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Observational Evidence for the Associated Formation of Blobs and Raining Inflows in the Solar Corona
Davies, J. A.; Lavraud, B.; Kilpua, E. +6 more
The origin of the slow solar wind is still a topic of much debate. The continual emergence of small transient structures from helmet streamers is thought to constitute one of the main sources of the slow wind. Determining the height at which these transients are released is an important factor in determining the conditions under which the slow sol…
H2CO Distribution and Formation in the TW HYA Disk
Wilner, David J.; Cleeves, L. Ilsedore; Andrews, Sean M. +8 more
H2CO is one of the most readily detected organic molecules in protoplanetary disks. Yet its distribution and dominant formation pathway(s) remain largely unconstrained. To address these issues, we present ALMA observations of two H2CO lines ({3}12{--}{2}11 and {5}15{--}{4}14) at 0.″…
On the Relation between the In Situ Properties and the Coronal Sources of the Solar Wind
Lepri, S. T.; Zhao, L.; Zurbuchen, T. H. +4 more
We categorize the types of solar wind using a new classification scheme based on the location of the wind’s coronal source regions in the solar atmosphere and near-solar heliosphere. We first trace the solar wind measured by ACE/SWEPAM and SWICS from 1998 to 2011 at 1 au back to a 2.5{R}{{s}} solar surface using ballistic mapping at con…
Dense CO in Mrk 71-A: Superwind Suppressed in a Young Super Star Cluster
James, Bethan L.; Oey, M. S.; Reiter, Megan +4 more
We report the detection of CO(J=2-1) coincident with the super star cluster (SSC) Mrk 71-A in the nearby Green Pea analog galaxy, NGC 2366. Our observations with the Northern Extended Millimeter Array reveal a compact, ∼7 pc, molecular cloud whose mass ({10}5 {M}⊙ ) is similar to that of the SSC, consistent with a high star f…
Powerful H2 Line Cooling in Stephan’s Quintet. II. Group-wide Gas and Shock Modeling of the Warm H2 and a Comparison with [C II] 157.7 µm Emission and Kinematics
Boulanger, F.; Appleton, P. N.; Xu, C. K. +7 more
We map for the first time the two-dimensional H2 excitation of warm intergalactic gas in Stephan's Quintet on group-wide (50 × 35 kpc2) scales to quantify the temperature, mass, and warm H2 mass fraction as a function of position using Spitzer. Molecular gas temperatures are seen to rise (to T > 700 K) and the s…
A Probabilistic Approach to Fitting Period-luminosity Relations and Validating Gaia Parallaxes
Rix, Hans-Walter; Fouesneau, Morgan; Price-Whelan, Adrian M. +3 more
Pulsating stars, such as Cepheids, Miras, and RR Lyrae stars, are important distance indicators and calibrators of the “cosmic distance ladder,” and yet their period-luminosity-metallicity (PLZ) relations are still constrained using simple statistical methods that cannot take full advantage of available data. To enable optimal usage of data provid…
Challenging Some Contemporary Views of Coronal Mass Ejections. II. The Case for Absent Filaments
DeForest, C. E.; Howard, T. A.; Schneck, U. G. +1 more
When a coronal mass ejection (CME) appears in a coronagraph it often exhibits three parts. This “classic” three-part configuration consists of a bright leading edge, a dark circular- or teardrop-shaped cavity, and a bright core within the cavity. It is generally accepted that these are manifestations of coronal plasma pileup, the driving magnetic …
The Grism Lens-amplified Survey from Space (Glass). IX. The Dual Origin of Low-mass Cluster Galaxies as Revealed by New Structural Analyses
Schmidt, Kasper B.; Treu, Tommaso; Bradač, Maruša +10 more
Using deep Hubble Frontier Fields imaging and slitless spectroscopy from the Grism Survey from Space, we study 2200 cluster and 1748 field galaxies at 0.2≤slant z≤slant 0.7 to determine the impact of environment on galaxy size and structure at stellar masses {log}{M}* /{M}⊙ > 7.8, an unprecedented limit at these redshifts.…
Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields
Lee, Hyeseung; Yuen, Ka Ho; Cho, J. +1 more
On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility …
Critical Height of the Torus Instability in Two-ribbon Solar Flares
Wang, Yuming; Liu, Rui; Liu, Jiajia +5 more
We studied the background field for 60 two-ribbon flares of M-and-above classes during 2011-2015. These flares are categorized into two groups, I.e., eruptive and confined flares, based on whether a flare is associated with a coronal mass ejection or not. The background field of source active regions is approximated by a potential field extrapolat…