Search Publications

Signatures of Cold Ions in a Kinetic Simulation of the Reconnecting Magnetopause
DOI: 10.1029/2018JA026343 Bibcode: 2019JGRA..124.2497D

Lavraud, B.; Toledo-Redondo, S.; Aunai, N. +2 more

At the Earth's magnetopause, a low-energy ion population of ionospheric origin is commonly observed at the magnetospheric side. In this work we use a 2-D fully kinetic simulation to identify several original signatures related to the dynamics of cold ions involved in magnetic reconnection at the asymmetric dayside magnetopause. We identify several…

2019 Journal of Geophysical Research (Space Physics)
Cluster 13
On the Origin of the Scatter in the Red Sequence: An Analysis of Four CLASH Clusters
DOI: 10.3847/1538-4357/ab0d84 Bibcode: 2019ApJ...875...16C

Donahue, Megan; Kelson, Daniel D.; Moustakas, John +1 more

In clusters of galaxies, the red sequence is believed to be a consequence of a correlation between stellar mass and chemical abundances, with more massive galaxies being more metal-rich and, as a consequence, redder. However, there is a color scatter around the red sequence that holds even with precision photometry, implying that the galaxy popula…

2019 The Astrophysical Journal
eHST 13
Star-forming galaxies at low-redshift in the SHARDS survey
DOI: 10.1051/0004-6361/201731670 Bibcode: 2019A&A...621A..52L

Mas-Hesse, J. M.; Hernán-Caballero, A.; Koekemoer, A. M. +13 more

Context. The physical processes driving the evolution of star formation (SF) in galaxies over cosmic time still present many open questions. Recent galaxy surveys allow now to study these processes in great detail at intermediate redshift (0 ≤ z ≤ 0.5).
Aims: We build a complete sample of star-forming galaxies and analyze their properties, re…

2019 Astronomy and Astrophysics
eHST 13
Equatorial Kelvin-like waves on slowly rotating and/or small-sized spheres: Application to Venus and Titan
DOI: 10.1016/j.icarus.2019.01.008 Bibcode: 2019Icar..322..103Y

Yamamoto, Masaru

Equatorial Kelvin waves, which have been observed in planetary fluids, produce superrotation and climatological variability. Although the meridional flow component is zero on Earth's beta-plane in the absence of background basic flow, it cannot be neglected on spheres in some planetary fluids when the Lamb parameter is small. For a vertically prop…

2019 Icarus
VenusExpress 13
AXS: A Framework for Fast Astronomical Data Processing Based on Apache Spark
DOI: 10.3847/1538-3881/ab2384 Bibcode: 2019AJ....158...37Z

Bellm, Eric C.; Golkhou, V. Zach; Jurić, Mario +5 more

We introduce AXS (Astronomy eXtensions for Spark), a scalable open-source astronomical data analysis framework built on Apache Spark, a widely used industry-standard engine for big-data processing. Building on capabilities present in Spark, AXS aims to enable querying and analyzing almost arbitrarily large astronomical catalogs using familiar Pyth…

2019 The Astronomical Journal
Gaia 13
The UV spectral slope β and stellar population of most active star-forming galaxies at z ∼ 4
DOI: 10.1093/pasj/psz024 Bibcode: 2019PASJ...71...51Y

Yamada, Toru; Yamanaka, Satoshi

We investigate a stellar population of star-forming galaxies at z ∼ 4 by focusing on the slope of their rest-frame ultraviolet (UV) continuum, β, where fλ ∝ λβ. We investigate a sample of bright Lyman break galaxies (LBGs) with i' ≤ 26.0 in the Subaru/XMM-Newton Deep Survey field by using a spectral energy distribution fittin…

2019 Publications of the Astronomical Society of Japan
eHST 13
Galaxies of the z ∼ 2 Universe. I. Grism-selected Rest-frame Optical Emission-line Galaxies
DOI: 10.3847/1538-4357/ab108a Bibcode: 2019ApJ...875..152B

Yang, Guang; Schneider, Donald P.; Gronwall, Caryl +6 more

Euclid, the Wide Field Infrared Survey Telescope, and the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) will make emission-line selected galaxies the largest observed constituent in the z > 1 universe. However, we only have a limited understanding of the physical properties of galaxies selected via their Lyα or rest-frame optical emiss…

2019 The Astrophysical Journal
eHST 13
Angular Sizes, Radii, and Effective Temperatures of B-type Stars from Optical Interferometry with the CHARA Array
DOI: 10.3847/1538-4357/ab04b2 Bibcode: 2019ApJ...873...91G

Gies, Douglas R.; Schaefer, Gail H.; Huber, Daniel +2 more

We present interferometric observations of 25 spectral type-B stars that were made with the Precision Astronomical Visible Observations and the CLassic Interferometry with Multiple Baselines beam combiners at the Center for High Angular Resolution Astronomy Array (CHARA). The observations provide the angular sizes of these stars with an average er…

2019 The Astrophysical Journal
Gaia IUE 13
Super Metal-rich Stars in the LAMOST Survey: A Test on Radial Migration
DOI: 10.3847/1538-3881/ab5283 Bibcode: 2019AJ....158..249C

Tian, H.; Zhao, G.; Chen, Y. Q. +5 more

Super metal-rich stars with [Fe/H] > 0.4 are selected from LAMOST DR6, and two groups, the blue and the red, are found in the T eff versus logg diagram with a temperature gap between them. In combination with Gaia DR2, stellar positions, velocities, and orbits are calculated, and spatial distributions, kinematical properties, and orb…

2019 The Astronomical Journal
Gaia 13
Kinematic signatures of cluster formation from cool collapse in the Lagoon Nebula cluster NGC 6530
DOI: 10.1093/mnras/stz2303 Bibcode: 2019MNRAS.489.2694W

Parker, Richard J.; Wright, Nicholas J.

We examine the mass dependence of the velocity dispersion of stars in the young cluster NGC 6530 to better understand how it formed. Using a large sample of members we find that the proper motion velocity dispersion increases with stellar mass. While this trend is the opposite of that predicted if the cluster were developing energy equipartition, …

2019 Monthly Notices of the Royal Astronomical Society
Gaia 13