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Constraining churning and blurring in the Milky Way using large spectroscopic surveys - an exploratory study
Bowers, J. Bradley; Feltzing, Sofia; Agertz, Oscar
We have investigated the possibilities to quantify how much stars move in the Milky Way disc due to diffuse processes (blurring) and due to influences from spiral arms and the bar (churning). We assume that the formation radius of a star can be inferred if we know its elemental abundances and age and the metallicity profile of the interstellar med…
Seeing above the clouds with high-resolution spectroscopy
Gandhi, Siddharth; Brogi, Matteo; Webb, Rebecca K.
In the last decade, ground-based high-resolution Doppler spectroscopy (HRS) has detected numerous species in transiting and non-transiting hot Jupiters, and is ideally placed for atmospheric characterization of warm Neptunes and super Earths. Many of these cooler and smaller exoplanets have shown cloudy atmospheres from low-resolution near-infrare…
Gamma-Ray Emission of 60Fe and 26Al Radioactivity in Our Galaxy
Greiner, J.; Wang, W.; Siegert, T. +7 more
The isotopes 60Fe and 26Al originate from massive stars and their supernovae, reflecting ongoing nucleosynthesis in the Galaxy. We studied the gamma-ray emission from these isotopes at characteristic energies 1173, 1332, and 1809 keV with over 15 yr of SPI data, finding a line flux in 60Fe combined lines of $(0.31\…
The Formation of a Stellar Association in the NGC 7000/IC 5070 Complex: Results from Kinematic Analysis of Stars and Gas
Hillenbrand, Lynne A.; Carpenter, John M.; Kuhn, Michael A. +1 more
We examine the clustering and kinematics of young stellar objects (YSOs) in the North America/Pelican Nebulae, as revealed by Gaia astrometry, in relation to the structure and motions of the molecular gas, as indicated in molecular-line maps. The Gaia parallaxes and proper motions allow us to significantly refine previously published lists of YSOs…
Differential abundances of open clusters and their tidal tails: Chemical tagging and chemical homogeneity
Casamiquela, L.; Soubiran, C.; Heiter, U. +4 more
Context. Well studied open clusters (OCs) of the solar neighborhood are frequently used as reference objects to test galactic and stellar theories. For that purpose, their chemical composition needs to be known with a high level of confidence. It is also important to clarify if each OC is chemically homogeneous and if it has a unique chemical sign…
Outstanding Challenges of Exoplanet Atmospheric Retrievals
Barstow, Joanna K.; Heng, Kevin
Spectral retrieval has long been a powerful tool for interpreting planetary remote sensing observations. Flexible, parameterised, agnostic models are coupled with inversion algorithms in order to infer atmospheric properties directly from observations, with minimal reliance on physical assumptions. This approach, originally developed for applicati…
NGTS-11 b (TOI-1847 b): A Transiting Warm Saturn Recovered from a TESS Single-transit Event
Henning, Thomas; Jordán, Andrés; Espinoza, Néstor +38 more
We report the discovery of NGTS-11 b (=TOI-1847b), a transiting Saturn in a 35.46 day orbit around a mid K-type star ( ${T}_{\mathrm{eff}}$ = 5050 ± 80 K). We initially identified the system from a single-transit event in a TESS full-frame image light curve. Following 79 nights of photometric monitoring with an NGTS telescope, we observed a second…
Stellar Properties of z ≳ 8 Galaxies in the Reionization Lensing Cluster Survey
Ouchi, Masami; Mahler, Guillaume; Frye, Brenda L. +18 more
Measurements of stellar properties of galaxies when the universe was less than one billion years old yield some of the only observational constraints on the onset of star formation. We present here the inclusion of Spitzer/IRAC imaging in the fitting of the spectral energy distribution of the seven highest-redshift galaxy candidates selected from …
Mapping the Galactic disc with the LAMOST and Gaia red clump sample: II. 3D asymmetrical kinematics of mono-age populations in the disc between 6-14 kpc
Wang, H. -F.; López-Corredoira, M.; Huang, Y. +11 more
We perform analysis of the 3D kinematics of Milky Way disc stars in mono-age populations. We focus on stars between Galactocentric distances of R = 6 and 14 kpc, selected from the combined LAMOST Data Release 4 (DR4) red clump giant stars and Gaia DR2 proper motion catalogue. We confirm the 3D asymmetrical motions of recent works and provide time …
A Well-aligned Orbit for the 45 Myr-old Transiting Neptune DS Tuc Ab
Butler, R. P.; Crane, J. D.; Teske, J. K. +18 more
DS Tuc Ab is a Neptune-sized planet that orbits around a G star in the 45 Myr old Tucana-Horologium moving group. Here, we report the measurement of the sky-projected angle between the stellar spin axis and the planet's orbital axis, based on the observation of the Rossiter-McLaughlin effect during three separate planetary transits. The orbit appe…