Search Publications
New Martian valley network volume estimate consistent with ancient ocean and warm and wet climate
Howard, Alan D.; Luo, Wei; Cang, Xuezhi
The volume of Martian valley network (VN) cavity and the amount of water needed to create the cavity by erosion are of significant importance for understanding the early Martian climate, the style and rate of hydrologic cycling, and the possibility of an ancient ocean. However, previous attempts at estimating these two quantities were based on sel…
A direct examination of the dynamics of dipolarization fronts using MMS
Russell, C. T.; Fazakerley, A. N.; Owen, C. J. +13 more
Energy conversion on the dipolarization fronts (DFs) has attracted much research attention through the suggestion that intense current densities associated with DFs can modify the more global magnetotail current system. The current structures associated with a DF are at the scale of one to a few ion gyroradii, and their duration is comparable to a…
Achievements and Challenges in the Science of Space Weather
Veronig, Astrid; Balogh, André; Koskinen, Hannu E. J. +3 more
In June 2016 a group of 40 space weather scientists attended the workshop on Scientific Foundations of Space Weather at the International Space Science Institute in Bern. In this lead article to the volume based on the talks and discussions during the workshop we review some of main past achievements in the field and outline some of the challenges…
Supernova progenitors, their variability and the Type IIP Supernova ASASSN-16fq in M66
Kochanek, C. S.; Stanek, K. Z.; Dong, Subo +10 more
We identify a pre-explosion counterpart to the nearby Type IIP supernova ASASSN-16fq (SN 2016cok) in archival Hubble Space Telescope data. The source appears to be a blend of several stars that prevents obtaining accurate photometry. However, with reasonable assumptions about the stellar temperature and extinction, the progenitor almost certainly …
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…
3D stellar reddening map from 2MASS photometry: An improved version
Gontcharov, G. A.
An improved version of the 3D stellar reddening map in a space with a radius of 1200 pc around the Sun and within 600 pc of the Galactic midplane is presented. As in the previous 2010 and 2012 versions of the map, photometry with an accuracy better than 0.05 m in the J and Ks bands for more than 70 million stars from the 2MASS catalogu…
Cosmological constraints on the neutrino mass including systematic uncertainties
Couchot, F.; Henrot-Versillé, S.; Perdereau, O. +4 more
When combining cosmological and oscillations results to constrain the neutrino sector, the question of the propagation of systematic uncertainties is often raised. We address this issue in the context of the derivation of an upper bound on the sum of the neutrino masses (Σmν) with recent cosmological data. This work is performed within …
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…