Search Publications
New Constraints on Early-type Galaxy Assembly from Spectroscopic Metallicities of Globular Clusters in M87
Romanowsky, Aaron J.; Strader, Jay; Brodie, Jean +1 more
The observed characteristics of globular cluster (GC) systems, such as metallicity distributions, are commonly used to place constraints on galaxy formation models. However, obtaining reliable metallicity values is particularly difficult because of our limited means to obtain high quality spectroscopy of extragalactic GCs. Often, “color-metallicit…
The Cold Circumgalactic Environment of MAMMOTH-I: Dynamically Cold Gas in the Core of an Enormous Lyα Nebula
Prochaska, J. Xavier; Lehnert, Matthew D.; Cai, Zheng +2 more
The MAMMOTH-I Nebula at redshift 2.3 is one of the largest known Lyα nebulae in the universe, spanning ∼440 kpc. Enormous Lyα nebulae like MAMMOTH-I typically trace the densest and most active regions of galaxy formation. Using sensitive low-surface-brightness observations of CO(1-0) with the Very Large Array, we trace the cold molecular gas in th…
Infrared Spectroscopy of Symbiotic Stars. XII. The Neutron Star SyXB System 4U 1700+24 = V934 Herculis
Mikołajewska, Joanna; Fekel, Francis C.; Hinkle, Kenneth H. +3 more
The X-ray symbiotic (SyXB) V934 Her = 4U 1700+24 is an M giant-neutron star (NS) binary system. Employing optical and infrared radial velocities spanning 29 yr combined with the extensive velocities in the literature, we compute the spectroscopic orbit of the M giant in that system. We determine an orbital period of 4391 days, or 12.0 yr, the long…
Molecular Cloud Distances Based on the MWISP CO Survey and Gaia DR2
Xu, Ye; Su, Yang; Yan, Qing-Zeng +2 more
We present a new method of calculating distances of molecular clouds in the Galactic plane, using CO observations and the Gaia DR2 parallax and G-band extinction (A G ) measurements. Due to the complexity of dust environments in the Galactic plane, A G contains irregular variations, which are difficult to model. To overcom…
Probing ISM Structure in Trumpler 14 and Carina I Using the Stratospheric Terahertz Observatory 2
van der Tak, Floris F. S.; Tolls, Volker; Horiuchi, Shinji +26 more
We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2. The Trumpler 14/Carina I region is in the western part of the Carina Nebula Complex (CNC), which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 µm transition of…
Exploring the dimming event of RW Aurigae A through multi-epoch VLT/X-shooter spectroscopy
Ray, T. P.; Coffey, D.; Natta, A. +6 more
Context. RW Aur A is a classical T Tauri star that has suddenly undergone three major dimming events since 2010. The reason for these dimming events is still not clear.
Aims: We aim to understand the dimming properties, examine accretion variability, and derive the physical properties of the inner disc traced by the CO ro-vibrational emission…
K2-140b and K2-180b - Characterization of a hot Jupiter and a mini-Neptune from the K2 mission
Kuzuhara, M.; Alonso, R.; Erikson, A. +40 more
We report the independent discovery and characterization of two K2 planets: K2-180b, a mini-Neptune-sized planet in an 8.9-d orbit transiting a V = 12.6 mag, metal-poor ([Fe/H] = -0.65 ± 0.10) K2V star in K2 campaign 5; K2-140b, a transiting hot Jupiter in a 6.6-d orbit around a V = 12.6 mag G6V ([Fe/H] = + 0.10 ± 0.10) star in K2 campaign 10. Our…
Jupiter's auroral-related stratospheric heating and chemistry III: Abundances of C2H4, CH3C2H, C4H2 and C6H6 from Voyager-IRIS and Cassini-CIRS
Fletcher, L. N.; Irwin, P. G. J.; Orton, G. S. +4 more
We present an analysis of Voyager-1-IRIS and Cassini-CIRS spectra of Jupiter's high latitudes acquired during the spacecrafts' respective flybys in November 1979 and January 2001. We performed a forward-model analysis in order to derive the abundances of ethylene (C2H4), methylacetylene (CH3C2H), diacety…
High frequencies in TESS A-F main-sequence stars
Balona, L. A.; Cunha, M. S.; Holdsworth, D. L.
The driving mechanism for high-frequency oscillations in some chemically peculiar Ap stars, the rapidly oscillating Ap stars (roAp stars), is not understood. The Transiting Exoplanet Survey Satellite mission (TESS) data provide an ideal opportunity to extend the number of roAp stars that might provide further clues to address this problem. From an…
Spectroscopic study of two new super Li-rich red clump K giants
Reddy, Bacham E.; Kumar, Yerra Bharat; Singh, Raghubar
In this paper, we report the discovery of two new super Li-rich K giants: HD 24960 and TYC 1751-1713-1. Based on high-resolution (R ≈ 60 000) spectroscopy, we have derived Li abundance of A(Li) ≈ 4.0 dex for both stars. Other elemental abundances are normal of typical K giants. Low ratios of [C/N] ≤ -0.25 and 12C/13C ≤ 10 sug…