Search Publications

Effects of Coronal Density and Magnetic Field Distributions on a Global Solar EUV Wave
DOI: 10.3847/1538-4357/ab2055 Bibcode: 2019ApJ...878..106H

Wang, Rui; Yang, Zhongwei; Liu, Ying D. +4 more

We investigate a global extreme-ultraviolet (EUV) wave associated with a coronal mass ejection (CME)-driven shock on 2017 September 10. The EUV wave is transmitted by north- and south-polar coronal holes (CHs), which is observed by the Solar Dynamics Observatory (SDO) and Solar Terrestrial Relations Observatory A (STEREO-A) from opposite sides of …

2019 The Astrophysical Journal
SOHO 26
Classifying exoplanet candidates with convolutional neural networks: application to the Next Generation Transit Survey
DOI: 10.1093/mnras/stz2058 Bibcode: 2019MNRAS.488.5232C

Wheatley, Peter J.; Eigmüller, Philipp; Casewell, Sarah L. +13 more

Vetting of exoplanet candidates in transit surveys is a manual process, which suffers from a large number of false positives and a lack of consistency. Previous work has shown that convolutional neural networks (CNN) provide an efficient solution to these problems. Here, we apply a CNN to classify planet candidates from the Next Generation Transit…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 26
Origin of Radio-quiet Coronal Mass Ejections in Flare Stars
DOI: 10.3847/1538-4357/ab041b Bibcode: 2019ApJ...873....1M

Mullan, D. J.; Paudel, R. R.

Type II radio bursts are observed in the Sun in association with many coronal mass ejections (CMEs). In view of this association, there has been an expectation that, by scaling from solar flares to the flares that are observed on M dwarfs, radio emission analogous to solar type II bursts should be detectable in association with M dwarf flares. How…

2019 The Astrophysical Journal
SOHO 26
VIS3COS. II. Nature and nurture in galaxy structure and morphology
DOI: 10.1051/0004-6361/201935137 Bibcode: 2019A&A...630A..57P

van der Wel, Arjen; Sobral, David; Darvish, Behnam +7 more

We study the impact of local density and stellar mass on the structure and morphology of approximately 500 quiescent and star-forming galaxies from the VIMOS Spectroscopic Survey of a Superstructure in COSMOS (VIS3COS). We perform bulge-to-disc decomposition of the surface brightness profiles and find ∼41 ± 3% of > 1010 M<…

2019 Astronomy and Astrophysics
eHST 26
Mapping the stellar age of the Milky Way bulge with the VVV. II. Deep JKs catalog release based on PSF photometry
DOI: 10.1051/0004-6361/201935730 Bibcode: 2019A&A...629A...1S

Minniti, D.; Rejkuba, M.; Zoccali, M. +6 more

Context. The bulge represents the best compromise between old and massive Galactic components, and as such its study is a valuable opportunity to understand how the bulk of the Milky Way formed and evolved. In addition, being the only bulge in which we can individually resolve stars in all evolutionary sequences, the properties of its stellar cont…

2019 Astronomy and Astrophysics
Gaia 26
Spectral analysis of the extremely hot DA white dwarf PG 0948+534
DOI: 10.1093/mnras/sty3408 Bibcode: 2019MNRAS.483.5291W

Rauch, T.; Werner, K.; Reindl, N.

There is a striking paucity of hydrogen-rich (DA) white dwarfs (WDs) relative to their hydrogen-deficient (non-DA) counterparts at the very hot end of the WD cooling sequence. The three hottest known DAs (surface gravity log g ≥ 7.0) have effective temperatures around T_{eff} = 140 000 K, followed by only five objects in the range 104 000-120 000 …

2019 Monthly Notices of the Royal Astronomical Society
IUE eHST 26
The chemical structure of the very young starless core L1521E
DOI: 10.1051/0004-6361/201935568 Bibcode: 2019A&A...630A.136N

Nagy, Z.; Caselli, P.; Spezzano, S. +5 more

Context. L1521E is a dense starless core in Taurus that was found to have relatively low molecular depletion by earlier studies, thus suggesting a recent formation.
Aims: We aim to characterize the chemical structure of L1521E and compare it to the more evolved L1544 pre-stellar core.
Methods: We have obtained 2.5 × 2.5 arcminute maps to…

2019 Astronomy and Astrophysics
Herschel 26
A deep X-ray view of the bare AGN Ark 120. V. Spin determination from disc-Comptonisation efficiency method
DOI: 10.1051/0004-6361/201834448 Bibcode: 2019A&A...623A..11P

Stern, D.; Farrah, D.; Done, C. +13 more

Context. The spin of supermassive black holes (SMBH) in active galactic nuclei (AGN) can be determined from spectral signature(s) of relativistic reflection such as the X-ray iron Kα line profile, but this can be rather uncertain when the line of sight intersects the so-called warm absorber and/or other wind components as these distort the continu…

2019 Astronomy and Astrophysics
XMM-Newton eHST 26
The Swift UVOT Stars Survey. III. Photometry and Color-Magnitude Diagrams of 103 Galactic Open Clusters
DOI: 10.3847/1538-3881/ab21e1 Bibcode: 2019AJ....158...35S

Hagen, Lea M. Z.; Siegel, Michael H.; Porterfield, Blair L. +2 more

As part of the Swift/Ultraviolet-Optical Telescope Stars Survey, we present near-ultraviolet (NUV; 3000-1700 Å) point-source photometry for 103 Galactic open clusters. These data, taken over the span of the mission, provide a unique and unprecedented set of NUV point-source photometry on simple stellar populations. After applying a membership anal…

2019 The Astronomical Journal
Gaia 26
Greening of the brown-dwarf desert. EPIC 212036875b: a 51 MJ object in a 5-day orbit around an F7 V star
DOI: 10.1051/0004-6361/201935505 Bibcode: 2019A&A...628A..64P

Cochran, William D.; Endl, Michael; Redfield, Seth +55 more

Context. Although more than 2000 brown dwarfs have been detected to date, mainly from direct imaging, their characterisation is difficult due to their faintness and model-dependent results. In the case of transiting brown dwarfs, however, it is possible to make direct high-precision observations.
Aims: Our aim is to investigate the nature and…

2019 Astronomy and Astrophysics
Gaia 26