Astronomy – Page 2 – Tech Creative Commons

MPI-AMRVAC 3.0: Updates to an open-source simulation framework

By admin / December 14, 2023

R. Keppens1, B. Popescu Braileanu1, Y. Zhou1, W. Ruan1, C. Xia2, Y. Guo3, N. Claes1 and F. Bacchini1,4 + Received: 2 November 2022 Accepted: 12 March 2023 Abstract Context. Computational astrophysics nowadays...

MPI-AMRVAC 3.0: Updates to an open-source simulation framework

A physical model for the magnetosphere of Uranus at solstice time (Pantellini)

By admin / November 30, 2023

by Filippo Pantellini 2020. The magnetosphere of Uranus is subject to strong seasonal variations. The variability is a consequence of...

A physical model for the magnetosphere of Uranus at solstice time (Pantellini)

Optical levitation-associated atomic loading in a dipole trap

By admin / November 9, 2023

We demonstrate a robust method for the efficient optically levitated loading of ultracold Cs atoms in a crossed dipole trap. When preparing a large number of atomic samples, a large-volume crossed dipole trap is required to form a shallow but very efficient loading potential.

Optical levitation-associated atomic loading in a dipole trap

Roadmap on all-optical processing

By admin / October 9, 2023

The ability to process optical signals without passing into the electrical domain has always attracted the attention of the research community. Processing photons by photons unfolds new scenarios, in principle allowing for unseen signal processing and computing capabilities.

Mean Estimate Distances for Galaxies with Multiple Estimates in NED-D

By admin / August 11, 2023

Numerous research topics rely on an improved cosmic distance scale (e.g., cosmology, gravitational waves) and the NASA/IPAC Extragalactic Database of Distances (NED-D) supports those efforts by tabulating multiple redshift-independent distances for 12,000 galaxies (e.g., Large Magellanic Cloud (LMC) zero-point). Six methods for securing a mean estimate distance (MED) from the data are presented (e.g., indicator and Decision Tree).

Mean Estimate Distances for Galaxies with Multiple Estimates in NED-D

Self-consistent Color–Stellar Mass-to-light Ratio Relations for Low Surface Brightness Galaxies

By admin / May 23, 2023

The color–stellar mass-to-light ratio relation (CMLR) is a widely accepted tool for estimating the stellar mass (M *) of a galaxy. However, an individual CMLR tends to give distinct M * for a same galaxy when it is applied in different bands. Examining five representative CMLRs from the literature, we find that the difference in M * predicted in different bands from optical to near-infrared by a CMLR is 0.1 ~ 0.3 dex.

Self-consistent Color–Stellar Mass-to-light Ratio Relations for Low Surface Brightness Galaxies

Linking gravitational waves and X-ray phenomena with joint LISA and Athena observations

By admin / March 13, 2023

The evolution of cosmic structures, the formation and growth of the first black holes and the connection to their baryonic environment are key unsolved problems in astrophysics. The X-ray Athena mission and the gravitational-wave Laser Interferometer Space Antenna (LISA) offer independent and complementary angles on these problems.

Linking gravitational waves and X-ray phenomena with joint LISA and Athena observations

Upper limits for PH3 in the atmosphere of Mars

By admin / May 2, 2021

Phosphine (PH3) is proposed to be a possible biomarker in planetary atmospheres and has been claimed to have been observed in the atmosphere of Venus, sparking interest in the habitability of Venus’s atmosphere. Observations of another biomarker, methane (CH4), have been reported several times in the atmosphere of Mars, hinting at the possibility of a past or present biosphere.

Upper limits for PH3 in the atmosphere of Mars

Two distinctive regimes in the charge transport of a magnetic topological ultra thin film

By admin / February 10, 2021

The effect of the magnetic impurities on the charge transport in a magnetic topological ultra-thin film (MTF) is analytically investigated by applying the semi-classical Boltzmann framework through a modified relaxation-time approximation.

Two distinctive regimes in the charge transport of a magnetic topological ultra thin film

Fundamental mode intensity evolution in tapered optical fibres

By admin / December 9, 2020

The mode field intensity, spot size, central peak intensity evolution and adiabaticity are calculated for different points along the transition of an optical fibre taper that adiabatically tapers from the standard 125 nm down to 1 µm and then to 440 nm diameter for low loss operation at 1550 nm wavelength.

Fundamental mode intensity evolution in tapered optical fibres

Upper limits for PH3 in the atmosphere of Mars

May 2, 2021 admin 0

Exoplanet Sciences with Nulling Interferometers and a Single-mode Fiber-fed Spectrograph

September 6, 2020 admin 0

Understanding the atmospheres of exoplanets is a milestone to decipher their formation history and potential habitability. High-contrast imaging and spectroscopy of exoplanets is the major pathway toward the goal. Direct imaging of an exoplanet requires high spatial resolution.