Search Publications

Statistical Characteristics on SEPs, Radio-Loud CMEs, Low Frequency Type II and Type III Radio Bursts Associated with Impulsive and Gradual Flares
DOI: 10.1007/s11038-020-09533-9 Bibcode: 2020EM&P..123...61K

Prakash, O.; Shanmugaraju, A.; Kim, R. -S. +1 more

We have statistically analyzed a set of 115 low frequency (Deca-Hectometer wavelengths range) type II and type III bursts associated with major Solar Energetic Particle (SEP: Ep > 10 MeV) events and their solar causes such as solar flares and coronal mass ejections (CMEs) observed from 1997 to 2014. We classified them into two sets o…

2020 Earth Moon and Planets
SOHO 4
Inferring Contributions from Unresolved Point Sources to Diffuse Emissions Measured in UV Sky Surveys: General Method and SOHO/SWAN Case Study
DOI: 10.3847/1538-4357/ab9e6f Bibcode: 2020ApJ...899...48S

Bzowski, M.; Kubiak, M. A.; Kowalska-Leszczynska, I. +1 more

In observations of diffuse emissions like, e.g., the Lyα heliospheric glow, contributions to the observed signal from point sources (e.g., stars) are considered to be a contamination. There are relatively few bright point sources that are usually properly resolved and can be subtracted or masked. We present results of an analysis of the distributi…

2020 The Astrophysical Journal
IUE SOHO 4
Termination Shock as a Source of Unusual Solar Radio Bursts
DOI: 10.3847/1538-4357/abad9f Bibcode: 2020ApJ...901...65F

Chernov, Gennady; Fomichev, Valery

Using centimeter-wave and decimeter-wave solar radio spectral observations of the flares of 2003 November 18 and 2004 September 12, we have discussed two type-II-like bursts at the meter waves. The radio bursts show that the ordinary frequency drift from high to low frequencies slows down and stops, and a frequency drift from low to high frequenci…

2020 The Astrophysical Journal
SOHO 4
Infrared photometry of the dwarf nova V2051 Ophiuchi - II. The quiescent accretion disc and its spiral arms
DOI: 10.1093/mnras/stz3517 Bibcode: 2020MNRAS.492.1154B

Baptista, Raymundo; Wojcikiewicz, Eduardo

We report the analysis of time-series of infrared JHKs photometry of the dwarf nova V2051 Oph in quiescence with eclipse mapping techniques to investigate structures and the spectrum of its accretion disc. The light curves after removal of the ellipsoidal variations caused by the mass-donor star show a double-wave modulation signalling …

2020 Monthly Notices of the Royal Astronomical Society
Gaia 4
Waves propagation in network and inter-network bright points channels between the chromosphere and transition regions with IRIS observations
DOI: 10.1007/s12036-020-09633-y Bibcode: 2020JApA...41...18Z

Zeighami, Sima; Tavabi, Ehsan; Amirkhanlou, Elnaz

The significance increase of the plasma temperature from the solar photosphere to the corona up to 1MK is still unresolved. One of the candidates for this issue is waves and instabilities in the solar plasma. It was suggested that the energy of these waves could heat the solar atmosphere to transition-region (TR) and corona. Despite many recent ki…

2020 Journal of Astrophysics and Astronomy
IRIS 4
Light-time effect detected in fourteen eclipsing binaries
DOI: 10.1051/0004-6361/202039243 Bibcode: 2020A&A...643A.130Z

Mašek, M.; Uhlař, R.; Zasche, P. +2 more

The available minima timings of 14 selected eclipsing binaries (V1297 Cas, HD 24105, KU Aur, GU CMa, GH Mon, AZ Vel, DI Lyn, DK Her, GQ Dra, V624 Her, V1134 Her, KIC 6187893, V1928 Aql, V2486 Cyg) were collected and analyzed. Using the automatic telescopes, surveys, and satellite data, we derived more than 2500 times of eclipses, accompanied with …

2020 Astronomy and Astrophysics
Gaia INTEGRAL 4
Photocenter Shift Effect in Double Stars of Gaia DR2 Database
DOI: 10.32023/0001-5237/70.1.2 Bibcode: 2020AcA....70...19L

Ling, J. F.; López Oriona, A.; Sánchez Sellero, C.

In order to check the performance of the Gaia satellite when detecting double stars, we attempted to discover a photocenter shift affecting Gaia's second data release (Gaia DR2). We analyzed data of bona-fide double stars from "Double and Multiple System Annex" catalog and matched them with the Gaia DR2 catalog. We tried to derive a relationship b…

2020 Acta Astronomica
Gaia 4
Near-Gaussian distributions for modelling discrete stellar velocity data with heteroskedastic uncertainties
DOI: 10.1093/mnras/staa2860 Bibcode: 2020MNRAS.499.5806S

Evans, N. Wyn; Sanders, Jason L.

The velocity distributions of stellar tracers in general exhibit weak non-Gaussianity encoding information on the orbital composition of a galaxy and the underlying potential. The standard solution for measuring non-Gaussianity involves constructing a series expansion (e.g. the Gauss-Hermite series) that can produce regions of negative probability…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 4
Rotational modulation and single g-mode pulsation in the B9pSi star HD 174356?
DOI: 10.1093/mnras/staa2433 Bibcode: 2020MNRAS.498..548M

Ilyin, I.; Järvinen, S.; Niemczura, E. +19 more

Chemically peculiar (CP) stars of the upper main sequence are characterized by specific anomalies in the photospheric abundances of some chemical elements. The group of CP2 stars, which encompasses classical Ap and Bp stars, exhibits strictly periodic light, spectral, and spectropolarimetric variations that can be adequately explained by the model…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 4
Gaia-assisted discovery of a detached low-ionisation BAL quasar with very large ejection velocities
DOI: 10.1051/0004-6361/201936957 Bibcode: 2020A&A...634A.111F

Milvang-Jensen, B.; Fynbo, J. P. U.; Christensen, L. +10 more

We report on the discovery of a peculiar broad absorption line (BAL) quasar identified in our Gaia-assisted survey of red quasars. The systemic redshift of this quasar was difficult to establish because of the absence of conspicuous emission lines. Based on deep and broad BAL troughs of at least Si IV, C IV, and Al III, a redshift of z = 2.41 was …

2020 Astronomy and Astrophysics
Gaia 4