Search Publications
Stellar Feedback on the Earliest Stage of Massive Star Formation
Chevance, M.; Stutzki, J.; Nayak, O. +7 more
We report SOFIA/GREAT observations of high-J CO lines and [C II] observations of the super star cluster candidate H72.97-69.39 in the Large Magellanic Cloud (LMC), which is in its very early formation stage. We use our observations to determine if shocks are heating the gas or if photon-dominated regions (PDRs) are being heated by local far-UV rad…
On ancient solar-type stars - II
Fuhrmann, Klaus; Chini, Rolf
We report on the progress of our survey on ancient solar-type stars down to main-sequence effective temperatures Teff ≥ 5300 K and within 42 pc of the Sun. High signal-to-noise, high-resolution spectroscopy is presented for a second major subset of the Population II (τ ≥ 12 Gyr) and the intermediate-disc stars (τ ≃ 10 Gyr) within that v…
Detection of volatiles undergoing sublimation from 67P/Churyumov-Gerasimenko coma particles using ROSINA/COPS. II. The nude gauge
Altwegg, K.; Balsiger, H.; Rubin, M. +5 more
Context. In an earlier study, we reported that the ram gauge of the COmet Pressure Sensor (COPS), one of the three instruments of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA), could be used to obtain information about the sublimating content of icy particles, made up of volatiles and conceivably refractories coming from c…
Far-ultraviolet Variables in M31: Concentration in Spiral Arms and Association with Young Stars
Buick, Megan; Postma, Joseph E.; Leahy, Denis A.
The Andromeda galaxy (M31) is an object of ongoing study with the Ultraviolet Imaging Telescope (UVIT) on AstroSat. Field 2, which is 6.4 kpc in diameter at the distance of M31, includes a substantial part of the NE spiral arms of the galaxy. We have obtained a second observation of Field 2 with the far-ultraviolet (FUV) F148W (148 nm) filter, sep…
The Abundance of Lead in Four Metal-poor Stars
Peterson, Ruth C.
Cowan et al. review how roughly half the elements heavier than iron found in the Sun are produced by rapid neutron capture and half by slow neutron capture, the r- and s-processes. In the Sun, their relative contribution to individual elemental abundances is well understood, except for the lightest and heaviest elements beyond iron. Their contribu…
Detecting and Characterising Small-Scale Brightenings in Solar Imaging Data
Morgan, Huw; Humphries, Llŷr Dafydd; Kuridze, David
Observations of small-scale brightenings in the low solar atmosphere can provide valuable constraints on possible heating and heat transport mechanisms. We present a method for the detection and analysis of brightenings, and demonstrate its application to time-series imagery of the Interface Region Imaging Spectrograph (IRIS) in the extreme ultrav…
Comparison of the Orbital Properties of the Milky Way Globular Clusters from the Data of the Gaia DR2 and EDR3 Catalogs
Bobylev, V. V.; Bajkova, A. T.
We provide new values of the orbital parameters of 152 globular clusters, which are calculated using the new mean proper motions obtained from the Gaia EDR3 catalog data. The orbits were integrated 5 Gyr back in an axisymmetric three-component potential with a spherical bulge, disk component, and spherical dark halo in the Navarro-Frenk-White form…
Limits on the contribution of early endogenous radiolysis to oxidation in carbonaceous chondrites' parent bodies
Mousis, Olivier; Miller, Kelly E.; Bouquet, Alexis +1 more
Context. Carbonaceous chondrites have undergone alteration in their parent bodies and display oxidized secondary phases, including sulfates in CI and CM chondrites. The cause of the formation of these sulfates is yet to be determined.
Aims: This study investigates the potential of endogenous radiolysis of water (i.e., radiolysis caused by rad…
3D Parameter Maps of Red Clump Stars in the Milky Way: Absolute Magnitudes and Intrinsic Colors
Wang, Shu; Chen, Xiaodian
Red clump stars (RCs) are useful tracers of distances, extinction, chemical abundances, and Galactic structures and kinematics. Accurate estimation of RC parameters-absolute magnitude and intrinsic color-is the basis for obtaining high-precision RC distances. By combining astrometric data from Gaia; spectroscopic data from APOGEE and LAMOST; and m…
Touching the Stars: Using High-resolution 3D Printing to Visualize Stellar Nurseries
Forbes, John C.; Imara, Nia; Weaver, James C.
Owing to their intricate variable density architecture, and as a principal site of star formation, molecular clouds represent one of the most functionally significant, yet least understood features of our universe. To unravel the intrinsic structural complexity of molecular clouds, here we leverage the power of high-resolution bitmap-based three-d…