相关论文: Measuring the Balmer Jump and Effective Gravity in…

Many dark matter (DM) models that are consistent with current cosmological data show differences in the predicted (sub)halo mass function, especially at sub-galactic scales, where observations are challenging due to the inefficiency of star…

This paper describes the design principles for a CCD-based photometric system that is highly optimized for ground-based measurement of the size of the Balmer jump in stellar energy distributions. It is shown that, among ultraviolet filters…

While the direct detection of the dark-matter particle remains very challenging, the nature of dark matter could be possibly constrained by comparing the observed abundance and properties of small-scale sub-galactic mass structures with…

To evaluate a potential usually one analyzes trajectories of test particles. For the Galactic Center case astronomers use bright stars or photons, so there are two basic observational techniques to investigate a gravitational potential,…

Large Galactic stellar surveys and new generations of stellar atmosphere models and spectral line formation computations need to be subjected to careful calibration and validation and to benchmark tests. We focus on cool stars and aim at…

We describe techniques for measuring the central masses of galaxies using emission-line kinematics observed with the Hubble Space Telescope. For accurate results, it is necessary to model various instrumental effects, particularly the…

Cosmic photons can be efficiently collected by broadband intensity mapping but information on their emission redshift and frequency is largely lost. We introduce a technique to statistically recover these otherwise collapsed dimensions by…

GRBs vary more rapidly than any other known cosmological phenomena. The lower limits of this variability have not yet been explored. Improvements in detectors would reveal or limit the actual rate of short GRBs. Were microsecond "spike"…

Balmer lines are an important diagnostic of stellar atmospheric structure, since they are formed at a wide range of depths within the atmosphere. The different Balmer lines are formed at slightly different depths making them useful…

In Bastien et al. (2013) we found that high quality light curves, such as those obtained by Kepler, may be used to measure stellar surface gravity via granulation-driven light curve "flicker". Here, we update and extend the relation…

Chemical analyses of late-type stars are usually carried out following the classical recipe: LTE line formation and homogeneous, plane-parallel, flux-constant, and LTE model atmospheres. We review different results in the literature that…

We report on a high precision measurement of gravitational acceleration using ultracold strontium atoms trapped in a vertical optical lattice. Using amplitude modulation of the lattice intensity, an uncertainty $\Delta g /g \approx 10^{-7}$…

Although the use of RGB photometry has exploded in the last decades due to the advent of high-quality and inexpensive digital cameras equipped with Bayer-like color filter systems, there is surprisingly no catalogue of bright stars that can…

The rapid accumulation of observed Fast Radio Bursts (FRBs) originating from cosmological distances makes it likely that some will be strongly lensed by intervening matter along the line of sight. Detection of lensed FRB repeaters, which…

The measurement of stellar properties such as chemical compositions, masses and ages, through stellar spectra, is a fundamental problem in astrophysics. Progress in the understanding, calculation and measurement of atomic properties and…

We discuss possible tests of the constancy of the velocity of light using distant astrophysical sources such as gamma-ray bursters (GRBs), Active Galactic Nuclei (AGNs) and pulsars. This speculative quest may be motivated by some models of…

Gamma-ray Bursts (GRBs) are the most powerful explosions known, capable of outshining the rest of gamma-ray sky during their short-lived prompt emission. Their cosmological nature makes them the best tool to explore the final stages in the…

We study the capability of the UBVRI photometric system to quantify star clusters in terms of age, metallicity, and color excess by their integrated photometry. The well known age-metallicity-extinction degeneracy was analyzed for various…

We have developed a method to estimate surface gravity (log g) from light curves by measuring the granulation background, similar to the "flicker" method by Bastien et al. (2016) but working in the Fourier power spectrum. We calibrated the…

Astrometric weak gravitational lensing is a powerful probe of the distribution of matter on sub-Galactic scales, which harbor important information about the fundamental nature of dark matter. We propose a novel method that utilizes angular…