33 citations · 158 across the 27 of their papers we have counts for
27 papers
Chemodynamical evidence of the HR 1614 moving group as a bar resonance
Andreas J. Koch-Hansen, Vladislav Gulaev, Dominik H. Plonka +4
Moving groups (MGs) are ensembles of disk stars that clump in velocity and action space. A multitude of explanations as to their origin has been attempted, from dissolved star clus…
Chemical signatures of planetary systems in their host stars. Near-infrared spectroscopy of four planet-hosting wide binaries
Dongwook Lim, Sol Yun, Andreas J. Koch-Hansen +3
An important open question in exoplanet studies is whether planets leave detectable chemical fingerprints on their host stars. While several studies have suggested possible planeta…
The Milky Way Bulge Extra-Tidal Star Survey: NGC 6569
Joanne Hughes, Andrea Kunder, Kevin Covey +25
We present spectroscopic evidence for tidal debris associated with the bulge globular cluster NGC 6569, based on medium-resolution (R ~ 11,000) Anglo-Australian Telescope spectra o…
The Galactic Bulge exploration V.: The secular spherical and X-shaped Milky Way bulge
Z. Prudil, V. P. Debattista, L. Beraldo e Silva +9
In this work, we derive systemic velocities and subsequently orbits for 8456 RR~Lyrae stars. We identify interlopers from other Milky Way (MW) structures, which amount to 22 percen…
Unlocking the mystery of Sr synthesis in the early Galaxy through analysis of barium isotopes in very metal-poor stars
T. M. Sitnova, L. Lombardo, L. I. Mashonkina +8
We determine the contributions of the rapid (r) and slow (s) neutron capture processes to the Ba isotope mixture, along with Ba, Eu, and Sr NLTE abundances, in a sample of very met…
Unevolved Li-rich stars at low metallicity: a possible formation pathway through novae
Tadafumi Matsuno, Alex Kemp, Ataru Tanikawa +7
A small fraction of low-mass stars have been found to have anomalously high Li abundances. Although it has been suggested that mixing during the red giant branch phase can lead to…
The Galactic Bulge exploration IV.: RR~Lyrae stars as traces of the Galactic bar -- 3D and 5D analysis, extinction variation
Z. Prudil, A. Kunder, L. Beraldo e Silva +10
We created new reddening maps and derived new extinction laws from visual to near-infrared passbands using improved RR~Lyrae period-absolute magnitude-metallicity relations, thus e…
Chemical Evolution of R-process Elements in Stars (CERES). III. Chemical abundances of neutron capture elements from Ba to Eu
L. Lombardo, C. J. Hansen, F. Rizzuti +11
The chemical abundances of elements such as barium and the lanthanides are essential to understand the nucleosynthesis of heavy elements in the early Universe as well as the contri…
Two stellar populations with different metallicities in the low-mass globular cluster Gran 5
Dongwook Lim, Sang-Hyun Chun, Young-Wook Lee +3
Context. With the increasing number of discoveries of globular clusters in the inner Milky Way, the need for spectroscopic confirmation and further investigation of their stellar p…
The Galactic bulge exploration II. Line-of-sight velocity templates for single-mode RR~Lyrae stars
Z. Prudil, R. Smolec, A. Kunder +2
We present a new set of tools to derive systemic velocities for single-mode RR~Lyrae stars from visual and near-infrared spectra. We derived scaling relations and line-of-sight vel…
RR Lyrae Stars Belonging to the Candidate Globular Cluster Patchick 99
Evan Butler, Andrea Kunder, Zdenek Prudil +16
Patchick 99 is a candidate globular cluster located in the direction of the Galactic bulge, with a proper motion almost identical to the field and extreme field star contamination.…
The Halos and Environments of Nearby Galaxies (HERON) Survey IV: Complexity in the boxy galaxies NGC 720 and NGC 2768
Andreas J. Koch-Hansen, Anna Pasquali, R. Michael Rich +2
The shapes of galaxies, in particular their outer regions, are important guideposts to their formation and evolution. Here we report on the discovery of strongly box-shaped morphol…
Chemical homogeneity of wide binary system: An approach from Near-Infrared spectroscopy
Dongwook Lim, Andreas J. Koch-Hansen, Seungsoo Hong +2
Wide binaries, with separations between two stars from a few AU to more than several thousand AU, are valuable objects for various research topics in Galactic astronomy. As the num…
The Galactic Bulge exploration I.: The period-absolute\,magnitude-metallicity relations for RR~Lyrae stars for , , , , , , , and passbands using DR3 parallaxes
Z. Prudil, A. Kunder, I. Dekany +1
We present a new set of period-absolute magnitude-metallicity (PMZ) relations for single-mode RR Lyrae stars calibrated for the optical , , , , near-i…
The Milky Way Bulge extra-tidal star survey: BH 261 (AL 3)
Andrea Kunder, Zdenek Prudil, Kevin Covey +19
The Milky Way Bulge extra-tidal star survey (MWBest) is a spectroscopic survey with the goal of identifying stripped globular cluster stars from inner Galaxy clusters. In this way,…
The haloes and environments of nearby galaxies (HERON) -- III. A 45 kpc spiral structure in the GLSB galaxy UGC 4599
Aleksandr V. Mosenkov, R. Michael Rich, Michael Fusco +10
We use a 0.7-m telescope in the framework of the Halos and Environments of Nearby Galaxies (HERON) survey to probe low surface brightness structures in nearby galaxies. One of our…
Blanco DECam Bulge Survey (BDBS) IV: Metallicity Distributions and Bulge Structure from 2.6 Million Red Clump Stars
Christian I. Johnson, R. Michael Rich, Iulia T. Simion +12
We present photometric metallicity measurements for a sample of 2.6 million bulge red clump stars extracted from the Blanco DECam Bulge Survey (BDBS). Similar to previous studies,…
Blanco DECam Bulge Survey (BDBS) V. Cleaning the foreground populations from Galactic bulge colour-magnitude diagrams using Gaia EDR3
Tommaso Marchetti, Christian I. Johnson, Meridith Joyce +8
The Blanco DECam Bulge Survey (BDBS) has imaged more than 200 square degrees of the southern Galactic bulge, providing photometry in the ugrizy filters for million uniqu…
Milky Way archaeology using RR Lyrae and type II Cepheids II. High velocity RR Lyrae stars, and mass of the Milky Way
Z. Prudil, A. J Koch-Hansen, B. Lemasle +10
We report the discovery of high velocity candidates among RR~Lyrae stars found in the Milky Way halo. We identified 9 RR~Lyrae stars with Galactocentric velocities exceeding the lo…
Chemodynamics of metal-poor wide binaries in the Galactic halo: Association with the Sequoia event
Dongwook Lim, Andreas J. Koch-Hansen, Camilla Juul Hansen +4
Recently, an increasing number of wide binaries has been discovered. Their chemical and dynamical properties are studied through extensive surveys and pointed observations. However…
TOPoS VI. The metal-weak tail of the metallicity distribution functions of the Milky Way and of the Gaia-Sausage-Enceladus structure
P Bonifacio, L Monaco, S Salvadori +11
Context. The TOPoS project has the goal to find and analyse Turn-Off (TO) stars of extremely low metallicity. To select the targets for spectroscopic follow-up at high spectral res…
Spectroscopic Observations of Obscured Populations in the Inner Galaxy: 2MASS-GC02, Terzan 4, and the 200 km/s stellar peak
Andrea Kunder, Riley E. Crabb, Victor P. Debattista +2
The interpretation of potentially new and already known stellar structures located at low-latitudes is hindered by the presence of dense gas and dust, as observations toward these…
NGC 1261: an -process enhanced globular cluster from the Gaia-Enceladus event
Andreas J. Koch-Hansen, Camilla Juul Hansen, Andrew McWilliam
Our Milky Way (MW) has witnessed a series of major accretion events. One of the later additions, Gaia-Enceladus, has contributed a considerable mass to the inner Galaxy, but also g…
Milky Way archaeology using RR Lyrae and type II Cepheids I. The Orphan stream in 7D using RR Lyrae stars
Z. Prudil, M. Hanke, B. Lemasle +19
We present a chemo-dynamical study of the Orphan stellar stream using a catalog of RR~Lyrae pulsating variable stars for which photometric, astrometric, and spectroscopic data are…