Search Publications

Investigation of ionospheric TEC anomalies caused by space weather conditions
DOI: 10.1007/s10509-020-03862-x Bibcode: 2020Ap&SS.365..150A

Alcay, Salih; Gungor, Merve

This study examines the influence of space weather conditions on ionospheric TEC variations at different latitudes around the world. According to the space weather condition indices (geomagnetic storm-activity indices, solar activity indices, magnetic field change indices, plasma density and proton flux indices) different time periods were chosen.…

2020 Astrophysics and Space Science
SOHO 10
Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids: Final Results
DOI: 10.3847/1538-4357/abc1f1 Bibcode: 2020ApJ...905...81E

Schaefer, Gail H.; Bond, Howard E.; Evans, Nancy Remage +13 more

Cepheids in multiple systems provide information on the outcome of the formation of massive stars. They can also lead to exotic end-stage objects. This study concludes our survey of 70 galactic Cepheids using the Hubble Space Telescope (HST) Wide Field Camera 3 (WFC3) with images at two wavelengths to identify companions closer than 5″. In the ent…

2020 The Astrophysical Journal
Gaia XMM-Newton eHST 10
Electric sails are potentially more effective than light sails near most stars
DOI: 10.1016/j.actaastro.2019.12.013 Bibcode: 2020AcAau.168..146L

Lingam, Manasvi; Loeb, Abraham

Electric sails are propulsion systems that generate momentum via the deflection of stellar wind particles through electric forces. Here, we investigate the relative merits of electric sails and light sails driven by stellar radiation pressure for F-, G-, K- and M-type stellar systems. We show that electric sails originating near M-dwarfs could att…

2020 Acta Astronautica
Ulysses 10
Physical characterization of double asteroid (617) Patroclus from 2007/2012 mutual events observations
DOI: 10.1016/j.icarus.2020.113990 Bibcode: 2020Icar..35213990B

Colas, F.; Berthier, J.; Pauwels, T. +20 more

We publish a set of 16 light curves of mutual events inside the synchronous system of the Jupiter Trojan (617) Patroclus. Patroclus is th only binary system of the six target asteroids of the forthcoming NASA Discovery-class mission Lucy. Determining the physical parameters of the system is therefore of primary importance in helping to plan the fl…

2020 Icarus
eHST 10
Probing UV-sensitive Pathways for CN and HCN Formation in Protoplanetary Disks with the Hubble Space Telescope
DOI: 10.3847/1538-3881/ab789a Bibcode: 2020AJ....159..168A

France, Kevin; Hoadley, Keri; Manara, Carlo F. +6 more

The UV radiation field is a critical regulator of gas-phase chemistry in surface layers of disks around young stars. In an effort to understand the relationship between photocatalyzing UV radiation fields and gas emission observed at infrared and submillimeter wavelengths, we present an analysis of new and archival Hubble Space Telescope (HST), Sp…

2020 The Astronomical Journal
eHST 10
Forward modelling the multiwavelength properties of active galactic nuclei: application to X-ray and WISE mid-infrared samples
DOI: 10.1093/mnras/staa2528 Bibcode: 2020MNRAS.499..710G

Ruiz, Angel; Georgakakis, Antonis; LaMassa, Stephanie M.

An empirical forward-modelling framework is developed to interpret the multiwavelength properties of active galactic nuclei (AGNs) and provide insights into the overlap and incompleteness of samples selected at different parts of the electromagnetic spectrum. The core of the model are observationally derived probabilites on the occupation of galax…

2020 Monthly Notices of the Royal Astronomical Society
XMM-Newton 10
The braking index of PSR B0540-69 and the associated pulsar wind nebula emission after spin-down rate transition
DOI: 10.1093/mnras/staa884 Bibcode: 2020MNRAS.494.1865W

Zhang, S. N.; Dai, Z. G.; Ge, M. Y. +6 more

In 2011 December, PSR B054-69 experienced a spin-down rate transition (SRT), after which the spin-down power of the pulsar increased by $\sim 36{{\ \rm per\ cent}}$. About 1000 d after the SRT, the X-ray luminosity of the associated pulsar wind nebula (PWN) was found to brighten by $32\pm 8{{\ \rm per\ cent}}$. After the SRT, the braking index n o…

2020 Monthly Notices of the Royal Astronomical Society
XMM-Newton 10
Persistent Emission Properties of SGR J1935+2154 during Its 2020 Active Episode
DOI: 10.3847/2041-8213/abcfc8 Bibcode: 2020ApJ...905L..31G

Göğüş, Ersin; Kouveliotou, Chryssa; Lin, Lin +6 more

We present detailed spectral and temporal characteristics of the persistent X-ray emission of SGR J1935+2154 based on our XMM-Newton and Chandra observations taken in the aftermath of its 2020 April burst storm, during which hundreds of energetic X-ray bursts were emitted, including one associated with an extraordinary fast radio burst. We clearly…

2020 The Astrophysical Journal
XMM-Newton 10
The nature of the photometric variability of HgMn stars: a test of simulated light curves of φ Phe against the TESS data
DOI: 10.1093/mnras/stz3564 Bibcode: 2020MNRAS.492.1834P

Krtička, Jiří; Korhonen, Heidi; Prvák, Milan

The inhomogeneous surface distribution of heavy elements is known to cause periodic light variability of magnetic chemically peculiar stars. It is unclear to what extent the same paradigm applies to mercury-manganese (HgMn) stars. We aim to model the photometric variability of the HgMn star φ Phe using abundance maps obtained from high-resolution …

2020 Monthly Notices of the Royal Astronomical Society
IUE 10
Herschel/PACS OH Spectroscopy of Seyfert, LINER, and Starburst Galaxies
DOI: 10.3847/1538-4357/abb8e0 Bibcode: 2020ApJ...905...57R

Spinoglio, Luigi; Fernández-Ontiveros, Juan Antonio; Malkan, Matthew A. +2 more

We investigated the 65, 71, 79, 84, 119, and 163 µm OH doublets of 178 local (0 < z < 0.35) galaxies. They were observed using the Herschel/Photoconductor Array Camera and Spectrometer, including Seyfert galaxies, low-ionization nuclear emission-line regions, and star-forming galaxies. We observe these doublets exclusively in absorptio…

2020 The Astrophysical Journal
Herschel 10