Search Publications
Compact molecular gas emission in local LIRGs among low- and high-z galaxies
Rigopoulou, D.; Colina, L.; Valentino, F. +12 more
We present new CO(2-1) observations of a representative sample of 24 local (z < 0.02) luminous infrared galaxies (LIRGs) at high spatial resolution (< 100 pc) from the Atacama Large Millimeter/submillimeter Array (ALMA). Our LIRGs lie above the main sequence (MS), with typical stellar masses in the range 1010-1011 M
Dynamical Masses of the Primary Be Star and Secondary sdB Star in the Single-lined Binary κ Dra (B6 IIIe)
Gies, Douglas R.; Wang, Luqian; Klement, Robert +16 more
Because many classical Be stars may owe their nature to mass and angular-momentum transfer in a close binary, the present masses, temperatures, and radii of their components are of high interest for comparison to stellar evolution models. Object κ Dra is a 61.5 day single-lined binary with a B6 IIIe primary. With the CHARA Array instruments MIRC/M…
Stars That Approach within One Parsec of the Sun: New and More Accurate Encounters Identified in Gaia Data Release 3
Bailer-Jones, C. A. L.
Close encounters of stars to the Sun could affect life on Earth through gravitational perturbations of comets in the Oort cloud or exposure to ionizing radiation. By integrating orbits through the Galactic potential, I identify which of 33 million stars in Gaia DR3 with complete phase space information come close to the Sun. 61 stars formally appr…
NuSTAR Observations of AGNs with Low Observed X-Ray to [O III] Luminosity Ratios: Heavily Obscured AGNs or Turned-off AGNs?
Stern, Daniel; García, Javier A.; Malkan, Matthew A. +2 more
Type 2 active galactic nuclei (AGNs) show signatures of accretion onto a supermassive black hole through strong, high-ionization, narrow emission lines extended on scales of hundreds to thousands of parsecs, but they lack the broad emission lines from close in to the black hole that characterize type 1 AGNs. The lack of broad emission could indica…
The Quasar Feedback Survey: revealing the interplay of jets, winds, and emission-line gas in type 2 quasars with radio polarization
Mainieri, V.; Harrison, C. M.; Jarvis, M. E. +4 more
We present results from a combined radio polarization and emission-line study of five type 2 quasars at z < 0.2 with the Karl G. Jansky Very Large Array (VLA) B-array at 5 GHz and Hubble Space Telescope (HST) [O III] observations. These five sources are known to exhibit close association between radio structures and ionized gas morphology and k…
Accretion Disk Outflow during the X-Ray Flare of the Super-Eddington Active Nucleus of I Zwicky 1
Ho, Luis C.; Ricci, Claudio; Li, Ruancun +1 more
We present a detailed X-ray spectral analysis of the narrow-line Seyfert 1 galaxy I Zwicky 1, for which a sequence of X-ray flares were detected during a long, simultaneous observation acquired with XMM-Newton and NuSTAR. We determine the key parameters of the inner accretion disk and hot corona in the context of the disk reflection model, which s…
The Milky Way's middle-aged inner ring
Clarke, Jonathan P.; Wylie, Shola M.; Gerhard, Ortwin E.
Aims: We investigate the metallicity, age, and orbital anatomy of the inner Milky Way, specifically focussing on the outer bar region.
Methods: We integrated a sample of APOGEE DR16 inner Galaxy stars in a state of the art bar-bulge potential with a slow pattern speed and investigated the link between the resulting orbits and their [Fe/H…
The Effect of Current on Magnetic Null Topology during Turbulent Reconnection
Wang, Z.; Cao, J. B.; Liu, Y. Y. +5 more
Using data from the Cluster mission and the First-Order Taylor Expansion method, we investigate the spiral magnetic nulls nested in the diffusion region of turbulent reconnection in the magnetotail. We particularly focus on the relation between the magnetic null topologies and currents, which can be decomposed into a component perpendicular to spi…
ASAS J071404+7004.3 - a close, bright nova-like cataclysmic variable with gusty winds
Knigge, C.; Gänsicke, B. T.; Marsh, T. R. +11 more
Despite being bright (V ≃ 11.8) and nearby (d = 212 pc) ASAS J071404+7004.3 has only recently been identified as a nova-like cataclysmic variable. We present time-resolved optical spectroscopy obtained at the Isaac Newton and the Hiltner and McGraw-Hill Telescopes, together with Swift X-ray and ultraviolet observations. We combined these with TESS…
REXCOR: a model of the X-ray spectrum of active galactic nuclei that combines ionized reflection and a warm corona
Bianchi, S.; Petrucci, P. -O.; Matt, G. +6 more
The X-ray spectra of active galactic nuclei (AGNs) often exhibit an excess of emission above the primary power law at energies ≲2 keV. Two models for the origin of this 'soft excess' are ionized relativistic reflection from the inner accretion disc and Comptonization of thermal emission in a warm corona. Here, we introduce REXCOR, a new AGN X-ray …