Search Publications

Earth's Magnetotail as the Reservoir of Accelerated Single and Multicharged Oxygen Ions Replenishing Radiation Belts
DOI: 10.1029/2020JA028217 Bibcode: 2021JGRA..12628217P

Malova, Helmi V.; Zelenyi, Lev M.; Panasyuk, Mikhail I. +4 more

Acceleration of single and multicharged oxygen ions in the perturbed Earth's magnetotail is investigated as the possible source of energetic heavy ions in the ring current. The numerical model is developed that allows evaluating the acceleration of oxygen ions O+ O+8 in two possible scenarios of characteristic perturbations: …

2021 Journal of Geophysical Research (Space Physics)
Cluster 2
Ti I lines at 2.2 µm as probes of the cooler regions of sunspots
DOI: 10.1051/0004-6361/202141447 Bibcode: 2021A&A...653A..91S

Solanki, S. K.; Castellanos Durán, J. S.; Tiwari, S. K. +1 more

Context. The sunspot umbra harbours the coolest plasma on the solar surface due to the presence of strong magnetic fields. The atomic lines that are routinely used to observe the photosphere have weak signals in the umbra and are often swamped by molecular lines. This makes it harder to infer the properties of the umbra, especially in the darkest …

2021 Astronomy and Astrophysics
Hinode 2
A Suzaku study of the low mass X-ray binary Aquila X-1 in the different states
DOI: 10.1016/j.jheap.2021.05.001 Bibcode: 2021JHEAp..31...12A

Abdelbar, Ahmed M.; Beheary, M. M.; Abdelfatah, Ahmed S. +1 more

We present a Suzaku X-ray study for the neutron star low mass X-ray binary Aquila X-1. The observations of the system carried out during three times in 2011 from October 18 to October 24, where the repeated X-ray transient Aquila X-1 was in the rising phase of the outburst. During this period the source was successfully detected in its different s…

2021 Journal of High Energy Astrophysics
Suzaku 2
Breaks in the X-Ray Spectra of High-redshift Blazars and the Intervening Medium
DOI: 10.3847/1538-4357/abfa9d Bibcode: 2021ApJ...914...46G

Gaur, Haritma; Pandey, Ashwani; Mohan, Prashanth

Flat-spectrum radio quasars (FSRQs) are a subclass of blazars characterized by prominent optical emission lines and a collimated large-scale jet along the observer's line of sight. An X-ray spectral flattening has been reported in FSRQs (at relatively high redshifts) that is attributable either to absorption from gas along the line of sight or to …

2021 The Astrophysical Journal
XMM-Newton 2
Synthesis of radioactive elements in novae and supernovae and their use as a diagnostic tool
DOI: 10.1016/j.newar.2020.101606 Bibcode: 2021NewAR..9201606I

Hernanz, M.; Siegert, T.; Vink, J. +5 more

Novae and supernovae play a key role in many fields of Astrophysics and Cosmology. Despite their importance, an accurate description of which objects explode and why and how they explode is still lacking. One of the main characteristics of such explosions is that they are the main suppliers of newly synthesized chemical elements in the Galaxy. Sin…

2021 New Astronomy Reviews
Gaia INTEGRAL 2
Pitch-angle distribution of accelerated electrons in 3D current sheets with magnetic islands
DOI: 10.1051/0004-6361/202039220 Bibcode: 2021A&A...648A..51Z

Zharkova, V.; Xia, Q.


Aims: This research aims to explore variations of electron pitch-angle distributions (PADs) during spacecraft crossing of reconnecting current sheets (RCSs) with magnetic islands. Our results can benchmark the sampled characteristic features with realistic PADs derived from in situ observations.
Methods: Particle motion is simulated in 2…

2021 Astronomy and Astrophysics
Cluster 2
Planetary nebulae with UVIT: A progress report
DOI: 10.1007/s12036-021-09698-3 Bibcode: 2021JApA...42...71R

Rao, N. Kameswara; Sutaria, F.; Murthy, J. +2 more

The spectral region between 1250–3000 Å contains important spectral lines to understand the morphological structures and evolution of planetary nebulae. This is the region sampled by UVIT through various filter bands both in the continuum and in e…

2021 Journal of Astrophysics and Astronomy
eHST 2
Testing the predictions of axisymmetric distribution functions of galactic dark matter with hydrodynamical simulations
DOI: 10.1088/1475-7516/2021/08/031 Bibcode: 2021JCAP...08..031P

Lavalle, Julien; Petač, Mihael; Núñez-Castiñeyra, Arturo +1 more

Signal predictions for galactic dark matter (DM) searches often rely on assumptions regarding the DM phase-space distribution function (DF) in halos. This applies to both particle (e.g. p-wave suppressed or Sommerfeld-enhanced annihilation, scattering off atoms, etc.) and macroscopic DM candidates (e.g. microlensing of primordial black holes). As …

2021 Journal of Cosmology and Astroparticle Physics
Gaia 2
Stellar wind structures in the eclipsing binary system IGR J18027-2016
DOI: 10.1051/0004-6361/202039088 Bibcode: 2021A&A...647A..75F

García, Federico; Fogantini, Federico A.; Chaty, Sylvain +1 more

Context. IGR J18027-2016 is an obscured high-mass X-ray binary formed by a neutron star accreting from the wind of a supergiant companion with a ∼4.57 d orbital period. The source shows an asymmetric eclipse profile that remained stable across several years.
Aims: We aim to investigate the geometrical and physical properties of stellar wind s…

2021 Astronomy and Astrophysics
XMM-Newton 2
Some Features of Solar Proton Events on March 7, 2011, and on February 20, 2014
DOI: 10.1134/S0010952521040067 Bibcode: 2021CosRe..59..250V

Vlasova, N. A.; Kalegaev, V. V.; Tulupov, V. I.

The paper presents the results of studying two solar proton events—on March 7, 2011, and on February 20, 2014—which are associated with solar flares having almost the same power and located at close heliolongitudes, on the western side of the solar disk. The work was done on the basis of the experimental data obtained from the ACE spacecraft and t…

2021 Cosmic Research
SOHO 2