Search Publications

An Atlas of Coronal Electron Density at 5R . II. A Spherical Harmonic Method for Density Reconstruction
DOI: 10.3847/1538-4365/ab125d Bibcode: 2019ApJS..242....3M

Morgan, Huw

This is the second of a series of three papers that present a methodology with the aim of creating a set of maps of the coronal density over a period of many years. This paper describes a method for reconstructing the coronal electron density based on spherical harmonics. By assuming a radial structure to the corona at the height of interest, line…

2019 The Astrophysical Journal Supplement Series
SOHO 18
Constraints on Uranus's haze structure, formation and transport
DOI: 10.1016/j.icarus.2019.05.018 Bibcode: 2019Icar..333....1T

Wong, Michael H.; Irwin, Patrick G. J.; Teanby, Nicholas A. +4 more

Microphysical simulations have been performed to constrain the formation and structure of haze in Uranus's atmosphere. These simulations were coupled to a radiative-transfer code to fit observations performed by the SINFONI Integral Field Unit Spectrometer on the Very Large Telescope (VLT) and by the Wide Field Camera 3 (WFC3) of the Hubble Space …

2019 Icarus
eHST 18
Spectroscopic and Stereoscopic Observations of the Solar Jets
DOI: 10.3847/1538-4357/ab530c Bibcode: 2019ApJ...887..154L

Feng, Li; Lu, Lei; Gan, Weiqun +3 more

We present a comprehensive study of a series of recurrent jets that occurred at the periphery of the NOAA active region 12114 on 2014 July 7. These jets were found to share the same source region and exhibited rotational motions as they propagated outward. The multiwavelength imaging observations made by the AIA and IRIS telescopes reveal that som…

2019 The Astrophysical Journal
IRIS 18
The little dippers: transits of star-grazing exocomets?
DOI: 10.1093/mnras/sty3289 Bibcode: 2019MNRAS.483.3579A

Hirano, T.; Vanderburg, A.; Ansdell, M. +9 more

We describe EPIC 205718330 and EPIC 235240266, two systems identified in the K2 data whose light curves contain episodic drops in brightness with shapes and durations similar to those of the young `dipper' stars, yet shallower by ∼1-2 orders of magnitude. These `little dippers' have diverse profile shapes with durations of ≃0.5-1.0 d and depths of…

2019 Monthly Notices of the Royal Astronomical Society
Gaia 18
A flat trend of star formation rate with X-ray luminosity of galaxies hosting AGN in the SCUBA-2 Cosmology Legacy Survey
DOI: 10.1093/mnras/stz1093 Bibcode: 2019MNRAS.486.4320R

Geach, James E.; Martin, Garreth; Stevens, Jason +1 more

Feedback processes from active galactic nuclei (AGN) are thought to play a crucial role in regulating star formation in massive galaxies. Previous studies using Herschel have resulted in conflicting conclusions as to whether star formation is quenched, enhanced, or not affected by AGN feedback. We use new deep 850 µm observations from the SC…

2019 Monthly Notices of the Royal Astronomical Society
Herschel 18
Comparative study of photo-produced ionosphere in the close environment of comets
DOI: 10.1051/0004-6361/201833517 Bibcode: 2019A&A...630A..47B

Galand, M.; Beth, A.; Heritier, K. L.

Context. The Giotto and Rosetta missions gave us the unique opportunity of probing the close environment of cometary ionospheres of 1P/Halley (1P) and 67P/Churyumov-Gerasimenko (67P). The plasma conditions encountered at these two comets were very different from each other, which mainly stem from the different heliocentric distances, which drive p…

2019 Astronomy and Astrophysics
Rosetta 18
Influence of inelastic collisions with hydrogen atoms on the non-local thermodynamic equilibrium line formation for Fe I and Fe II in the 1D model atmospheres of late-type stars
DOI: 10.1051/0004-6361/201935753 Bibcode: 2019A&A...631A..43M

Yakovleva, S. A.; Belyaev, A. K.; Sitnova, T. +1 more

Context. Iron plays a crucial role in studies of late-type stars. In their atmospheres, neutral iron is the minority species, and lines of Fe I are subject to the departures from local thermodynamic equilibrium (LTE). In contrast, one believes that LTE is a realistic approximation for Fe II lines. The main source of the uncertainties in the non-LT…

2019 Astronomy and Astrophysics
Gaia eHST 18
A merger shock in Abell 1367
DOI: 10.1093/mnrasl/slz049 Bibcode: 2019MNRAS.486L..36G

Jones, Christine; Rudnick, Lawrence; Fossati, Matteo +10 more

Multiwavelength observations show that Abell 1367 (A1367) is a dynamically young cluster, with at least two subclusters merging along the SE-NW direction. With the wide-field XMM-Newton mosaic of A1367, we discover a previously unknown merger shock at the NW edge of the cluster. We estimate the shock Mach number from the density and temperature ju…

2019 Monthly Notices of the Royal Astronomical Society
XMM-Newton 18
Storms or systematics? The changing secondary eclipse depth of WASP-12b
DOI: 10.1093/mnras/stz966 Bibcode: 2019MNRAS.486.2397H

de Mooij, Ernst J. W.; Gibson, Neale P.; Watson, Christopher A. +4 more

WASP-12b is one of the most well-studied transiting exoplanets, as its highly inflated radius and its 1.1 d orbit around a G0-type star make it an excellent target for atmospheric categorization through observation during its secondary eclipse. We present two new secondary eclipse observations of WASP-12b, acquired an year apart with the Wide Fiel…

2019 Monthly Notices of the Royal Astronomical Society
eHST 18
ARGOS at the LBT. Binocular laser guided ground-layer adaptive optics
DOI: 10.1051/0004-6361/201833716 Bibcode: 2019A&A...621A...4R

Genzel, R.; Quirrenbach, A.; Beckmann, U. +48 more

Having completed its commissioning phase, the Advanced Rayleigh guided Ground-layer adaptive Optics System (ARGOS) facility is coming online for scientific observations at the Large Binocular Telescope (LBT). With six Rayleigh laser guide stars in two constellations and the corresponding wavefront sensing, ARGOS corrects the ground-layer distortio…

2019 Astronomy and Astrophysics
eHST 18