Search Publications
Discovery of a Large Population of Nitrogen-enhanced Stars in the Magellanic Clouds
Beers, Timothy C.; Placco, Vinicius M.; Minniti, Dante +7 more
We report the APOGEE-2S+ discovery of a unique collection of nitrogen-enhanced mildly metal-poor giant stars, peaking at [Fe/H] ∼ -0.89 with no carbon enrichment, toward the Small and Large Magellanic Clouds (SMC and LMC), with abundances of light- (C, N), odd-Z (Al, K), and α-elements (O, Mg, Si) that are typically found in Galactic globular clus…
Fast Outflows in Hot Dust-obscured Galaxies Detected with Keck/NIRES
Tsai, Chao-Wei; Moon, Dae-Sik; Jun, Hyunsung D. +10 more
We present rest-frame optical spectroscopic observations of 24 Hot Dust-Obscured Galaxies (Hot DOGs) at redshifts 1.7-4.6 with KECK/NIRES. Our targets are selected, based on their extreme red colors, to be the highest-luminosity sources from the WISE infrared survey. In 20 sources with well-detected emission, we fit the key [O III], Hβ, Hα, [N II]…
Characterization of the K2-38 planetary system. Unraveling one of the densest planets known to date
Bouchy, F.; Rebolo, R.; Pallé, E. +90 more
Context. An accurate characterization of the known exoplanet population is key to understanding the origin and evolution of planetary systems. Determining true planetary masses through the radial velocity (RV) method is expected to experience a great improvement thanks to the availability of ultra-stable echelle spectrographs.
Aims: We took a…
Real-time Flare Prediction Based on Distinctions between Flaring and Non-flaring Active Region Spectra
Kleint, Lucia; Panos, Brandon
With machine learning entering into the awareness of the heliophysics community, solar flare prediction has become a topic of increased interest. Although machine-learning models have advanced with each successive publication, the input data has remained largely fixed on magnetic features. Despite this increased model complexity, results seem to i…
The R-process Alliance: The Peculiar Chemical Abundance Pattern of RAVE J183013.5-455510
Whitten, Devin D.; Beers, Timothy C.; Placco, Vinicius M. +14 more
We report on the spectroscopic analysis of RAVE J183013.5-455510, an extremely metal-poor star, highly enhanced in CNO, and with discernible contributions from the rapid neutron-capture process. There is no evidence of binarity for this object. At $[\mathrm{Fe}/{\rm{H}}]$ = -3.57, this star has one of the lowest metallicities currently observed, w…
A large, deep 3 deg2 survey of H α, [O III], and [O II] emitters from LAGER: constraining luminosity functions
Hu, W.; Infante, L.; Walker, A. R. +14 more
We present our measurements of the H α, [O III], and [O II] luminosity functions as part of the Lyman Alpha Galaxies at Epoch of Reionization (LAGER) survey using our samples of 1577 z = 0.47 H α-, 3933 z = 0.93 [O III]-, and 5367 z = 1.59 [O II]-selected emission line galaxies in a 3 deg2 single, CTIO/Blanco DECam pointing of the COSMO…
The Fifth Candidate for an Intermediate-mass Black Hole in the Galactic Center
Oka, Tomoharu; Tsujimoto, Shiho; Iwata, Yuhei +2 more
We report the results of high-resolution molecular line observations of the high-velocity compact cloud HCN-0.085-0.094 with the Atacama Large Millimeter/submillimeter Array. The HCN J = 4-3, HCO+ J = 4-3, and CS J = 7-6 line images reveal that HCN-0.085-0.094 consists mainly of three small clumps with extremely broad velocity widths. E…
Electron Pitch-Angle Distribution in Earth's Magnetotail: Pancake, Cigar, Isotropy, Butterfly, and Rolling-Pin
Wang, Z.; Xu, Y.; Chen, G. +4 more
Electron pitch-angle distributions, including isotropy, pancake, cigar, butterfly, and recently discovered rolling-pin distributions, are crucial to understanding electron dynamics in the magnetotail. However, occurrence rates of these distributions remain unclear. Here, for the first time, we reveal the occurrence rates of these distributions in …
Broadband Selection, Spectroscopic Identification, and Physical Properties of a Population of Extreme Emission-line Galaxies at 3 < z < 3.7
Harikane, Yuichi; Shibuya, Takatoshi; Suzuki, Tomoko L. +7 more
We present the selection, spectroscopic identification, and physical properties of extreme emission-line galaxies (EELGs) at 3 < z < 3.7, aiming at studying physical properties of an analog population of star-forming galaxies (SFGs) at the epoch of reionization. The sample is selected based on the excess in the observed Ks broadband flux rel…
Multiple mineral horizons in layered outcrops at Mawrth Vallis, Mars, signify changing geochemical environments on early Mars
Seelos, Frank P.; Murchie, Scott L.; Horgan, Briony +6 more
Refined calibrations of CRISM images are enabling identification of smaller deposits of unique aqueous materials on Mars that reveal changing environmental conditions at the region surrounding Mawrth Vallis. Through characterization of these clay-sulfate assemblages and their association with the layered, phyllosilicate units of this region, more …