Astrophysics and Space Science

https://link.springer.com/journal/10509

List of Papers (Total 249)

Making waves in massive star asteroseismology

Massive stars play a major role not only in stellar evolution but also galactic evolution theory. This is because of their dynamical interaction with binary companions, but also because their strong winds and explosive deaths as supernovae provide chemical, radiative and kinematic feedback to their environments. Yet this feedback strongly depends on the physics of the supernova...

Variable stars in the field of the Galactic bulge globular cluster NGC 6522

We present a comprehensive analysis of the variable stars projected on the field of the Galactic bulge globular cluster NGC 6522, offering valuable insights into their characteristics. Using proper motions from Gaia-DR3, we aim to distinguish between field stars and true cluster members. For an accurate color-magnitude diagram of the member stars, we produced a differential...

A hydrogenated amorphous silicon detector for Space Weather applications

The characteristics of a hydrogenated amorphous silicon (a-Si:H) detector are presented here for monitoring in space solar flares and the evolution of strong to extreme energetic proton events. The importance and the feasibility to extend the proton measurements up to hundreds of MeV is evaluated. The a-Si:H presents an excellent radiation hardness and finds application in harsh...

Face-on map of the molecular disc and 3-kpc expanding ring of the galaxy based on a high-accuracy rotation curve

We analyze the longitude-velocity diagram (LVD) of 12CO-line emission from archival data and use the most accurate rotation curve (RC) of the Milky Way to transform radial velocity to face-on position in the galactic plane. We point out that the face-on transformation is highly sensitive to the adopted RC, especially in the inner Milky Way, in the sense that deviations of the RC...

Energetic ion enhancements in sheaths driven by interplanetary coronal mass ejections

We analyze here an energetic proton enhancement in a sheath ahead of a slow interplanetry coronal mass ejection (ICME) detected by Parker Solar Probe on June 30, 2021 at the heliospheric distance of 0.76 AU. The shock was likely quasi-parallel and had a high Mach number. However, the proton fluxes were not enhanced at the shock but about an hour later. The fluxes stayed elevated...

Analysis of photospheric magnetic fields in AR 12546: a case study

We investigate high-resolution observations with the spectropolarimeter (SP) aboard the Hinode satellite of the Solar Optical Telescope (SOT) of a positive polarity sunspot of an active region (AR) (NOAA 12546). We present a case study for the properties of the thermal, magnetic field, and plasma flows as a function of the optical depth from the inversion of the observed Stokes...

Fabry-Pérot etalons in solar astronomy. A review

During the last decades, the use of Fabry-Pérot etalons as filtergraphs has become frequent in solar instruments. The main reason is that they stand out for offering quasi-monochromatic, two-dimensional fields of view much higher than those provided by conventional slit-based spectrographs in a given time interval. Unfortunately, they also present several drawbacks. The number of...

Long-term perturbations in four-body systems with mutual highly inclined orbits

Hierarchical Three Body systems with mutual highly inclined orbits have been well-known since the 1960s. Lidov-Kozai cycles arise within them where the inner orbit eccentricity acquires extreme values. In particular, we focus our research on the motion of exoplanets and exomoons on different Three Body stellar scenarios. Our goal is to study how the LK cycles are perturbed by a...

The Positron Puzzle

The Positron Puzzle is a half-century old conundrum about the origin of the Galactic $\gamma $ -ray emission line at photon energies of 511 keV, and the shape of its morphology, showing a bulge-to-disk luminosity ratio of $\sim 1$ – unlike any astrophysical source distribution. Positrons ( $\mathrm {e}^{+}\mathrm {s}$ ) that have been cooled to the eV scale capture electrons...

Ionospheric single crest events at different altitudes and activity levels observed by Swarm constellation

The current work makes use of eight years of electron density data observed by the Swarm constellation to study the characteristics of the equatorial ionospheric single crest phenomenon recorded at the altitudes of these satellites. The features of single crests have been investigated at different altitudes and geomagnetic activity levels. Results showed that the occurrence rate...

Revealing the atmospheres of highly irradiated exoplanets: from ultra-hot Jupiters to rocky worlds

Spectroscopy of transiting exoplanets has revealed a wealth of information about their atmospheric compositions and thermal structures. In particular, studies of highly irradiated exoplanets at temperatures much higher than those found in our solar system have provided detailed information on planetary chemistry and physics because of the high level of precision which can be...

A standalone prediction model for atomic oxygen and coronal mass ejections

This paper presents a standalone predictive model for Atomic Oxygen (AO), Coronal Mass Ejections (CMEs) and other space-environment parameters. The prediction is based on the numerical method of Holt–Winter’s triple smooth exponential forecasting of atmospheric constituents. Solar cycle 25 is likely to show about the same activity as cycle 23. The corresponding AO-flux–solar...

The origin of free-floating planets

Free-floating planets (FFPs) are the lightest products of star formation and they carry important information on the initial conditions of the environment in which they were formed. They were first discovered in the 2000 s but still few of them have been identified and confirmed due to observational challenges. This is a review of the last advances in the detection of these...

Radio and mid-infrared properties of the blazar J1419–0838

The radio quasar NVSS J141922−083830 (J1419−0838) was initially classified as an uncategorised blazar-type object, following its detection in the $\gamma $ -ray band with the Fermi space telescope. Later, using multi-waveband observations and modeling, its was found to be a flat-spectrum radio quasar (FSRQ). However, its radio emission has never been discussed in depth in the...

Accretion disks, quasars and cosmology: meandering towards understanding

As Setti and Woltjer noted back in 1973, one can use quasars to construct the Hubble diagram; however, the actual application of the idea was not that straightforward. It took years to implement the proposition successfully. Most ways to employ quasars for cosmology now require an advanced understanding of their structure, step by step. We briefly review this progress, with...

Hints of the photometric period in radial velocity data of the X-ray binary HD 3191 with the Joan Oró telescope

We focus our attention on the newly proposed X-ray binary system HD 3191 whose nature still lacks dynamical confirmation and accurate orbital parameters. The positional agreement of this object with a flaring gamma-ray source was the original motivation of this work, although the present chances of association are reduced. A long-term spectroscopic monitoring of HD3191 was...

Hydrogen Lyman-Alpha Periodicity Behaviour During Various Solar Cycles

The temporal behaviour of various periodicities of hydrogen Lyman-alpha (Ly- $\alpha $ ) between 1950 and 2020 have been analysed using Lomb-Scargle and Morlet wavelets spectral analysis techniques. Daily mean values of Ly- $\alpha $ radiance ( https://lasp.colorado.edu/lisird/data/composite_lyman_alpha/ ) for each individual year were used in this investigation to obtain the...

Testing time evolution of mass distribution of black hole mergers

The detection of gravitational-wave events revealed that there are numerous populations of black hole (BH) binaries that can merge within the age of the Universe. Although several formation channels of such binaries are known, considerable theoretical uncertainties associated with each channel defeat the robust prediction of how much each channel contributes to the total merger...

Effects of noise on the accuracy of plasma bulk parameters derived from velocity moments of in-situ observations

We expose and quantify the inaccuracies of plasma bulk parameters derived from the calculation of velocity moments of noisy in-situ plasma observations. First, we simulate typical solar wind proton plasma observations, obtained by a typical top-hat electrostatic analyzer instrument. We add background noise to the simulated observations and analyze them by applying standard...