Related papers: A maximum likelihood method for fitting colour-mag…
The relative age of galaxies at different redshifts can be used to infer the Hubble parameter and put constraints on cosmological models. We select 23,883 quiescent luminous red galaxies (LRGs) from the SDSS DR7 and divide them into four…
Determination of stellar age is a crucial task in astrophysics research. Different methods are nowadays used either model dependent or based on calibrated empirical relations. The most reliable results are generally obtained when different…
High spectral resolution evolutionary synthesis models have become a routinely used ingredient in extragalactic work, and as such deserve thorough testing. Star clusters are ideal laboratories for such tests. This paper applies the spectral…
Standard maximum-likelihood estimators for binary-star and exoplanet eccentricities are biased high, in the sense that the estimated eccentricity tends to be larger than the true eccentricity. As with most non-trivial observables, a simple…
We present new isochrone fits to colour-magnitude diagrams of the Galactic globular clusters NGC\,288, NGC\,362, and NGC\,6218 (M12). We utilize a lot of photometric bands from the ultraviolet to mid-infrared by use of data from the {\it…
Recent data from the James Webb Space Telescope allow a first glimpse of galaxies at $z \gtrsim 11$. The most successful tool for identifying ultra-high-redshift candidates and inferring their properties is photometric template fitting.…
Precise stellar ages are fundamental to Galactic archaeology. However, obtaining reliable age estimates and uncertainties for field stars has been a long-standing challenge. We test the fidelity of ages from recent catalogs of giants and…
We present the results of a long term orbit monitoring program, using sparse aperture masking observations taken with NIRC2 on the Keck-II telescope, of seven G to M-type members of the Upper Scorpius subgroup of the Sco-Cen OB association.…
We performed a theoretical investigation focused on the age estimate of RGB stars in OCs based on mixed classical surface and asteroseismic parameters. We evaluated the performances of three widely adopted methods (pure geometrical fit,…
The (rest-frame) near-IR domain contains important stellar population diagnostics and is often used to estimate masses of galaxies at low as well as high redshifts. However, many stellar population models are still relatively poorly…
We present a novel technique for estimating disk parameters (the centre and the radius) from its 2D image. It is based on the maximal likelihood approach utilising both edge pixels coordinates and the image intensity gradients. We emphasise…
We present the underlying relations between colour-magnitude diagrams (CMDs) and synthesis models through the use of stellar luminosity distribution func- tions. CMDs studies make a direct use of the stellar luminosity distribution function…
Variable stars with well-calibrated period-luminosity relationships provide accurate distance measurements to nearby galaxies and are therefore a vital tool for cosmology and astrophysics. While these measurements typically rely on samples…
The next generation near- and mid-infrared Galactic surveys will yield a large number of new highly obscured star clusters. Detailed characterization of these new objects with spectroscopy is time-consuming. Diagnostic tools that will be…
Stellar photometric variability offers a novel probe of the interior structure and evolutionary state of stars. Here we present a census of stellar variability on day to decade timescales across the color-magnitude diagram for 73,000 stars…
The possibility of determining cosmological parameters on the basis of a wide set of observational data including the Abell-ACO cluster power spectrum and mass function, peculiar velocities of galaxies, the distribution of Ly-$\alpha$…
The calibration of the tip of the red giant branch (TRGB) in the $I$-band has a direct role in determinations of the Hubble constant, a subject of recent interest due to the discrepancy between direct and indirect estimates of its value. We…
In this paper we explore a quantitative and efficient method to constrain the halo properties of distant galaxy populations through ``galaxy--galaxy" lensing and show that the mean masses and sizes of halos can be estimated accurately,…
We present a new empirical method for fitting multicolor light curves of Type Ia supernovae. Our method combines elements from two widely used techniques in the literature: the delta_m15 template fitting method and the Multicolor…
We present the new technique for the determination of the low-mass slope of the stellar mass function from the pixel-space fitting of integrated light spectra. This technique is the extension of the NBursts full spectral fitting technique.…