Search Publications

DeGaS-MC: Dense Gas Survey in the Magellanic Clouds. I. An APEX survey of HCO+ and HCN(2-1) toward the LMC and SMC
DOI: 10.1051/0004-6361/202038641 Bibcode: 2020A&A...643A..63G

Immer, K.; Lebouteiller, V.; Madden, S. C. +9 more

Context. Understanding the star-forming processes is key to understanding the evolution of galaxies. Investigating star formation requires precise knowledge of the properties of the dense molecular gas complexes where stars form and a quantification of how they are affected by the physical conditions to which they are exposed. The proximity, low m…

2020 Astronomy and Astrophysics
Herschel 14
Newly Improved Ionization Corrections for the Neutral Interstellar Medium: Enabling Accurate Abundance Determinations in Star-forming Galaxies throughout the Universe
DOI: 10.3847/1538-4357/ab77c6 Bibcode: 2020ApJ...892...19H

Hernandez, Svea; Aloisi, Alessandra; James, Bethan L. +4 more

Studies measuring the chemical abundances of the neutral gas in star-forming galaxies (SFGs) require ionization correction factors (ICFs) to accurately measure their metal contents. In the work presented here, we calculate newly improved ICFs for a sample of SFGs. These new corrections include both the contaminating ionized gas along the line of s…

2020 The Astrophysical Journal
eHST 14
On the Motion of Stars in the Pleiades According to Gaia DR2 Data
DOI: 10.1134/S1990341320040045 Bibcode: 2020AstBu..75..407D

Danilov, V. M.; Seleznev, A. F.

—Several parameters of the Pleiades cluster were estimated. We used Gaia DR2 data on the coordinates, proper motions, and radial velocities of stars in regions with radius d° =2.5° and size 60° × 60° around the cluster center. Based on data on stars with magnitudes mG ≤ 18m, we constructed a map and profile of the density, lu…

2020 Astrophysical Bulletin
Gaia 14
The High Helium Abundance and Charge States of the Interplanetary CME and Its Material Source on the Sun
DOI: 10.3847/2041-8213/abb083 Bibcode: 2020ApJ...900L..18F

Harrison, R. A.; Davies, J. A.; Barnes, D. +5 more

Identifying the source of the material within coronal mass ejections (CMEs) and understanding CME onset mechanisms are fundamental issues in solar and space physics. Parameters relating to plasma composition, such as charge states and He abundance (AHe), may be different for plasmas originating from differing processes or regions on the…

2020 The Astrophysical Journal
IRIS SOHO 14
Hot Subdwarf All Southern Sky Fast Transit Survey with the Evryscope
DOI: 10.3847/1538-4357/ab64f3 Bibcode: 2020ApJ...890..126R

Law, Nicholas M.; Németh, Péter; Glazier, Amy +6 more

We have conducted a survey of candidate hot subdwarf (HSD) stars in the southern sky searching for fast transits, eclipses, and sinusoidal-like variability in the Evryscope light curves. The survey aims to detect transit signals from Neptune-size planets to gas giants, and eclipses from M-dwarfs and brown dwarfs. The other variability signals are …

2020 The Astrophysical Journal
Gaia 14
The discovery of lambda Bootis stars - the Southern Survey II
DOI: 10.1093/mnras/staa2347 Bibcode: 2020MNRAS.499.2701M

Bedding, Timothy R.; Murphy, Simon J.; Gray, Richard O. +3 more

The λ Boo stars are chemically peculiar A-type stars whose abundance anomalies are associated with the accretion of metal-poor material. We searched for λ Boo stars in the Southern hemisphere in a targeted spectroscopic survey of metal-weak and emission-line stars. Obtaining spectra for 308 stars and classifying them on the MK system, we found or …

2020 Monthly Notices of the Royal Astronomical Society
Gaia 14
Comparison of simulated backgrounds with in-orbit observations for HE, ME, and LE onboard Insight-HXMT
DOI: 10.1007/s10509-020-03873-8 Bibcode: 2020Ap&SS.365..158Z

Li, Gang; Li, Xiaobo; Tuo, Youli +10 more

Insight-HXMT, the first X-ray astronomical satellite in China, aims to reveal new sources in the Galaxy and to study fundamental physics of X-ray binaries from 1 to 250 keV. It has three collimated telescopes, the High Energy X-ray telescope (HE), the Medium Energy X-ray telescope (ME), and the Low Energy X-ray telescope (LE). Before the launch, i…

2020 Astrophysics and Space Science
INTEGRAL 14
Searching for the near-infrared counterpart of Proxima c using multi-epoch high-contrast SPHERE data at VLT
DOI: 10.1051/0004-6361/202037594 Bibcode: 2020A&A...638A.120G

Ménard, F.; Henning, T.; Brandner, W. +43 more

Context. Proxima Centauri is the closest star to the Sun and it is known to host an Earth-like planet in its habitable zone; very recently a second candidate planet was proposed based on radial velocities. At quadrature, the expected projected separation of this new candidate is larger than 1 arcsec, making it a potentially interesting target for …

2020 Astronomy and Astrophysics
Gaia 14
Jupiter's X-ray Emission During the 2007 Solar Minimum
DOI: 10.1029/2019JA027219 Bibcode: 2020JGRA..12527219D

Jackman, C. M.; Paranicas, C.; Ness, J. -U. +22 more

The 2007-2009 solar minimum was the longest of the space age. We present the first of two companion papers on Chandra and XMM-Newton X-ray campaigns of Jupiter through February-March 2007. We find that low solar X-ray flux during solar minimum causes Jupiter's equatorial regions to be exceptionally X-ray dim (0.21 GW at minimum; 0.76 GW at maximum…

2020 Journal of Geophysical Research (Space Physics)
Hinode 14
Chandra and XMM-Newton observations of A2256: cold fronts, merger shocks, and constraint on the IC emission
DOI: 10.1093/mnras/staa2320 Bibcode: 2020MNRAS.497.4704G

Rudnick, Lawrence; Finoguenov, Alexis; Clarke, Tracy E. +13 more

We present the results of deep Chandra and XMM-Newton observations of a complex merging galaxy cluster Abell 2256 (A2256) that hosts a spectacular radio relic (RR). The temperature and metallicity maps show clear evidence of a merger between the western subcluster (SC) and the primary cluster (PC). We detect five X-ray surface brightness edges. Th…

2020 Monthly Notices of the Royal Astronomical Society
XMM-Newton 14