A5023934472- Stellar, planetary, and galactic studies
- Galaxies: Formation, Evolution, Phenomena
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- History and Developments in Astronomy
- Cosmology and Gravitation Theories
- Astro and Planetary Science
- Geomagnetism and Paleomagnetism Studies
- Soil and Environmental Studies
- Geological Studies and Exploration
- Atmospheric Ozone and Climate
- Astrophysics and Cosmic Phenomena
- Methane Hydrates and Related Phenomena
- Space Exploration and Technology
- Cephalopods and Marine Biology
Leibniz Institute for Astrophysics Potsdam
2022-2024
Instituto de Astrofísica de Canarias
2018-2023
Universidad de La Laguna
2018-2023
Leibniz Association
2021
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 present the star cluster catalogs for 17 dwarf and irregular galaxies in $HST$ Treasury Program "Legacy ExtraGalactic UV Survey" (LEGUS). Cluster identification photometry this subsample are similar to that of entire LEGUS sample, but special methods were developed provide robust with accurate fluxes due low statistics. The colors ages largely consistent two widely used aperture corrections, a significant fraction clusters more compact than average training cluster. However, ensemble...
We use Gaia DR2 systemic proper motions of 45 satellite galaxies to constrain the mass Milky Way using scale free estimator Watkins et al. (2010). first determine anisotropy parameter $β$, and tracer satellites' radial density index $γ$ be $β$=$-0.67^{+0.45}_{-0.62}$ $γ=2.11\pm0.23$. When we exclude possible former satellites Large Magellanic Cloud, changes $β$=$-0.21^{+0.37}_{-0.51}$. find that Way's gravitational potential $α$, which is dependent on itself, with largest impact...
A wealth of tiny galaxies populates the surroundings Milky Way. Some these objects might have their origin as former satellites Large Magellanic Cloud. Examples importance understanding how many systems are genuine MW or LMC implications that number and mass function for dark matter theories treatment baryonic physics in simulations structure formation. Here we aim at deriving bulk motions estimates internal velocity dispersion metallicity properties four recently discovered distant southern...
Aims. We explore correlations between the strength of metallicity gradients in Local Group dwarf galaxies and their stellar mass, star formation history timescales, environment. Methods. performed a homogeneous analysis literature spectroscopic data red giant stars determined radial profiles for 30 galaxies. This is largest compilation this type to date. Results. The our sample show variety profiles, most them decreasing with radius some rather steep profiles. derived as function half-light...
Context. The system of galaxies around NGC 4490 was recently highlighted to display a flattened, kinematically correlated structure reminiscent planes satellite other hosts. Aims. Since known are in tension with expectations from cosmological simulations the Λ cold dark matter (ΛCDM) model, we aim quantitatively assess for first time posed by system. Methods. We measured on-sky flattening as major-to-minor axis ratio b / distribution and their line-of-sight kinematic correlation. Analogs...
The Sextans dwarf spheroidal galaxy has been challenging to study in a comprehensive way as it is highly extended on the sky, with an uncertain but large tidal radius of between $80--160$ arcminutes (or $3--4kpc), and extremely low central surface brightness Σ_V ∼ 26.2$ mag/arcsec^2. Here, we present new homogeneous survey 41 VLT/FLAMES multi-fibre spectroscopic pointings that contain 2108 individual spectra, combined photometry astrometry measurements for 333 red giant branch stars are...
The Sextans dwarf spheroidal galaxy has been challenging to study in a comprehensive way as it is highly extended on the sky, with an uncertain but large tidal radius of between 80-160 arcminutes (or 3-4kpc), and extremely low central surface brightness SigmaV = 26.2 mag/arcsec2. Here we present new homogeneous survey 41 VLT/FLAMES multi-fibre spectroscopic pointings that contain 2108 individual spectra, combined Gaia DR3 photometry astrometry v-los measurements for 333 Red Giant Branch...
Abstract The reflex motion and distortion of the Milky Way (MW) halo caused by infall a massive Large Magellanic Cloud (LMC) has been demonstrated to result in an excess orbital poles dark matter particles toward LMC pole. This was suggested help explain observed preference MW satellite galaxies coorbit along Vast Polar Structure (VPOS). We test this idea correcting positions velocities satellites for Galactocentric-distance-dependent shifts inferred from LMC-infall simulation. While should...
Context. It has been observed that several Milky Way (MW) satellite dwarf galaxies are distributed along a coherent planar distribution known as the vast polar structure (VPOS). Aims. Here we investigate whether MW satellites located on VPOS have different physical and orbital properties from those not associated with it. Methods. Using proper motion measurements of Gaia mission literature values for their observational parameters, first discriminate between systems may or be VPOS, then...
In order to minimize environmental effects and gain an insight into the internal mechanisms that shape properties of early-type dwarf systems, we study one few isolated spheroidal galaxies (dSphs) Local Group (LG): Cetus. We obtained VLT/FORS2 spectra ($R\sim2600$) in region nIR CaII triplet lines for 80 candidate red giant branch stars. The analysis yielded line-of-sight velocities metallicities ([Fe/H]) 54 bona fide member kinematic shows Cetus is a mainly pressure-supported ($\sigma_v =...
We present a detailed study of the variable star population Eridanus II (Eri II), an ultra-faint dwarf galaxy that lies close to Milky Way virial radius. analyze multi-epoch $g,r,i$ ground-based data from Goodman and Dark Energy Camera, plus $F475W, F606W, F814W$ space Advanced Camera for Surveys. report detection 67 RR Lyrae (RRL) stars 2 Anomalous Cepheids, most them new discoveries. With RRL stars, we measure distance modulus Eri II, $\mu_0=22.84\pm 0.05$ mag (D$_{\odot}=370\pm9$ kpc)...
Context. Within $\Lambda$ Cold Dark Matter ($\Lambda$CDM) simulations, Milky Way-like galaxies accrete some of their satellite in groups 3-5 members rather than individually. It was also suggested that this might be the reason behind origin planes. Objects accreted are expected to share similar specific total energy and angular momentum, identical orbital planes directions. Aims. Looking at observations Way satellites, dwarf Leo II, IV, V, Crater star cluster 1 were proposed a vestige group...
Dwarf galaxies found in isolation the Local Group (LG) are unlikely to have interacted with large LG spirals, and therefore environmental effects should not be main drivers of their evolution. We aim provide insight into internal mechanisms shaping dwarf by increasing our knowledge properties isolated systems. focus on evolved stellar component Aquarius dwarf, whose kinematic metallicity only recently started explored. obtained spectroscopic data near-infrared CaII triplet lines region FORS2...
The kinematics and chemical composition of stellar populations different ages provide crucial information about the evolution a galaxy. We aim to such for IC 1613, an isolated, gas-rich, star-forming dwarf galaxy in Local Group. present here results new spectroscopic study performed with MUSE, integral-field spectrograph on Very Large Telescope. extracted from data cubes more than 2000 sources which we separated objects further analysis. quality set allowed us obtain accurate classifications...
Context. Isolated local group (LG) dwarf galaxies have evolved most or all of their life unaffected by interactions with the large LG spirals and therefore offer opportunity to learn about intrinsic characteristics this class objects. Aims. Our aim is explore internal kinematic metallicity properties one three isolated early-type galaxies, Tucana spheroidal. This an intriguing system, as it has been found in literature rotation up 16 km s −1 , a much higher velocity dispersion than...
Supernovae feedback driven expansion has proven to be a viable mechanism explain the average properties of Ultra Diffuse Galaxies (UDGs) such as sizes, colors, mass and internal kinematics. Here, we explore origin stellar metallicity gradients in simulated UDGs from NIHAO project compare them with observed distribution both Local Group dwarfs well recently UDG DF44. Simulated display large variety profiles, showing flat negative gradients, similarly what is LG dwarfs, while DF44 data suggest...
The reflex motion and distortion of the Milky Way (MW) halo caused by infall a massive Large Magellanic Cloud (LMC) has been demonstrated to result in an excess orbital poles dark matter particles towards LMC pole. This was suggested help explain observed preference MW satellite galaxies co-orbit along Vast Polar Structure (VPOS). We test this idea correcting positions velocities satellites for Galactocentric-distance-dependent shifts inferred from LMC-infall simulation. While should...
Aims.We explore correlations between the strength of metallicity gradients in Local Group dwarf galaxies and their stellar mass, star formation history timescales, environment.Methods.We performed a homogeneous analysis literature spectroscopic data red giant stars determined radial profiles for 30 galaxies.This is largest compilation this type to date.Results.The our sample show variety profiles, most them decreasing with radius some rather steep profiles.The derived as function half-light...
It has been observed that several Milky Way (MW) satellite dwarf galaxies are distributed along a coherent planar distribution known as the Vast Polar Structure (VPOS). Here we investigate whether MW satellites located on VPOS have different physical and orbital properties from those not associated with it. Using proper motion measurements of \textit{Gaia} mission literature values for their observational parameters, first discriminate between systems may or be VPOS, then compare chemical...
Abstract We report the serendipitous discovery of a high-excitation nebula in Local Group dwarf galaxy IC 1613. The shows spectral features typical planetary (PN), but its physical size makes it an order magnitude larger than observed for this type object, if indeed belongs to hypothesise that may be example over-luminous PN, still unexplained phenomenon deserves further investigation.
Context. Within Λ cold dark matter (ΛCDM) simulations, Milky Way-like galaxies accrete some of their satellite in groups 3–5 members rather than individually, and this has been suggested as a possible mechanism driving the formation planes. Objects accreted are expected to share similar specific total energy angular momentum, also have identical orbital planes directions. Aims. Looking at observatio ns Way satellites, dwarf Leo II, IV, V, Crater star cluster 1 were proposed be vestige group...
The galaxy system around NGC4490 was recently highlighted to display a flattened, kinematically correlated structure reminiscent of satellite planes other hosts. Since known are in tension with $\Lambda$CDM expectations from cosmological simulations, we quantitatively assess for the first time posed by system. We measure on-sky flattening as major-to-minor axis ratio b/a distribution and their line-of-sight kinematic correlation. Analogs selected IllustrisTNG-50 simulation correlation...
Context. The kinematics and chemical composition of stellar populations different ages provide crucial information on the evolution various components a galaxy. Aim. Our aim is to determine individual stars as function age in IC 1613, star-forming, gas-rich, isolated dwarf galaxy Local Group (LG). Methods. We present results new spectroscopic survey 1613 conducted with MUSE, an integral field spectrograph mounted Very Large Telescope. extracted ∼2000 sources, from which we separated objects...