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Study of a Red Clump Giant, KIC 11087027, with High Rotation and Strong Infrared Excess—Evidence of Tidal Interaction for High Lithium Abundance
Zhao, Gang; Reddy, Bacham E.; Pandey, Jeewan C. +2 more
This Letter presents results from Kepler photometric light curves and a high-resolution spectroscopic study of a super-Li-rich giant KIC11087027. Using the light-curve analysis, we measured the star's rotational period P rot = 30.4 ± 0.1 days, which translates to rotational velocity V rot = 19.5 ± 1.7 km s‑1. The s…
Evidence of Third Dredge-up in Post-AGB Stars in Galactic Globular Clusters
Dixon, William V.
To better understand the mixing and mass loss experienced by low-mass stars as they ascend the asymptotic giant branch (AGB), I have gathered from the literature the abundances of CNO and s-process elements in post-AGB stars in Galactic globular clusters. These species are mixed to the surface during third dredge-up (3DU) events, so their abundanc…
Exploring the Diversity of Faint Satellites in the M81 Group
Bell, Eric F.; Monachesi, Antonela; Bailin, Jeremy +9 more
In the last decade, we have been able to probe further down the galaxy luminosity function than ever before and expand into the regime of ultra-faint dwarfs (UFDs), which are some of the best probes we have of small-scale cosmology and galaxy formation. Digital sky surveys have enabled the discovery and study of these incredibly low-mass, highly d…
On the Origin of Infrared Bands Attributed to Tryptophan in Spitzer Observations of IC 348
McGuire, Brett A.; Jørgensen, Jes K.; Schroetter, Ilane +12 more
Infrared emission features toward interstellar gas of the IC 348 star cluster in Perseus have been recently proposed to originate from the amino acid tryptophan. The assignment was based on laboratory infrared spectra of tryptophan pressed into pellets, a method which is known to cause large frequency shifts compared to the gas phase. We assess th…
Differential Rotation of CoRoT Stars and a Kepler Binary Star from Starspot Transit Mapping
Valio, Adriana; Araújo, Alexandre; Menezes, Fabian
While direct magnetic field measurements are rare for slowly rotating stars, spots observed during planetary transits provide a potential indicator of magnetic activity on stellar surfaces. Moreover, the rotation of the stellar surface can be probed by monitoring the spots' position with time in subsequent transits. This study investigates the dyn…
Metallicity Mapping of the Ionized Diffuse Gas at the Milky Way Disk–Halo Interface
Prochaska, J. Xavier; Strader, Jay; Putman, Mary E. +5 more
Metals in the diffuse, ionized gas at the boundary between the Milky Way's interstellar medium (ISM) and circumgalactic medium, known as the disk–halo interface (DHI), are valuable tracers of the feedback processes that drive the Galactic fountain. However, metallicity measurements in this region are challenging due to obscuration by the Milky Way…
Subaru/CHARIS High-resolution Mode Spectroscopy of the Brown Dwarf Companion HD 33632 Ab
Jensen-Clem, Rebecca; Lewis, Briley L.; Fitzgerald, Michael P. +6 more
Brown dwarfs (BDs) are model degenerate in age and mass. High-contrast imaging and spectroscopy of BD companions to host stars where the mass and age can be independently constrained by dynamics and stellar age indicators, respectively, provide valuable tests of BD evolution models. In this paper, we present a new epoch of Subaru/CHARIS H- and K-b…
On the Kinematic Nature of Apparent Disks at High Redshifts: Local Counterparts are Not Dominated by Ordered Rotation but by Tangentially Anisotropic Random Motion
Cappellari, Michele; Gao, Hua; Peng, Yingjie +2 more
It is not straightforward to physically interpret the apparent morphology of galaxies. Recent observations by the James Webb Space Telescope (JWST) revealed a dominant galaxy population at high redshifts (z > 2) that were visually classified as disks for their flattened shapes and/or exponential light profiles. The extensively accepted interpre…
SAUNAS. I. Searching for Low Surface Brightness X-Ray Emission with Chandra/ACIS
Koekemoer, Anton M.; Laine, Seppo; Lopez-Rodriguez, Enrique +8 more
We present Selective Amplification of Ultra Noisy Astronomical Signal (SAUNAS), a pipeline designed for detecting diffuse X-ray emission in the data obtained with the Advanced CCD Imaging Spectrometer (ACIS) of the Chandra X-ray Observatory. SAUNAS queries the available observations in the Chandra archive and performs photometric calibration, poin…
Supernova Ejecta with Crystalline Silicate Dust in the Supernova Remnant MSH 15–52
Onaka, Takashi; Koo, Bon-Chul; Kim, Hyun-Jeong
IRAS 15099-5856 in the young supernova remnant (SNR) MSH 15‑52 is the first and only SNR-associated object with crystalline silicate dust detected so far, although its nature and the origin of the crystalline silicate are still unclear. In this paper, we present high-resolution mid-infrared (MIR) imaging observations of the bright central compact …