Search Publications

Shock Properties and Associated Characteristics of Solar Energetic Particles in the 2017 September 10 Ground-level Enhancement Event
DOI: 10.3847/1538-4357/ac106b Bibcode: 2021ApJ...921...26Z

Jin, Meng; Liu, Ying D.; Xu, Xiaojun +3 more

The solar eruption on 2017 September 10 was accompanied by a fast coronal mass ejection (~3000 km s-1) and produced a ground-level enhancement (GLE) event at Earth. Multiple-viewpoint remote sensing observations are used to find the three-dimensional (3D) structure of the shock. We determine the shock parameters by combining the 3D shoc…

2021 The Astrophysical Journal
SOHO 8
Local Active Galactic Nuclei with Large Broad-Hα Variability Reside in Red Galaxies
DOI: 10.3847/1538-4357/abf82c Bibcode: 2021ApJ...915...63L

Wang, Jing; Liu, Wen-Juan; Yao, Su +4 more

Inspired by our serendipitous discovery of six active galactic nuclei (AGNs) with varying broad-Hα fluxes over years from our search for intermediate-mass black holes (IMBHs), we conduct a systematic investigation of changing-look (CL) and large-variability AGNs. We collect all the CL AGNs at z < 0.15 and the reverberation-mapped AGNs with stro…

2021 The Astrophysical Journal
XMM-Newton 8
Pebbles in an embedded protostellar disk: the case of CB 26
DOI: 10.1051/0004-6361/202039536 Bibcode: 2021A&A...646A..18Z

Henning, Thomas; Zhang, Chuan-Peng; Launhardt, Ralf +2 more

Context. Planetary cores are thought to form in proto-planetary disks via the growth of dusty solid material. However, it is unclear how early this process begins.
Aims: We study the physical structure and grain growth in the edge-on disk that surrounds the ≈1 Myr old low-mass (≈0.55 M) protostar embedded in the Bok globule CB26 t…

2021 Astronomy and Astrophysics
Herschel 8
Shock Mach Number Estimates Using Incomplete Measurements
DOI: 10.1029/2021JA029519 Bibcode: 2021JGRA..12629519G

Russell, Christopher T.; Dimmock, Andrew P.; Gedalin, Michael

The Mach number is one of the most important parameters of collisionless shocks. The accuracy of its observational determination is compromised by several complications. Incomplete measurements of plasma parameters significantly contribute to the uncertainty, along with the errors of the normal determination. A set of CLUSTER observed shocks is an…

2021 Journal of Geophysical Research (Space Physics)
Cluster 8
Magnetic Topology of Actively Evolving and Passively Convecting Structures in the Turbulent Solar Wind
DOI: 10.1103/PhysRevLett.126.125101 Bibcode: 2021PhRvL.126l5101H

Chapman, S. C.; Hnat, B.; Watkins, N. W.

Multipoint in situ observations of the solar wind are used to identify the magnetic topology and current density of turbulent structures. We find that at least 35% of all structures are both actively evolving and carrying the strongest currents, actively dissipating, and heating the plasma. These structures are comprised of ∼1 /5 3D plasmoids, ∼3 …

2021 Physical Review Letters
Cluster 8
Probing galactic double-mode RR Lyrae stars against Gaia EDR3
DOI: 10.1051/0004-6361/202141100 Bibcode: 2021A&A...653A..61K

Kovacs, Geza; Karamiqucham, Behrooz

Context. Classical double-mode pulsators (RR Lyrae stars and δ Cepheids) are important because of their simultaneous pulsation in low-order radial modes. This enables us to place stringent constraints on their physical parameters.
Aims: We use 30 bright galactic double-mode RR Lyrae (RRd) stars to estimate their luminosities and compare these…

2021 Astronomy and Astrophysics
Gaia 8
Cross-Scale Energy Transport in Space Plasmas: Applications to the Magnetopause Boundary
DOI: 10.1002/9781119815624.ch7 Bibcode: 2021GMS...259..109N

Nykyri, Katariina; Ma, Xuanye; Johnson, Jay

2021 Magnetospheres in the Solar System
Cluster DoubleStar 8
15 years of galactic surveys and hard X-ray background measurements
DOI: 10.1016/j.newar.2021.101612 Bibcode: 2021NewAR..9201612K

Tsygankov, Sergey S.; Sunyaev, Rashid; Kuulkers, Erik +15 more

The INTEGRAL hard X-ray surveys have proven to be of fundamental importance. INTEGRAL has mapped the Galactic plane with its large field of view and excellent sensitivity. Such hard X-ray snapshots of the whole Milky Way on a time scale of a year are beyond the capabilities of past and current narrow-FOV grazing incidence X-ray telescopes. By expa…

2021 New Astronomy Reviews
INTEGRAL 8
The Magnetosheath
DOI: 10.1002/9781119815624.ch9 Bibcode: 2021GMS...259..137N

Plaschke, Ferdinand; Vörös, Zoltán; Narita, Yasuhito

2021 Magnetospheres in the Solar System
Cluster 8
Physical and Chemical Structure of the Disk and Envelope of the Class 0/I Protostar L1527
DOI: 10.3847/1538-4357/abd1db Bibcode: 2021ApJ...908..108F

Flock, Mario; Terebey, Susan; Isella, Andrea +3 more

Submillimeter spectral line and continuum emission from the protoplanetary disks and envelopes of protostars is a powerful probe of their structure, chemistry, and dynamics. Here we present a benchmark study of our modeling code, RadChemT, that for the first time uses a chemical model to reproduce ALMA C18O (2-1), and CARMA 12

2021 The Astrophysical Journal
Herschel 8