Search Publications

Solar Origin of Bare Ion Anomalies in the Solar Wind and Interplanetary Coronal Mass Ejections
DOI: 10.3847/1538-4357/ac1676 Bibcode: 2021ApJ...921...93R

Reeves, Katharine K.; Raymond, John C.; Stevens, Michael L. +3 more

Previous studies of the solar wind and interplanetary coronal mass ejections (ICMEs) have shown periods throughout solar cycle 23 when heliospheric measurements of ion composition appear anomalous. In these cases, C6+ and other bare ion densities, i.e., fully stripped ions, are unusually low, leading it to be classified as the Outlier s…

2021 The Astrophysical Journal
Ulysses 14
ARMADA. I. Triple Companions Detected in B-type Binaries α Del and ν Gem
DOI: 10.3847/1538-3881/abcf4e Bibcode: 2021AJ....161...40G

Gies, Douglas R.; Klement, Robert; Monnier, John D. +19 more

Ground-based optical long-baseline interferometry has the power to measure the orbits of close binary systems at ∼10 µas precision. This precision makes it possible to detect "wobbles" in the binary motion due to the gravitational pull from additional short-period companions. We started the ARrangement for Micro-Arcsecond Differential Astrom…

2021 The Astronomical Journal
Gaia 14
Probing within the Bondi radius of the ultramassive black hole in NGC 1600
DOI: 10.1093/mnras/stab444 Bibcode: 2021MNRAS.502.5487R

Walker, S. A.; Runge, J.

We present deep (250 ks) Chandra observations of the nearby galaxy group NGC 1600, which has at its centre an ultramassive black hole (17 ± 1.5 billion M). The exceptionally large mass of the black hole coupled with its low redshift makes it one of only a handful of black holes for which spatially resolved temperature and density profi…

2021 Monthly Notices of the Royal Astronomical Society
eHST 14
Modeling the Observed Distortion of Multiple (Ghost) CME Fronts in STEREO Heliospheric Imagers
DOI: 10.3847/2041-8213/ac1203 Bibcode: 2021ApJ...917L..16C

Wang, Yuming; Shen, Chenglong; Lockwood, Mike +10 more

In this work we have, for the first time, applied the interpretation of multiple "ghost-fronts" to two synthetic coronal mass ejections (CMEs) propagating within a structured solar wind using the Heliospheric Upwind eXtrapolation time (HUXt) solar wind model. The two CMEs occurred on 2012 June 13-14 showing multiple fronts in images from Solar Ter…

2021 The Astrophysical Journal
SOHO 14
The Kiloparsec-scale Fe Ka Emission in the Compton-thin Seyfert 2 Galaxy NGC 4388 Resolved by Chandra
DOI: 10.3847/1538-4357/abcec3 Bibcode: 2021ApJ...908..156Y

Fabbiano, Giuseppina; Shu, Xinwen; Wang, Junfeng +4 more

We present imaging and spectral analysis of the combined ∼48 ks Chandra observations of Seyfert 2 galaxy NGC 4388. Compared with previous studies, three prominent extended X-ray structures around the nucleus on a kiloparsec-scale are well imaged, allowing an in-depth spatially resolved study. Both the extended hard continuum (4-6 keV) and the Fe K…

2021 The Astrophysical Journal
eHST 14
Numerical Modeling of Latitudinal Gradients for Galactic Cosmic-Ray Protons during Solar Minima: Comparing with Ulysses Observations
DOI: 10.3847/1538-4365/ac0a78 Bibcode: 2021ApJS..256...18S

Qin, Gang; Shen, Zhenning; Zuo, Pingbing +2 more

The latitudinal gradients of galactic cosmic-ray (GCR) protons measured by Ulysses during two successive minima provide a unique opportunity to study the modulation effects in polar regions of the heliosphere. In this work, a GCR modulation model based on numerically solving the Parker transport equation is used to study the latitudinal distributi…

2021 The Astrophysical Journal Supplement Series
Ulysses 14
The luminosity functions and redshift evolution of satellites of low-mass galaxies in the COSMOS survey
DOI: 10.1093/mnras/stab069 Bibcode: 2021MNRAS.502.1205R

Roberts, Daniella M.; Nierenberg, Anna M.; Peter, Annika H. G.

The satellite populations of the Milky Way, and Milky Way mass galaxies in the local Universe, have been extensively studied to constrain dark matter and galaxy evolution physics. Recently, there has been a shift to studying satellites of hosts with stellar masses between that of the Large Magellanic Cloud and the Milky Way, since they can provide…

2021 Monthly Notices of the Royal Astronomical Society
eHST 14
Mars3DNet: CNN-Based High-Resolution 3D Reconstruction of the Martian Surface from Single Images
DOI: 10.3390/rs13050839 Bibcode: 2021RemS...13..839C

Liu, Wai Chung; Wu, Bo; Chen, Zeyu

Three-dimensional (3D) surface models, e.g., digital elevation models (DEMs), are important for planetary exploration missions and scientific research. Current DEMs of the Martian surface are mainly generated by laser altimetry or photogrammetry, which have respective limitations. Laser altimetry cannot produce high-resolution DEMs; photogrammetry…

2021 Remote Sensing
MEx 14
[C II] 158 µm line emission from Orion A I. A template for extragalactic studies?
DOI: 10.1051/0004-6361/202140804 Bibcode: 2021A&A...651A.111P

Wolfire, M. G.; Teyssier, D.; Goicoechea, J. R. +10 more

Context. The [C II] 158 µm fine-structure line is one of the dominant coolants of the neutral interstellar medium. It is hence one of the brightest far-infrared (FIR) emission lines and can be observed not only in star-forming regions throughout the Galaxy, but also in the diffuse interstellar medium and in distant galaxies. [C II] line emis…

2021 Astronomy and Astrophysics
Herschel 14
Spectro-imagery of an active tornado-like prominence: Formation and evolution
DOI: 10.1051/0004-6361/202140976 Bibcode: 2021A&A...653A..94B

Barczynski, Krzysztof; Schmieder, Brigitte; Labrosse, Nicolas +3 more

Context. The dynamical nature of fine structures in prominences remains an open issue, including rotating flows in tornado prominences. While the Atmospheric Imaging Assembly imager aboard the Solar Dynamics Observatory allowed us to follow the global structure of a tornado-like prominence for five hours, the Interface Region Imaging Spectrograph,…

2021 Astronomy and Astrophysics
IRIS 14