Search Publications
Crepuscular Rays from the Highly Inclined Active Galactic Nucleus in IC 5063
Ho, Luis C.; Elvis, Martin; Barth, Aaron J. +10 more
On Earth near sunset, the Sun may cast "crepuscular rays" such that clouds near the horizon obscure the origin of light scattered in bright rays. In principle, active galactic nuclei (AGN) should be able to produce similar effects. Using new Hubble Space Telescope (HST) near-infrared and optical observations, we show that the active galaxy IC 5063…
Existence of the Metal-rich Stellar Halo and High-velocity Thick Disk in the Galaxy
Shi, Jianrong; Ma, Jun; Du, Cuihua +3 more
Based on the second Gaia data release (DR2), combined with the LAMOST and APOGEE spectroscopic surveys, we study the kinematics and metallicity distribution of the high-velocity stars that have a relative speed of at least 220 $\mathrm{km}\ {{\rm{s}}}^{-1}$ with respect to the local standard of rest in the Galaxy. The rotational velocity distribut…
Spectral Structures of Type II Solar Radio Bursts and Solar Energetic Particles
Yashiro, Seiji; Nitta, Nariaki V.; Iwai, Kazumasa +1 more
We investigated the relationship between the spectral structures of type II solar radio bursts in the hectometric and kilometric wavelength ranges and solar energetic particles (SEPs). To examine the statistical relationship between type II bursts and SEPs, we selected 26 coronal mass ejection (CME) events with similar characteristics (e.g., initi…
Testing the Fidelity of Simulations of Black Hole-Galaxy Coevolution at z ∼ 1.5 with Observations
Treu, Tommaso; Bhowmick, Aklant K.; Menci, N. +3 more
We examine the scaling relations between the mass of a supermassive black hole (SMBH) and its host galaxy properties at 1.2 < z <1.7 using both observational data and simulations. Recent measurements of 32 X-ray-selected, broad-line active galactic nuclei (AGNs) are compared with two independent state-of-the-art efforts, including the hydrod…
Mapping Circumstellar Magnetic Fields of Late-type Evolved Stars with the Goldreich-Kylafis Effect: CARMA Observations at λ1.3 mm of R Crt and R Leo
Lai, Shih-Ping; Agudo, Iván; Vlemmings, Wouter H. T. +3 more
Mapping magnetic fields is the key to resolving the unclear physical picture of circumstellar magnetic fields in late-type evolved stars. Observations of linearly polarized emission from thermal molecular line transitions due to the Goldreich-Kylafis (G-K) effect provide valuable insights into the magnetic field geometry in these sources that are …
Velocity Response of the Observed Explosive Events in the Lower Solar Atmosphere. I. Formation of the Flowing Cool-loop System
Tiwari, Sanjiv K.; Srivastava, A. K.; Konkol, P. +6 more
We observe plasma flows in cool loops using the Slit-Jaw Imager on board the Interface Region Imaging Spectrometer (IRIS). Huang et al. observed unusually broadened Si IV 1403 Šline profiles at the footpoints of such loops that were attributed to signatures of explosive events (EEs). We have chosen one such unidirectional flowing cool-loop system …
Gemini Multi-Object Spectrograph Integral Field Unit Spectroscopy of the Double-peaked Broad Emission Line of a Red Active Galactic Nucleus
Ho, Luis C.; Im, Myungshin; Kim, Minjin +1 more
Galaxy mergers are expected to produce multiple supermassive black holes (SMBHs) in close-separation, but the detection of such SMBHs has been difficult. 2MASS J165939.7 + 183436 is a red active galactic nucleus (AGN) that is a prospective merging SMBH candidate owing to its merging features in Hubble Space Telescope imaging and double-peaked broa…
The Advanced Spectral Library (ASTRAL): Abundance Analysis of the Chemically Peculiar Star HR 465
Carpenter, Kenneth G.; Nielsen, Krister E.; Wahlgren, Glenn M. +1 more
This paper presents the results of the spectrum analysis of the B-type magnetic chemically peculiar star HR 465. HR 465 shows unusual abundance patterns that vary with a period of 21.5 yr. Our observations are recorded at φ = 0.45, 0.68, and 0.85 of the spectroscopic period, where φ = 0 represents the phase of maximum flux in the photometric y-ban…
A Mechanistic Study on the Formation of Acetic Acid (CH3COOH) in Polar Interstellar Analog Ices Exploiting Photoionization Reflectron Time-of-flight Mass Spectrometry
Kleimeier, N. Fabian; Eckhardt, André K.; Kaiser, Ralf I.
Acetic acid (CH3COOH) is considered a key molecule in the formation of the simplest amino acid, glycine, and consequently peptides. It is ubiquitous in the interstellar medium and has been detected toward hot cores, in the coma of comets, and on the surface of the comet 67P/Churyumov-Gerasimenko by the Rosetta mission. Here we present t…
Multiepoch VLBI of L Dwarf Binary 2MASS J0746+2000AB: Precise Mass Measurements and Confirmation of Radio Emission from Both Components
Hallinan, Gregg; Zhang, Qicheng; Golden, Aaron +2 more
Surveys have shown that up to 1/10th of all ultracool dwarfs (UCDs) are appreciable radio emitters, with their emission attributed to a combination of gyrosynchrotron radiation and the electron cyclotron maser instability. 2M J0746+2000AB is a close stellar binary comprised of an L0 and L1.5 dwarf that was previously identified as a source of 5 GH…