A5078813892- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Spectroscopy and Chemometric Analyses
- Dark Matter and Cosmic Phenomena
- Solar and Space Plasma Dynamics
- Astronomical and nuclear sciences
- Mechanical and Optical Resonators
- Natural Language Processing Techniques
- Cosmology and Gravitation Theories
- Linguistics and Discourse Analysis
- Scientific Research and Discoveries
- Advanced Chemical Sensor Technologies
- Water Quality Monitoring and Analysis
- Archaeology and ancient environmental studies
- Analytical Chemistry and Sensors
- Geophysics and Gravity Measurements
- Spectroscopy and Laser Applications
- Force Microscopy Techniques and Applications
- linguistics and terminology studies
- Astrophysical Phenomena and Observations
Instituto de Astrofísica de Canarias
2020-2024
Universidad de La Laguna
2021-2024
Centre National de la Recherche Scientifique
2016-2023
Tallinn University of Technology
2023
Nanomatériaux Pour les Systèmes Sous Sollicitations Extrêmes
2023
Institut Franco-Allemand de Recherches de Saint-Louis
2023
University of Toronto
2022
Herzberg Institute of Astrophysics
2018-2021
Université de Bourgogne
2019
Laboratoire Interdisciplinaire Carnot de Bourgogne
2019
The Milky Way halo was predominantly formed by the merging of numerous progenitor galaxies. However, our knowledge this process is still incomplete, especially in regard to total number mergers, their global dynamical properties and contribution stellar population Galactic halo. Here, we uncover mergers detecting groupings globular clusters, streams satellite galaxies action ($\mathbf{J}$) space. While actions fully characterize orbits, additionally use redundant information on energy...
WEAVE, the new wide-field, massively multiplexed spectroscopic survey facility for William Herschel Telescope, will see first light in late 2022. WEAVE comprises a 2-degree field-of-view prime-focus corrector system, nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini' integral field units (IFUs), and single large IFU. These systems feed dual-beam spectrograph covering wavelength range 366$-$959\,nm at $R\sim5000$, or two shorter ranges $R\sim20\,000$. After summarising...
Abstract We present an atlas and follow-up spectroscopic observations of 87 thin stream-like structures detected with the STREAMFINDER algorithm in Gaia DR3, which 28 are new discoveries. Here, we focus on using these streams to refine mass models Galaxy. Fits a double-power-law halo outer power-law slope set − β h = −3 yield inner <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>−</mml:mo> <mml:msub> <mml:mi>γ</mml:mi> <mml:mi>h</mml:mi> </mml:msub>...
The Pan-Andromeda Archaeological Survey is a survey of $>400$ square degrees centered on the Andromeda (M31) and Triangulum (M33) galaxies that has provided most extensive panorama $L_\star$ galaxy group to large projected galactocentric radii. Here, we collate summarise current status our knowledge substructures in stellar halo M31, discuss connections between these features. We estimate 13 distinctive were produced by at least 5 different accretion events, all last 3 or 4 Gyrs. suggest few...
We perform a comprehensive determination of the systemic proper motions 74 dwarf galaxies and galaxy candidates in Local Group based on Gaia early data release 3. The outputs analysis for each galaxy, including probabilities membership, will be made publicly available. is augmented by orbital properties within 500 kpc. adopt flexible Bayesian methodology presented McConnachie \& Venn (2020), which takes into account location stars sky, colour-magnitude diagram motion plane. apply some...
We used the spectro-photometric information of ∼219 million stars from Gaia ’s Data Release 3 (DR3) to calculate synthetic, narrowband, metallicity-sensitive CaHK magnitudes that mimic observations Pristine survey, a survey photometric metallicities Milky Way has been mapping more than 6500 deg 2 northern sky with Canada–France–Hawaii Telescope since 2015. These synthetic were for an absolute recalibration deeper photometry and, combined broadband information, and estimate over whole sky....
The Canada-France Imaging Survey (CFIS) will map the northern high Galactic latitude sky in $u$-band ("CFIS-u", 10,000$\, {\rm deg^2}$) and $r$-band ("CFIS-r", 5,000$\, deg^2}$), enabling a host of stand-alone science investigations, providing some ground-based data necessary for photometric redshift determination Euclid mission. In this first contribution we present component survey, describe observational strategy, discuss highlight results, based on approximately one third final area. We...
ABSTRACT Our Galaxy is known to contain a central boxy/peanut-shaped bulge, yet the importance of classical, pressure-supported component within part Milky Way still being debated. It should be most visible at low metallicity, regime that has not been studied in detail. Using metallicity-sensitive narrow-band photometry, Pristine Inner Survey (PIGS) collected large sample metal-poor ($\rm {[Fe/H]}\, \lt -1.0$) stars inner address this open question. We use PIGS trace kinematics as function...
We present the results of a 3-year long, medium-resolution spectroscopic campaign aimed at identifying very metal-poor stars from candidates selected with CaHK, metallicity-sensitive Pristine survey. The catalogue consists total 1007 stars, and includes 146 rediscoveries already presented in previous surveys, 707 new [Fe/H] < -2.0, 95 extremely -3.0. provide for every star catalogue, [C/Fe] measurements subset (10% -3 24% -2) which carbon determination is possible, contingent mainly on...
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 discover 28 new bright (V < 15) with [Fe/H]0, and a star very low [Mg/Fe]. The kinematics orbits for all highly probable candidates are determined by combining our precision radial velocities Gaia DR2 proper motions. Some show unusual their chemistries, including planar orbits, unbound elliptical...
ABSTRACT The Pristine survey uses narrow-band photometry to derive precise metallicities down the extremely metal-poor regime ($ \rm [Fe/H] \lt -3$), and currently consists of over 4 million FGK-type stars a sky area $\sim 2500\, \mathrm{deg}^2$. We focus our analysis on subsample ∼80 000 main-sequence turn-off with heliocentric distances between 6 20 kpc, which we take be representative sample inner halo. resulting metallicity distribution function (MDF) has peak at $ =-1.6$, slope...
We reconsider the case for association of Galactic globular clusters (GCs) to tidal stream Sagittarius dwarf spheroidal galaxy (Sgr dSph), using Gaia DR2 data. use RR Lyrae trace in 6D and we select matching observed position velocity. In addition residing main body (M 54, Ter 8, 7, Arp 2) confirm membership Pal 12 Whiting 1 portion trailing arm populated by stars lost during recent perigalactic passages. NGC 2419, 5634 4147 are very interesting candidates, possibly associated more ancient...
After their birth a significant fraction of all stars pass through the tidal threshold (prah) cluster origin into classical tails. The asymmetry between number in leading and trailing tails tests gravitational theory. All five open clusters with tail data (Hyades, Praesepe, Coma Berenices, COIN-Gaia 13, NGC 752) have visibly more within dcl = 50 pc centre than tail. Using Jerabkova-compact-convergent-point (CCP) method, extended been mapped out for four nearby 600-2000 Myr old to dcl>50 pc....
We use the photometric metallicities provided by panoramic Pristine survey to study veracity and derive of numerous stellar streams found application STREAMFINDER algorithm Gaia EDR3 data. All 26 present in show a clear metallicity distribution function, which provides an independent check reality these structures, supporting reliability finding power measure precise metallicities. further 6 candidate structures with coherent phase-space signals that are very likely streams. The majority...
The emergence of the disc in our Galaxy and relation thick thin formation evolution is still a matter debate. chemo-dynamical characterization stars key to resolve this question, particular at parameter regimes where both components overlap, such as region around [Fe/H] $\sim$ $-0.7$ corresponding metal-poor end. In paper we re-assess recent detection extension moving with thin-disc-like rotational velocities between -2 < -0.7 that was made based on metallicity estimates obtained from...
We present the first full six-dimensional panoramic portrait of Sagittarius stream, obtained by searching for wide stellar streams in Gaia DR2 dataset with STREAMFINDER algorithm. use kinematic behavior sample to devise a selection RR Lyrae, providing excellent distance measurements along stream. The proper motion data are complemented radial velocities from public surveys. find that global morphological and properties stream still reasonably well reproduced simple Law & Majewski (2010)...
Metal-poor stars are important tools for tracing the early history of Milky Way, and learning about first generations stars. Simulations suggest that oldest metal-poor to be found in inner Galaxy. Typical bulge surveys, however, lack low metallicity ([Fe/H] < -1.0) because Galaxy is predominantly metal-rich. The aim Pristine Inner Survey (PIGS) study very (VMP, [Fe/H] -2.0) this region. In PIGS, targets spectroscopic follow-up selected from metallicity-sensitive CaHK photometry CFHT. This...
High-resolution optical spectra of 30 metal-poor stars selected from the \Pristine\ survey are presented, based on observations taken with Gemini Observatory GRACES spectrograph. Stellar parameters \teff and \logg determined using a Gaia DR2 colour-temperature calibration surface gravity Stefan-Boltzmann equation. used to determine chemical abundances (or upper-limits) for 20 elements (Li, O, Na, Mg, K, Ca, Ti, Sc, Cr, Mn, Fe, Ni, Cu, Zn, Y, Zr, Ba, La, Nd, Eu). These confirmed be...
We present a new spectroscopic study of the dwarf galaxy Bootes I (Boo I) with data from Anglo-Australian Telescope and its AAOmega spectrograph together Two Degree Field multi-object system. observed 36 high-probability Boo stars selected using Gaia Early Data Release 3 proper motions photometric metallicities Pristine survey. Out those, 27 are found to be I's stars, resulting in an excellent success rate 75% at finding members. Our analysis uses pipeline developed estimate radial...
The Pristine- Gaia synthetic catalogue of reliable photometric metallicities makes use spectrophotometric information from DR3 XP spectra to calculate metallicity-sensitive CaHK magnitudes, which in turn provides for ∼30 million FGK stars using the Pristine survey model and survey's training sample. We performed first low- medium-resolution spectroscopic follow-up bright (G<15) distant (upto 35 kpc) very extremely metal-poor (V/EMP Fe/H <-2.5) red giant branch this catalogue--to...
Abstract Stellar streams in the Milky Way are promising detectors of low-mass dark matter (DM) subhalos predicted by ΛCDM. Passing induce perturbations that indicate presence subhalos. Understanding how known DM-dominated satellites impact is a crucial step toward using stream to constrain properties perturbers. Here, we cross-match Gaia Early Data Release 3 and SEGUE member catalog Cetus-Palca (CPS) with H3 for additional radial velocity measurements fit orbit CPS this six-dimensional (6D)...
Abstract We present ∼115 new spectroscopically identified members of the GD-1 tidal stream observed with 5000-fiber Dark Energy Spectroscopic Instrument (DESI). confirm existence a “cocoon,” which is broad (FWHM ∼ 2 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover> <mml:mrow> <mml:mo>.</mml:mo> </mml:mrow> <mml:mtext>°</mml:mtext> </mml:mover> </mml:math> 932 460 pc) and kinematically hot (velocity dispersion, σ 5–8 km s −1 ) component that surrounds...
Kinematically cold tidal streams of globular clusters (GC) are excellent tracers the Galactic gravitational potential at moderate Galactocentric distances, and can also be used as probes law gravity on scales. Here, we compare for first time generation such in Newtonian Milgromian (MOND). We compute analytical results to investigate expected shape GC both frameworks, then run N-body simulations with Phantom Ramses code. find that GCs tend become lopsided MOND. This is a consequence external...
Tidal streams of disrupting dwarf galaxies orbiting around their host galaxy offer a unique way to constrain the shape galactic gravitational potentials. Such can be used as leaning tower experiments on scales. The most well motivated modification gravity proposed an alternative dark matter scales is Milgromian dynamics (MOND), and we present here first ever N-body simulations dynamical evolution Sagittarius in this framework. Using realistic baryonic mass model for Milky Way, attempt...