Publications associées à Gaia Focused Product Release: Sources from Service Interface Function image analysis Half a million new sources in omega Centauri

Gaia's brightest very metal-poor (VMP) stars Metallicity catalogue of a thousand VMP stars from Gaia's radial velocity spectrometer spectra

Context. Gaia DR3 has offered the scientific community a remarkable dataset of approximately one million spectra acquired with the radial velocity spectrometer (RVS) in the calcium II triplet region, which is well suited to identify very metal-poor (VMP) s ...

Edp Sciences S A2024

Hidden Gems on a Ring: Infant Massive Clusters and Their Formation Timeline Unveiled by ALMA, HST, and JWST in NGC 3351

Hamid Hassani, Hao He, Robin Gopala Tress, Jiayi Sun

We use 0.1 '' observations from the Atacama Large Millimeter Array (ALMA), Hubble Space Telescope (HST), and JWST to study young massive clusters (YMCs) in their embedded "infant" phase across the central starburst ring in NGC 3351. Our new ALMA data revea ...

Iop Publishing Ltd2024

Gaia Focused Product Release: Radial velocity time series of long-period variables

Stephan Morgenthaler, Shuangqing Liao

Context. The third Gaia Data Release (DR3) provided photometric time series of more than 2 million long-period variable (LPV) candidates. Anticipating the publication of full radial-velocity data planned with Data Release 4, this Focused Product Release (F ...

Edp Sciences S A2023

Gaia Data Release 3 Summary of the variability processing and analysis

Mária Süveges

Context. Gaia has been in operations since 2014, and two full data releases (DR) have been delivered so far: DR1 in 2016 and DR2 in 2018. The third Gaia data release expands from the early data release (EDR3) in 2020, which contained the five-parameter ast ...

EDP SCIENCES S A2023

The Pristine dwarf galaxy survey-V. The edges of the dwarf galaxy Hercules

Pascale Jablonka, Nicolas Lawrence Etienne Longeard

We present a new spectroscopic study of 175 stars in the vicinity of the dwarf galaxy Hercules (d similar to 132 kpc) with data from the Anglo-Australian Telescope and its AAOmega spectrograph together with the Two Degree Field multi-object system to solve ...

OXFORD UNIV PRESS2023

The extended stellar halo' of the Ursa Minor dwarf galaxy

Pascale Jablonka

Stellar candidates in the Ursa Minor (UMi) dwarf galaxy have been found using a new Bayesian algorithm applied to Gaia EDR3 data. Five of these targets are located in the extreme outskirts of UMi, from similar to 5 to 12 elliptical half-light radii (r h), ...

OXFORD UNIV PRESS2023

Crowded No More: The Accuracy of the Hubble Constant Tested with High-resolution Observations of Cepheids by JWST

Richard Irving Anderson

High-resolution James Webb Space Telescope (JWST) observations can test confusion-limited Hubble Space Telescope (HST) observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWS ...

Iop Publishing Ltd2023

The eta Aquilae System: Radial Velocities and Astrometry in Search of eta Aql B

Richard Irving Anderson

The classical Cepheid eta Aql was not included in past Leavitt Law work because of a presumed complicating orbit due to a known B9.8V companion. To determine the orbit of eta Aql B, we analyze a significant number of radial velocity (RV) measurements from ...

2022

The Pristine survey - XVI. The metallicity of 26 stellar streams around the Milky Way detected with the STREAMFINDER in Gaia EDR3

Pascale Jablonka, Carmela Lardo

We use the photometric metallicities provided by the panoramic Pristine survey to study the veracity and derive the metallicities of the numerous stellar streams found by the application of the STREAMFINDER algorithm to the Gaia Early Data Release 3 data. ...

OXFORD UNIV PRESS2022

Metallicity Distribution Function of the Eridanus II Ultra-faint Dwarf Galaxy from Hubble Space Telescope Narrowband Imaging

Nicolas Lawrence Etienne Longeard

We use deep narrowband CaHK (F395N) imaging taken with the Hubble Space Telescope (HST) to construct the metallicity distribution function (MDF) of Local Group ultra-faint dwarf galaxy Eridanus II (Eri II). When combined with archival F475W and F814W data, ...

IOP Publishing Ltd2022

The Gaia-ESO Survey: Spectroscopic-asteroseismic analysis of K2 stars in Gaia-ESO The K2 Galactic Caps Project

Carmela Lardo

Context. The extensive stellar spectroscopic datasets that are available for studies in Galactic Archeaology thanks to, for example, the Gaia-ESO Survey, now benefit from having a significant number of targets that overlap with asteroseismology projects su ...

EDP SCIENCES S A2020

Extended main sequence turnoffs in open clusters as seen by Gaia - II. The enigma of NGC 2509

Carmela Lardo

We investigate the morphology of the colour-magnitude diagram (CMD) of the open cluster NGC 2509 in comparison with other Galactic open clusters of similar age using Gaia photometry. At similar to 900 Myr Galactic open clusters in our sample all show an ex ...

OXFORD UNIV PRESS2020

Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era

Pierre North

Context. Li is extensively known to be a good tracer of non-standard mixing processes occurring in stellar interiors. Aims. We present the results of a new large Li survey in red giant stars and combine it with surveys from the literature to probe the impa ...

EDP SCIENCES S A2020

The Pristine survey - X. A large population of low-metallicity stars permeates the Galactic disc

Pierre North, Pascale Jablonka, Romain Ely Roland Lucchesi, Nicolas Lawrence Etienne Longeard

The orbits of the least chemically enriched stars open a window on the formation of our Galaxy when it was still in its infancy. The common picture is that these low-metallicity stars are distributed as an isotropic, pressure-supported component since thes ...

OXFORD UNIV PRESS2020

The Pristine survey IX. CFHT ESPaDOnS spectroscopic analysis of 115 bright metal-poor candidate stars

Pascale Jablonka, Carmela Lardo

A chemo-dynamical analysis of 115 metal-poor candidate stars selected from the narrow band Pristine photometric survey is presented based on CFHT high-resolution ESPaDOnS spectroscopy, We have discovered 28 new bright (V < 15) stars with I Fe/H]

OXFORD UNIV PRESS2020

Photometric characterization of multiple populations in star clusters: the impact of the first dredge-up

Carmela Lardo

The existence of star-to-star light-element abundance variations (multiple populations, MPs) in massive Galactic and extragalactic star clusters older than about 2 Gyr is by now well established. Photometry of red giant, branch (RGB) stars has been and sti ...

OXFORD UNIV PRESS2020

Leveraging HST with MUSE: II. Na-abundance variations in intermediate age star clusters

Carmela Lardo

Ancient (>10 Gyr) globular clusters (GCs) show chemical abundance variations in the form of patterns among certain elements, e.g. N correlates with Na and anticorrelates with O. Recently, N abundance spreads have also been observed in massive star clusters ...

OXFORD UNIV PRESS2020

The Hidden Past of M92: Detection and Characterization of a Newly Formed 17 degrees Long Stellar Stream Using the Canada-France Imaging Survey

Nicolas Lawrence Etienne Longeard

We present an analysis of the structure, kinematics, and orbit of a newly found stellar stream emanating from the globular cluster M92 (NGC 6341). This stream was discovered in an improved matched-filter map of the outer Galaxy, based on a "color-color-mag ...

IOP PUBLISHING LTD2020

Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram

Stephan Morgenthaler, Mikaël Martino, Jean-Marie Petit, Shuangqing Liao

Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G less than or similar to 21 mag. ...

EDP SCIENCES S A2019

Constant light element abundances suggest that the extended P1 in NGC 2808 is not a consequence of CNO-cycle nucleosynthesis

Carmela Lardo

Recent photometric results have identified a new population among globular cluster stars. This population, referred to as the 'extended P1', has been suggested to be the manifestation of a new abundance pattern where the initial mass fraction of He changes ...

OXFORD UNIV PRESS2019