Search Publications
Detailed analysis of the poorly studied northern open cluster NGC 1348 using multi-color photometry and GAIA EDR3 astrometry
Rangwal, Geeta; Zhu, Qingfeng; Jiang, Ing-Guey +5 more
The membership determination for open clusters in noisy environments of the Milky Way is still an open problem. In this paper, our main aim is to provide the membership probability of stars using proper motions and parallax values of stars using Gaia Third Data Release astrometry. Apart from the Gaia astrometry, we have also used other photometric…
Spatially Resolving the Star Formation Histories of Three Nearby Nuclear Star Clusters
Neumayer, Nadine; Kacharov, Nikolay; Seth, Anil C. +4 more
The formation of nuclear star clusters (NSCs) remains an open question. In this work, we use spatially-resolved HST/STIS spectroscopic observations of three nearby NSCs (hosted by NGC 5102, NGC 5206, and NGC 205) to constrain their formation histories by exploring radial variations of the stellar populations within each cluster. Utilizing full-spe…
The GRAVITY young stellar object survey. IV. The CO overtone emission in 51 Oph at sub-au scales
Genzel, R.; Sturm, E.; Labadie, L. +69 more
Context. 51 Oph is a Herbig Ae/Be star that exhibits strong near-infrared CO ro-vibrational emission at 2.3 µm, most likely originating in the innermost regions of a circumstellar disc.
Aims: We aim to obtain the physical and geometrical properties of the system by spatially resolving the circumstellar environment of the inner gaseous d…
Unlocking the Origins of Ultracool Dwarf Radio Emission
Hughes, A. G.; White, J. A.; Boley, A. C. +2 more
Empirical trends in stellar X-ray and radio luminosities suggest that low-mass ultracool dwarfs (UCDs) should not produce significant radio emission. Defying these expectations, strong nonthermal emission has been observed in a few UCDs in the 1-10 GHz range, with a variable component often attributed to global aurorae and a steady component attri…
Multiwavelength dissection of a massive heavily dust-obscured galaxy and its blue companion at z∼2
Daddi, E.; Béthermin, M.; Ciesla, L. +4 more
Aims: We study a system of two galaxies, Astarte and Adonis, at z ∼ 2. At this time, the Universe was undergoing the peak of its star formation activity. Astarte is a dusty star-forming galaxy at the massive end of the main sequence (MS), and Adonis is a less massive companion galaxy that is bright in the ultraviolet and has an optical spectr…
The Stars of the HETDEX Survey. I. Radial Velocities and Metal-poor Stars from Low-resolution Stellar Spectra
Finkelstein, Steven L.; Casey, Caitlin M.; Schneider, Donald P. +19 more
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) is an unbiased, massively multiplexed spectroscopic survey, designed to measure the expansion history of the universe through low-resolution (R ∼ 750) spectra of Lyα emitters. In its search for these galaxies, HETDEX will also observe a few times 105 stars. In this paper, we pre…
Evidence for Multiple Accretion Events in the Gaia-Sausage/Enceladus Structures
Koo, Jae-Rim; Beers, Timothy C.; Lee, Young Sun +1 more
We present evidence that multiple accretion events are required to explain the origin of the Gaia-Sausage and Enceladus (GSE) structures, based on an analysis of dynamical properties of main-sequence stars from the Sloan Digital Sky Survey Data Release 12 and Gaia Data Release 2. GSE members are selected to have eccentricity (e) > 0.7 and [Fe/H…
Comparing hypervelocity star populations from the Large Magellanic Cloud and the Milky Way
Rossi, E. M.; Marchetti, T.; Evans, F. A. +2 more
We predict and compare the distributions and properties of hypervelocity stars (HVSs) ejected from the centres of the Milky Way (MW) and the Large Magellanic Cloud (LMC). In our model, HVSs are ejected at a constant rate - equal in both galaxies - via the Hills mechanism and are propagated in a combined potential, where the LMC orbits the MW on it…
A super-Earth on a close-in orbit around the M1V star GJ 740. A HADES and CARMENES collaboration
Rebolo, R.; Amado, P. J.; Caballero, J. A. +23 more
Context. M-dwarfs have proven to be ideal targets for planetary radial velocity (RV) searches due to their higher planet-star mass contrast, which favors the detection of low-mass planets. The abundance of super-Earth and Earth-like planets detected around this type of star motivates further such research on hosts without reported planetary compan…
The MOSDEF-LRIS Survey: Probing the ISM/CGM Structure of Star-forming Galaxies at z 2 Using Rest-UV Spectroscopy
Siana, Brian; Shapley, Alice E.; Reddy, Naveen A. +6 more
The complex structure of gas, metals, and dust in the interstellar and circumgalactic medium (ISM and CGM, respectively) in star-forming galaxies can be probed by Lyα emission and absorption, low-ionization interstellar (LIS) metal absorption, and dust reddening E(B - V). We present a statistical analysis of the mutual correlations among Lyα equiv…