Search Publications
On the Oosterhoff dichotomy in the Galactic bulge - II. Kinematical distribution
Smolec, R.; Grebel, E. K.; Catelan, M. +3 more
We present a kinematical study of RR Lyrae stars associated with two Oosterhoff groups in the Galactic bulge. We used data published in the first paper of the series, plus proper motions from the Gaia Data Release 2, and radial velocities from the literature. A 6D kinematical and spatial solution was obtained for 429 RR Lyrae stars. We use a model…
First MMS Observation of Energetic Particles Trapped in High-Latitude Magnetic Field Depressions
Fuselier, Stephen A.; Nykyri, Katariina; Ma, Xuanye +2 more
We present a case study of the Magnetospheric Multiscale (MMS) observations of the Southern Hemispheric dayside magnetospheric boundaries under southward interplanetary magnetic field direction with strong By component. During this event MMS encountered several magnetic field depressions characterized by enhanced plasma beta and high fl…
Compton-thick AGN in the NuSTAR Era. IV. A Deep NuSTAR and XMM-Newton View of the Candidate Compton-thick AGN in ESO 116-G018
Ajello, M.; Marchesi, S.; Zhao, X.
We present a 2-78 keV spectral analysis of the deep NuSTAR and XMM-Newton observation of a nearby Seyfert 2 galaxy, ESO 116-G018, which is selected as a candidate Compton-thick (CT) active galactic nucleus (AGN) based on a previous Chandra-Swift-BAT study. Through our analysis, the source is, for the first time, confirmed to be a CT AGN at a >3…
The Blueshift of the C IV Broad Emission Line in QSOs
Bian, Wei-Hao; Ge, Xue; Zhao, Bi-Xuan +1 more
For the sample from Ge et al. of 87 low-z Palomar-Green quasi-stellar objects (QSOs) and 130 high-z QSOs (0 < z < 5) with {{H}}β -based single-epoch supermassive black hole masses, we perform a uniform decomposition of the C IV λ1549 broad-line profile. Based on the rest frame defined by the [O III] λ5007 narrow emission line, a medium-stron…
Space astrometry of the very massive ∼150 M⊙ candidate runaway star VFTS682
Lennon, D. J.; Renzo, M.; Platais, I. +12 more
How very massive stars form is still an open question in astrophysics. VFTS682 is among the most massive stars known, with an inferred initial mass of ≳150 M_⊙. It is located in 30 Doradus at a projected distance of 29 pc from the central cluster R136. Its apparent isolation led to two hypotheses: either it formed in relative isolation or it was e…
Spectroscopic Mass and Host-star Metallicity Measurements for Newly Discovered Microlensing Planet OGLE-2018-BLG-0740Lb
Kollmeier, Juna A.; Morrell, Nidia; Han, Cheongho +67 more
We report the discovery of the microlensing planet OGLE-2018-BLG-0740Lb. The planet is detected with a very strong signal of Δχ 2 ∼ 4630, but the interpretation of the signal suffers from two types of degeneracies. One type is caused by the previously known close/wide degeneracy, and the other is caused by an ambiguity between two solut…
Dwarfs or Giants? Stellar Metallicities and Distances from ugrizG Multiband Photometry
Lewis, Geraint F.; Jensen, Jaclyn; Navarro, Julio F. +19 more
We present a new fully data-driven algorithm that uses photometric data from the Canada-France Imaging Survey (CFIS; u), Pan-STARRS 1 (PS1; griz), and Gaia (G) to discriminate between dwarf and giant stars and to estimate their distances and metallicities. The algorithm is trained and tested using the Sloan Digital Sky Survey (SDSS)/SEGUE spectros…
Reconnection Front Associated with Asymmetric Magnetic Reconnection: Particle-in-cell Simulations
Zhou, Meng; Deng, Xiaohua; Zhong, Zhihong +2 more
Reconnection front (RF) has frequently been observed in the magnetotail and is well known as the dipolarization front in the near-Earth tail. Whether the RF exists in reconnection with distinct plasma/field properties across the reconnecting current sheet (i.e., asymmetric reconnection) is unknown yet. In this Letter, we use 2.5D particle-in-cell …
Tycho's Supernova: The View from Gaia
Bedin, Luigi R.; Ruiz-Lapuente, Pilar; Figueras, Francesca +6 more
SN 1572 (Tycho Brahe’s supernova) clearly belongs to the Ia (thermonuclear) type. It was produced by the explosion of a white dwarf (WD) in a binary system. Its remnant has been the first of this type to be explored in search of a possible surviving companion, the mass donor that brought the WD to the point of explosion. A high peculiar motion wit…
Synthetic 26Al emission from galactic-scale superbubble simulations
Diehl, R.; Rodgers-Lee, D.; Krause, M. G. H. +1 more
Emission from the radioactive trace element 26Al has been observed throughout the Milky Way with the COMPTEL and INTEGRAL satellites. In particular, the Doppler shifts measured with INTEGRAL connect 26Al with superbubbles, which may guide 26Al flows off spiral arms in the direction of Galactic rotation. In order to…