Search Publications
The MBHBM⋆ Project. I. Measurement of the Central Black Hole Mass in Spiral Galaxy NGC 3504 Using Molecular Gas Kinematics
Imanishi, Masatoshi; Neumayer, Nadine; Greene, Jenny E. +17 more
We present a dynamical mass measurement of the supermassive black hole (SMBH) in the nearby double-barred spiral galaxy NGC 3504 as part of the Measuring Black Holes in below Milky Way (M⋆) Mass Galaxies Project. Our analysis is based on Atacama Large Millimeter/submillimeter Array cycle 5 observations of the 12CO(2-1) emissi…
Fine Structure of a Solar Type II Radio Burst Observed by LOFAR
Zucca, Pietro; Vocks, Christian; Mann, Gottfried +6 more
Shock waves in the solar corona are closely associated with coronal mass ejections and flares. The longest-known and frequently studied signatures of coronal shock waves are metric type II radio bursts, which provide information on the shock driver and ambient plasma conditions. We report on outstanding high frequency/time resolution LOw Frequency…
Noninteracting Black Hole Binaries with Gaia and LAMOST
Liu, Jifeng; Wiktorowicz, Grzegorz; Lu, Youjun +4 more
Until recently, black holes (BHs) could be discovered only through accretion from other stars in X-ray binaries, or in merging double compact objects. Improvements in astrometric and spectroscopic measurements have made it possible to detect BHs also in noninteracting BH binaries (nBHBs) through a precise analysis of the companion's motion. In thi…
Space Telescope and Optical Reverberation Mapping Project. XII. Broad-line Region Modeling of NGC 5548
Im, M.; Fox, O. D.; Malkan, M. A. +155 more
We present geometric and dynamical modeling of the broad line region (BLR) for the multi-wavelength reverberation mapping campaign focused on NGC 5548 in 2014. The data set includes photometric and spectroscopic monitoring in the optical and ultraviolet, covering the Hβ, C IV, and Lyα broad emission lines. We find an extended disk-like Hβ BLR with…
COol Companions ON Ultrawide orbiTS (COCONUTS). I. A High-gravity T4 Benchmark around an Old White Dwarf and a Re-examination of the Surface-gravity Dependence of the L/T Transition
Magnier, Eugene A.; Hermes, J. J.; Marley, Mark S. +7 more
We present the first discovery from the COol Companions ON Ultrawide orbiTS (COCONUTS) program, a large-scale survey for wide-orbit planetary and substellar companions. We have discovered a comoving system COCONUTS-1, composed of a hydrogen-dominated white dwarf (PSO J058.9855+45.4184; d = 31.5 pc) and a T4 companion (PSO J058.9869+45.4296) at a 4…
Open Cluster Chemical Homogeneity throughout the Milky Way
Beaton, Rachael L.; Hawkins, K.; Cunha, K. +10 more
The chemical homogeneity of surviving stellar clusters contains important clues about interstellar medium (ISM) mixing efficiency, star formation, and the enrichment history of the Galaxy. Existing measurements in a handful of open clusters suggest homogeneity in several elements at the 0.03 dex level. Here we present (i) a new cluster member cata…
Models of the Mass-ejection Histories of Pre-planetary Nebulae. IV. Magnetized Winds and the Origins of Jets, Bullets, and FLIERs
Frank, Adam; Balick, Bruce; Liu, Baowei
This paper explores the influences and consequences of toroidal magnetic fields in shaping the visible lobes of pre-planetary nebulae (prePNe). To probe these influences we start with the steady, diverging, and field-free wind model of our previous papers and add weak to moderate toroidal fields to the winds in order to generate arrays of outcomes…
Self-consistent Analysis of Stellar Clusters: An Application to HST Data of the Halo Globular Cluster NGC 6752
Nardiello, D.; Barbuy, B.; Pérez-Villegas, A. +3 more
The Bayesian isochrone fitting using the Markov chain Monte Carlo algorithm is applied, to derive the probability distribution of the parameters age, metallicity, reddening, and absolute distance modulus. We introduce the SIRIUS code by means of simulated color-magnitude diagrams (CMDs), including the analysis of multiple stellar populations (MPs)…
Stellar Metallicities from SkyMapper Photometry I: A Study of the Tucana II Ultra-faint Dwarf Galaxy
Jerjen, Helmut; Frebel, Anna; Chiti, Anirudh +2 more
We present a study of the ultra-faint Milky Way dwarf satellite galaxy Tucana II using deep photometry from the 1.3 m SkyMapper telescope at Siding Spring Observatory, Australia. The SkyMapper filter set contains a metallicity-sensitive intermediate-band V filter covering the prominent Ca II K feature at 3933.7 Å. When combined with photometry fro…
Orbital Evidences for Dark-matter-free Milky Way Dwarf Spheroidal Galaxies
Hammer, Francois; Babusiaux, Carine; Bonifacio, Piercarlo +4 more
The nature of Milky Way dwarf spheroidals (MW dSphs) has been questioned, in particular whether they are dominated by dark matter (DM). Here we investigate an alternative scenario, for which tidal shocks are exerted by the MW to DM-free dSphs after a first infall of their gas-rich progenitors, and for which theoretical calculations have been verif…