics, https://doi.org/10.1051/0004-6361/202243580

With an unprecedented astrometric and photometric data precision, Gaia EDR3 gives us, for the first time, the opportunity to systematically detect and map in the optical bands, the low mass populations of the star forming regions (SFRs) in the Milky... Read More about Low mass young stars in the Milky Way unveiled by DBSCAN and Gaia EDR3. Mapping the star forming regions within 1.5 Kpc.

The Gaia-ESO survey: A lithium depletion boundary age for NGC 2232 (2021)
Journal Article
Binks, A. S., Jeffries, R. D., Jackson, R. J., Franciosini, E., Sacco, G. G., Bayo, A., Magrini, L., Randich, S., Arancibia-Silva, J., Bergemann, M., Bragaglia, A., Gilmore, G., Gonneau, A., Hourihane, A., Jofré, P., Korn, A. J., Morbidelli, L., Prisinzano, L., Worley, C. C., & Zaggia, S. (2021). The Gaia-ESO survey: A lithium depletion boundary age for NGC 2232. Monthly Notices of the Royal Astronomical Society, 505(1), 1280-1292

Astrometry and photometry from {\it Gaia} and spectroscopic data from the {\it Gaia}-ESO Survey (GES) are used to identify the lithium depletion boundary (LDB) in the young cluster NGC 2232. A specialised spectral line analysis procedure was used to... Read More about The Gaia-ESO survey: A lithium depletion boundary age for NGC 2232.

The Gaia-ESO Survey: Galactic evolution of lithium at high metallicity (2020)
Journal Article
Jeffries, R., & Wright, N. J. (2020). The Gaia-ESO Survey: Galactic evolution of lithium at high metallicity. Astronomy and Astrophysics, https://doi.org/10.1051/0004-6361/202038688

Context. Reconstructing the Galactic evolution of lithium (Li) is the main tool used to constrain the source(s) of Li enrichment in the Galaxy. Recent results have suggested a decline in Li at supersolar metallicities, which may indicate reduced prod... Read More about The Gaia-ESO Survey: Galactic evolution of lithium at high metallicity.

The Gaia-ESO survey: the non-universality of the age-chemical-clocks-metallicity relations in the Galactic disc (2020)
Journal Article
Jeffries. (2020). The Gaia-ESO survey: the non-universality of the age-chemical-clocks-metallicity relations in the Galactic disc. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202038055

Context. In the era of large spectroscopic surveys, massive databases of high-quality spectra coupled with the products of the Gaia satellite provide tools to outline a new picture of our Galaxy. In this framework, an important piece of information i... Read More about The Gaia-ESO survey: the non-universality of the age-chemical-clocks-metallicity relations in the Galactic disc.

The Gaia-ESO Survey: Membership probabilities for stars in 32 open clusters from 3D kinematics (2020)
Journal Article
Jeffries, & Wright. (2020). The Gaia-ESO Survey: Membership probabilities for stars in 32 open clusters from 3D kinematics. Monthly Notices of the Royal Astronomical Society, 4701-4716. https://doi.org/10.1093/mnras/staa1749

The Gaia-ESO Survey (GES) observed many open clusters as part of its programme to spectroscopically characterise the various Milky Way populations. GES spectroscopy and Gaia astrometry from its second data release are used here to assign membership p... Read More about The Gaia-ESO Survey: Membership probabilities for stars in 32 open clusters from 3D kinematics.

The Gaia-ESO Survey: detection and characterisation of single-line spectroscopic binaries (2020)
Journal Article
Merle, T., Van der Swaelmen, M., Van Eck, S., Jorissen, A., Jackson, R. J., Traven, G., Zwitter, T., Pourbaix, D., Klutsch, A., Sacco, G., Blomme, R., Masseron, T., Gilmore, G., Randich, S., Badenes, C., Bayo, A., Bensby, T., Bergemann, M., Biazzo, K., Damiani, F., …Prisinzano, L. (2020). The Gaia-ESO Survey: detection and characterisation of single-line spectroscopic binaries. Astronomy & Astrophysics, 635, https://doi.org/10.1051/0004-6361/201935819

Context. Multiple stellar systems play a fundamental role in the formation and evolution of stellar populations in galaxies. Recent and ongoing large ground-based multi-object spectroscopic surveys significantly increase the sample of spectroscopic b... Read More about The Gaia-ESO Survey: detection and characterisation of single-line spectroscopic binaries.

The Gaia_ESO Survey: double, triple and quadruple-line spectroscopic binary candidates (2017)
Journal Article
Jeffries. (2017). The Gaia_ESO Survey: double, triple and quadruple-line spectroscopic binary candidates. Astronomy and Astrophysics, https://doi.org/10.1051/0004-6361/201730442

Context. The Gaia-ESO Survey (GES) is a large spectroscopic survey that provides a unique opportunity to study the distribution of spectroscopic multiple systems among different populations of the Galaxy. Aims. Our aim is to detect binarity/multiplic... Read More about The Gaia_ESO Survey: double, triple and quadruple-line spectroscopic binary candidates.

The Gaia-ESO Survey: Dynamical analysis of the L1688 region in Ophiuchus (2016)
Journal Article
Jeffries, R., & Wright, N. J. (2016). The Gaia-ESO Survey: Dynamical analysis of the L1688 region in Ophiuchus. Astronomy and Astrophysics Supplement Series, https://doi.org/10.1051/0004-6361/201527253

The Gaia ESO Public Spectroscopic Survey (GES) is providing the astronomical community with high-precision measurements of many stellar parameters including radial velocities (RVs) of stars belonging to several young clusters and star-forming regions... Read More about The Gaia-ESO Survey: Dynamical analysis of the L1688 region in Ophiuchus.

Spectroscopic confirmation of M-dwarf candidate members of the Beta Pictoris and AB Doradus Moving Groups (2015)
Journal Article
Binks, A., & Jeffries, R. (2016). Spectroscopic confirmation of M-dwarf candidate members of the Beta Pictoris and AB Doradus Moving Groups. Monthly Notices of the Royal Astronomical Society, 455(3), 3345-3358. https://doi.org/10.1093/mnras/stv2431

Optical spectroscopic observations are reported for 24 and 23, nearby, proper-motion-selected M-dwarf candidate members of the Beta Pictoris and AB Doradus moving groups (BPMG and ABDMG). Using kinematic criteria, the presence of both Halpha emission... Read More about Spectroscopic confirmation of M-dwarf candidate members of the Beta Pictoris and AB Doradus Moving Groups.

The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo (2015)
Journal Article
Jeffries. (2015). The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo. Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/201425554

A small fraction of the halo field is made up of stars that share the light element (Z = 13) anomalies characteristic of second generation globular cluster (GC) stars. The ejected stars shed light on the formation of the Galactic halo by tracing the... Read More about The Gaia-ESO Survey: A globular cluster escapee in the Galactic halo.

The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars (2014)
Journal Article
Smiljanic, R., Korn, A., Bergemann, M., Frasca, A., Magrini, L., Masseron, T., Pancino, E., Ruchti, G., San Roman, I., Sbordone, L., Sousa, S., Tabernero, H., Tautvaišienė, G., Valentini, M., Weber, M., Worley, C., Zh. Adibekyan, V., Allende Prieto, C., Barisevičius, G., Biazzo, K., …Zaggia, S. (2014). The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars. Astronomy and Astrophysics, 570, Article A122. https://doi.org/10.1051/0004-6361/201423937

Context. The ongoing Gaia-ESO Public Spectroscopic Survey is using FLAMES at the VLT to obtain high-quality medium-resolution Giraffe spectra for about 105 stars and high-resolution UVES spectra for about 5000 stars. With UVES, the Survey has already... Read More about The Gaia-ESO Survey: The analysis of high-resolution UVES spectra of FGK-type stars.

On the relationship between the size and surface coverage of starspots on magnetically active low-mass stars (2013)
Journal Article
Jackson, R. J., & Jeffries, R. D. (2013). On the relationship between the size and surface coverage of starspots on magnetically active low-mass stars. Monthly Notices of the Royal Astronomical Society, 431(2), 1883-1890. https://doi.org/10.1093/mnras/stt304

We present a model that predicts the light curve amplitude distribution for an ensemble of low-mass magnetically active stars, under the assumptions that stellar spin axes are randomly orientated and that cool starspots have a characteristic scale le... Read More about On the relationship between the size and surface coverage of starspots on magnetically active low-mass stars.

The low-mass Initial Mass Function in the young cluster NGC 6611 (2009)
Journal Article
Jeffries, M. Oliveira, J., D. Jeffries, R., & Th. van Loon, J. (2009). The low-mass Initial Mass Function in the young cluster NGC 6611. Monthly Notices of the Royal Astronomical Society, 1034-1050. https://doi.org/10.1111/j.1365-2966.2008.14140.x

NGC 6611 is the massive young cluster (2-3 Myr) that ionises the Eagle Nebula. We present very deep photometric observations of the central region of NGC 6611 obtained with the Hubble Space Telescope and the following filters: ACS/WFC F775W and F850L... Read More about The low-mass Initial Mass Function in the young cluster NGC 6611.

Kinematic structure in the young σ Orionis association (2006)
Journal Article
Jeffries, R., Maxted, P., Oliveira, J., & Naylor, T. (2006). Kinematic structure in the young σ Orionis association. Monthly Notices of the Royal Astronomical Society, 371(1), L6 - L10. https://doi.org/10.1111/j.1745-3933.2006.00196.x

We have used precise radial velocity measurements for a large number of candidate low-mass stars and brown dwarfs, to show that the young Sigma Ori ``cluster'' consists of two spatially superimposed components which are kinematically separated by 7 k... Read More about Kinematic structure in the young σ Orionis association.

Circumstellar discs in the young σ Orionis cluster (2006)
Journal Article
Oliveira, J., Jeffries, R., Van Loon, J., & Rushton, M. (2006). Circumstellar discs in the young σ Orionis cluster. Monthly Notices of the Royal Astronomical Society, 369(1), 272 -280. https://doi.org/10.1111/j.1365-2966.2006.10299.x

We present new K- and L'-band imaging observations for members of the young (3-5 Myr) sigma Orionis cluster, obtained with UIST at UKIRT. We determine (K-L') colour excesses with respect to the photospheres, finding evidence for warm circumstellar du... Read More about Circumstellar discs in the young σ Orionis cluster.

Synthesis of the Beryllium 3131A Spectral Region (2005)
Presentation / Conference Contribution
Ashwell, J., F. Ashwell, J., Jeffries, R., D. Jeffries, R., & Smalley, B. (2005, July). Synthesis of the Beryllium 3131A Spectral Region. Paper presented at International Workshop on ATLAS12 and Related Codes: Application to Elemental Abundance Determination, Trieste, Italy

The Beryllium spectral region of the Sun, Procyon and 4 stars in the open cluster NGC6633 up to Teff = 7500K have been synthesised using ATLAS9 model atmospheres and the MOOG spectral synthesis program. The line list used for these syntheses has bee... Read More about Synthesis of the Beryllium 3131A Spectral Region.

The lithium depletion boundary in NGC 2547 as a test of pre-main-sequence evolutionary models (2005)
Journal Article
Jeffries, R. D., & Oliveira, J. M. (2005). The lithium depletion boundary in NGC 2547 as a test of pre-main-sequence evolutionary models. Monthly Notices of the Royal Astronomical Society, 358(1), 13 -29. https://doi.org/10.1111/j.1365-2966.2005.08820.x

Intermediate resolution spectroscopy from the ESO Very Large Telescope is analysed for 63 photometrically selected low-mass (0.08-0.30 Msun) candidates of the open cluster NGC 2547. We have confirmed membership for most of these stars using radial ve... Read More about The lithium depletion boundary in NGC 2547 as a test of pre-main-sequence evolutionary models.

Young stars and their circumstellar disks in the Sigma Orionis cluster (2004)
Presentation / Conference Contribution
M. Oliveira, J., D. Jeffries, R., Th. van Loon, J., & J. Kenyon, M. (2003, April). Young stars and their circumstellar disks in the Sigma Orionis cluster. Presented at Open Issues in Local Star Formation and Early Stellar Evolution, Ouro Preto, Minas Gerais, Brazil

The sigma Orionis cluster is a young association evolving under the disruptive influence of its massive O-star namesake. We are analysing this cluster as part of a program to characterise the influence of O-stars on the early stages of stellar evolut... Read More about Young stars and their circumstellar disks in the Sigma Orionis cluster.

An L'-band survey for circumstellar discs around low-mass stars in the young σ Orionis cluster (2004)
Journal Article
Jeffries, R., Oliveira, J., & Van Loon, J. (2004). An L'-band survey for circumstellar discs around low-mass stars in the young σ Orionis cluster. Monthly Notices of the Royal Astronomical Society, 347(4), 1327 -1336. https://doi.org/10.1111/j.1365-2966.2004.07315.x

We present new K- and L'-band imaging of a representative sample of members of the young 3-5 Myr old sigma Orionis cluster. We identified objects with (K-L') excess by analysing colour-colour diagrams and comparing the observations with empirical mai... Read More about An L'-band survey for circumstellar discs around low-mass stars in the young σ Orionis cluster.