A5088754908- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Astrophysical Phenomena and Observations
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- Astronomical and nuclear sciences
- Methane Hydrates and Related Phenomena
- Historical and Architectural Studies
- Cosmology and Gravitation Theories
- Atmospheric Ozone and Climate
- Cryospheric studies and observations
- Spectroscopy and Chemometric Analyses
- Satellite Image Processing and Photogrammetry
- Spacecraft and Cryogenic Technologies
- Spectroscopy and Laser Applications
- Impact of Light on Environment and Health
- Historical Astronomy and Related Studies
- Archaeology and ancient environmental studies
- Scientific Research and Discoveries
Max Planck Institute for Astronomy
2015-2024
Université de Strasbourg
2015-2024
Centre National de la Recherche Scientifique
2015-2024
Observatoire astronomique de Strasbourg
2015-2024
AlbaNova
2023
Stockholm University
2023
Hospital Piñero
2022
Max Planck Society
2007-2019
Franche-Comté Électronique Mécanique Thermique et Optique - Sciences et Technologies
2019
Herzberg Institute of Astrophysics
2016-2017
We present a three-dimensional map of interstellar dust reddening, covering three-quarters the sky out to distance several kiloparsecs, based on Pan-STARRS 1 (PS1) and 2MASS photometry. The reveals wealth detailed structure, from filaments large cloud complexes. has hybrid angular resolution, with most at an resolution –, maximum . distribution is determined in fully probabilistic framework, yielding uncertainty reddening along each line sight, as well stellar distances, reddenings,...
We present a new 3D map of interstellar dust reddening, covering three quarters the sky (declinations δ ≳ −30°) out to distance several kiloparsecs. The is based on high-quality stellar photometry 800 million stars from Pan-STARRS 1 and 2MASS. divide into sightlines containing few hundred each, then infer distances types, along with line-of-sight distribution. Our incorporates more accurate average extinction law an additional 1.5 yr data, tracing greater extinctions at higher angular...
We derive the structural parameters of recently discovered very low luminosity Milky Way satellites through a Maximum Likelihood algorithm applied to SDSS data. For each satellite, even when only few tens stars are available down flux limit, yields robust estimates and errors for centroid, position angle, ellipticity, exponential half-light radius number member stars. This latter parameter is then used in conjunction with stellar population models their absolute magnitudes masses, accounting...
We present a deep photometric survey of the Andromeda galaxy, conducted with wide-field cameras CFHT and INT, that covers inner 50 kpc galaxy southern quadrant out to ~150 includes an extension M33 at >200 kpc. This is first systematic panoramic study this very outermost region galaxies. detect multitude large-scale structures low surface brightness, including several streams, two new relatively luminous (MV ∼ − 9) dwarf galaxies: And XV XVI. Significant variations in stellar populations due...
We present a precise photometric calibration of the first 1.5 years science imaging from Pan-STARRS1 survey (PS1), an ongoing optical entire sky north declination −30° in five bands. Building on techniques employed by Padmanabhan et al. Sloan Digital Sky Survey (SDSS), we use repeat PS1 observations stars to perform relative each its bands, simultaneously solving for system throughput, atmospheric transparency, and large-scale detector flat field. Both internal consistency tests comparison...
We present an analysis of the large-scale structure halo Andromeda galaxy, based on Pan-Andromeda Archeological Survey (PAndAS), currently most complete map resolved stellar populations in any galactic halo. Despite presence copious substructures, global follow closely power-law profiles that become steeper with increasing metallicity. divide sample into stream-like and a smooth component (defined as population cannot be spatially distinct substructures PAndAS). Fitting three-dimensional...
ABSTRACT The dust extinction curve is a critical component of many observational programs and an important diagnostic the physics interstellar medium. Here we present new measurements its variation toward tens thousands stars, hundred-fold larger sample than in existing detailed studies. We use data from APOGEE spectroscopic survey combination with ten-band photometry Pan-STARRS1, Two Micron All-Sky Survey, Wide-field Infrared Survey Explorer . find that optical through infrared well...
We present the discovery of three new Milky Way satellites from our search for compact stellar overdensities in photometric catalog Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS 1, or PS1) 3pi survey. The first satellite, Laevens 3, is located at a heliocentric distance d=67+/-3 kpc. With total magnitude Mv=-4.4+/-0.3 half-light radius rh=7+/-2 pc, its properties resemble those outer halo globular clusters. second system, Draco II/Laevens 4 (Dra II), closer fainter...
We present the Pristine survey, a new narrow-band photometric survey focused on metallicity-sensitive Ca H & K lines and conducted in northern hemisphere with wide-field imager MegaCam Canada-France-Hawaii Telescope (CFHT). This paper reviews our overall strategy discusses data processing metallicity calibration. Additionally we review application of these to main aims which are gather large sample most metal-poor stars Galaxy, further characterise faintest Milky Way satellites, map...
Distance measurements to molecular clouds are important but often made separately for each cloud of interest, employing very different data and techniques. We present a large, homogeneous catalog distances clouds, most which unprecedented accuracy. determine using optical photometry stars along lines sight toward these obtained from PanSTARRS-1. simultaneously infer the reddenings stars, tracking full probability distribution function technique presented in Green et al. fit star-by-star...
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...
Abstract We present the discovery of Ursa Major III/UNIONS 1, least luminous known satellite Milky Way, which is estimated to have an absolute V -band magnitude <?CDATA $+{2.2}_{-0.3}^{+0.4}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>+</mml:mo> <mml:msubsup> <mml:mrow> <mml:mn>2.2</mml:mn> </mml:mrow> <mml:mo>−</mml:mo> <mml:mn>0.3</mml:mn> <mml:mn>0.4</mml:mn> </mml:msubsup> </mml:math> mag, equivalent a total stellar mass ${16}_{-5}^{+6}$?>...
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>...
Abstract Interpretation of data from faint dwarf galaxies is made challenging by observations limited to only the brightest stars. We present a major improvement tackle this challenge undertaking zoomed cosmological simulations that resolve evolution all individual stars more massive than 0.5 M ⊙ , thereby explicitly tracking observable for Hubble time. For first time, we predict color–magnitude diagrams and spatial distribution ≈100,000 within four ( ⋆ ≈ 10 5 ) directly their initial...
We present an analysis of the asymmetries in population Galactic M-giant stars 2MASS All Sky catalogue. Several large-scale are detected, most significant which is a strong elliptical-shaped stellar over-density, close to plane at (l=240, b=-8), constellation Canis Major. A small grouping globular clusters (NGC 1851, NGC 1904, 2298, and 2808), coincident position radial velocity, surround this structure, as do number open clusters. The over-density similar that core Sagittarius dwarf galaxy....
[abridged] We present the results of a spectroscopic survey recently discovered faint Milky Way satellites Boo, UMaI, UMaII and Wil1. Using DEIMOS spectrograph on Keck, we have obtained samples that contain from 15 to 85 probable members these for which derive radial velocities precise few km/s down i~21-22. About half stars are observed with high enough S/N estimate their metallicity within \pm0.2 dex. From this dataset, show is only object does not clear velocity peak. However, measured...
We present the results of a thorough study nucleus Sgr dwarf spheroidal galaxy (Sgr dSph) and bright globular cluster M54 (NGC 6715) that resides within same (Sgr,N). have obtained accurate radial velocities metallicity estimates for 1152 candidate red giant branch stars lying ∼9' from center galaxy, Keck/DEIMOS VLT/FLAMES spectra infrared Ca ii triplet. Using both velocity information we selected two samples 425 321 very likely members Sgr,N, respectively. The considered systems display...
We map the stellar structure of Galactic thick disk and halo by applying color-magnitude diagram (CMD) fitting to photometric data from SEGUE survey, allowing, for first time, a comprehensive analysis their at both high low latitudes using uniform SDSS photometry. Incorporating photometry all relevant stars simultaneously, CMD bypasses need choose single tracer populations. Using old populations differing metallicities as templates we obtain sparse 3D mass distribution |Z|>1 kpc. Fitting...
We present a homogeneous kinematic analysis of red giant branch stars within 18 the 28 Andromeda dwarf spheroidal (dSph) galaxies, obtained using Keck I LRIS and II DEIMOS spectrographs. Based on their g-i colors (taken with CFHT MegaCam imager), physical positions sky, radial velocities, we assign probabilities dSph membership to each observed star. Using this information, velocity dispersions, central masses densities dark matter halos are calculated for these objects, compared properties...
We present the discovery of five new dwarf galaxies, Andromeda XXIII–XXVII, located in outer halo M31. These galaxies were discovered during second year data from Pan-Andromeda Archaeological Survey (PAndAS), a photometric survey M31/M33 subgroup conducted with MegaPrime/MegaCam wide-field camera on Canada–France–Hawaii Telescope. The current PAndAS now provides an almost complete panoramic view M31 out to average projected radius ∼150 kpc. Here we for first time metal-poor stellar density...
In `A Bayesian Approach to Locating the Red Giant Branch Tip Magnitude (PART I),' a new technique was introduced for obtaining distances using TRGB standard candle. Here we describe useful complement with potential further reduce uncertainty in our distance measurements by incorporating matched-filter weighting scheme into model likelihood calculations. this scheme, stars are weighted according their probability of being true object members. We then re-test modified algorithm...
We present a panoramic map of the stellar streams Milky Way based upon astrometric and photometric measurements from Gaia DR2 catalogue. In this first contribution, we concentrate on halo at heliocentric distances beyond 5 kpc, Galactic latitudes $|b|>30\deg$, using STREAMFINDER algorithm to detect structures along plausible orbits that are consistent with proper motion measurements. find rich network criss-crossing in halo. Some these were previously-known, several new discoveries, but...