Search Publications

The Distribution Function of the Average Iron Charge State at 1 AU: From a Bimodal Wind to ICME Identification
DOI: 10.1007/s11207-020-01727-8 Bibcode: 2020SoPh..295..156L

Cid, C.; Larrodera, C.

We aim to investigate the distribution function of the iron charge state, at 1 AU to check if it corresponds to a bimodal wind. We use data from the Solar Wind Ion Composition Spectrometer (SWICS) instrument on board the Advanced Composition Explorer (ACE) along 20 years. We propose the bi-Gaussian function as the probability distribution function…

2020 Solar Physics
SOHO 2
A search for variable stars in the four open star clusters
DOI: 10.1007/s12036-020-09628-9 Bibcode: 2020JApA...41...13D

Bisht, D.; Rangwal, Geeta; Yadav, R. K. S. +3 more

We present a CCD photometric survey for the search of variable stars in four open clusters namely Berkeley 69, King 5, King 7 and Berkeley 20. The time series observations were carried out for 1 and/or 2 nights for each of the clusters in the year 1998, which have led to identify nineteen variable stars in these clusters. Out of these 19 variable …

2020 Journal of Astrophysics and Astronomy
Gaia 2
Variability and transient search in the SUDARE-VOICE field: a new method to extract the light curves
DOI: 10.1093/mnras/staa558 Bibcode: 2020MNRAS.493.3825L

Pignata, Giuliano; Vaccari, Mattia; Paolillo, Maurizio +12 more

The VLT Survey Telescope (VST) Optical Imaging of the CDFS and ES1 Fields Survey, in synergy with the SUDARE survey, is a deep optical ugri imaging of the CDFS and ES1 fields using the VST. The observations for the CDFS field comprise about 4.38 deg2 down to r ∼ 26 mag. The total on-sky time spans over 4 yr in this field, distributed ov…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 2
On Making Magnetic-flux-rope Ω Loops for Solar Bipolar Magnetic Regions of All Sizes by Convection Cells
DOI: 10.3847/2041-8213/abbade Bibcode: 2020ApJ...902L..35M

Tiwari, Sanjiv K.; Panesar, Navdeep K.; Moore, Ronald L. +1 more

We propose that the flux-rope Ω loop that emerges to become any bipolar magnetic region (BMR) is made by a convection cell of the Ω-loop's size from initially horizontal magnetic field ingested through the cell's bottom. This idea is based on (1) observed characteristics of BMRs of all spans (∼1000 to ∼200,000 km), (2) a well-known simulation of t…

2020 The Astrophysical Journal
Hinode 2
Prolonged, Weak C1.2 Flares: A Source of Protons and Electrons
DOI: 10.1134/S0016793220060067 Bibcode: 2020Ge&Ae..60..699G

Struminskii, A. B.; Grigor'eva, I. Yu.; Shakhovskaya, A. N.

Two proton events (>100 MeV; GOES, ACS SPI) associated with weak flares (C1.2, GOES class) in the soft X-ray range that occurred on November 26, 2011, and September 29, 2013, are analyzed. These events were accompanied by significant fluxes of relativistic electrons (>1 MeV; SOHO EPHIN) in the interplanetary space. The time profiles of these…

2020 Geomagnetism and Aeronomy
SOHO 2
Emission-line Data Cubes of the HH 32 Stellar Jet
DOI: 10.3847/1538-3881/abadfa Bibcode: 2020AJ....160..165H

Hartigan, Patrick; Neill, James D.; Hillenbrand, Lynne A. +5 more

We analyze data cubes of over 60 emission lines in the HH 32 stellar jet acquired with the Keck Cosmic Web Imager (KCWI). The data cover the less explored blue portion of the spectrum between 3586 and 6351 Å and have both high spectral (R ∼ 10,000) and spatial (≲1″) resolution. The study includes all three major ionization states of oxygen, three …

2020 The Astronomical Journal
Gaia eHST 2
Ionized gas in the NGC 5253 supernebula: high spatial and spectral resolution observations with the JVLA and TEXES
DOI: 10.1093/mnras/staa1819 Bibcode: 2020MNRAS.497.1675B

Beck, Sara C.; Liu, Hauyu Baobab; Ho, Paul T. P. +4 more

The youngest, closest, and most compact embedded massive star cluster known excites the supernebula in the nearby dwarf galaxy NGC 5253. It is a crucial target and test case for studying the birth and evolution of the most massive star clusters. We present observations of the ionized gas in this source with high spatial and spectral resolution. Th…

2020 Monthly Notices of the Royal Astronomical Society
eHST 2
Swift/XRT, Chandra, and XMM-Newton observations of IGR J17091-3624 as it returns into quiescence
DOI: 10.1093/mnras/staa2009 Bibcode: 2020MNRAS.497.1115P

Court, J. M. C.; Altamirano, D.; Degenaar, N. +4 more

IGR J17091-3624 is a low-mass X-ray binary (LMXB), which received wide attention from the community thanks to its similarities with the bright black hole system GRS 1915+105. Both systems exhibit a wide range of highly structured X-ray variability during outburst, with time-scales from few seconds to tens of minutes, which make them unique in the …

2020 Monthly Notices of the Royal Astronomical Society
XMM-Newton 2
A Survey of Venus Shock Crossings Dominated by Kinematic Relaxation
DOI: 10.1029/2020JA028256 Bibcode: 2020JGRA..12528256P

Pope, S. A.

Collisionless shocks are one of the most effective particle accelerators in the known universe. Even low Mach number shocks could have a significant role in particle heating and acceleration. Theory suggests that kinematic collisionless relaxation, the process whereby a downstream nongyroptopic ion population becomes thermalized through collisionl…

2020 Journal of Geophysical Research (Space Physics)
VenusExpress 2
A spectroscopic, photometric, polarimetric, and radio study of the eclipsing polar UZ Fornacis: the first simultaneous SALT and MeerKAT observations
DOI: 10.1093/mnras/staa080 Bibcode: 2020MNRAS.492.4298K

Hewitt, D. M.; Pretorius, M. L.; Woudt, P. A. +17 more

We present phase-resolved spectroscopy, photometry, and circular spectropolarimetry of the eclipsing polar UZ Fornacis. Doppler tomography of the strongest emission lines using the inside-out projection revealed the presence of three emission regions: from the irradiated face of the secondary star, the ballistic stream and the threading region, an…

2020 Monthly Notices of the Royal Astronomical Society
Gaia 2