相关论文: Unresolved multiple stars and Galactic clusters' m…
Binary stars are present in all stellar systems, yet their role is far from being fully understood. We investigate the effect of unresolved binaries in the derivation of open clusters' mass by star counts. We start from the luminosity…
The identification of binary stars of different mass ratios in resolved stellar populations is a challenging task. We show how the photometric diagram constructed with the pseudo-colors (H-W2)-W1 vs W2-(BP-K) can be employed to estimate the…
The observable spectrum of an unresolved binary star system is a superposition of two single-star spectra. Even without a detectable velocity offset between the two stellar components, the combined spectrum of a binary system is in general…
In this study, we continue our project to search for unresolved binary and multiple systems in open clusters exploiting the photometric diagram (H-W2)-W1 vs W2-(BP-K) firstly introduced in \citet{Malofeeva+2022}. In particular, here we…
Binary stars play a vital role in astrophysical research, as a good fraction of stars are in binaries. Binary fraction (BF) is known to change with stellar mass in the Galactic field, but such studies in clusters require binary…
This paper is concerned with the spread in apparent magnitudes (or absolute magnitudes) of main-sequence stars in a star cluster. I specifically consider the effect of binary stars in broadening the main sequence. I present analytic and…
The study of young stellar populations has revealed that most stars are in binary or higher order multiple systems. In this study the influence on the stellar initial mass function (IMF) of large quantities of unresolved multiple massive…
This paper introduces a new method to search for unresolved binary stars in open star clusters. The work aims at improving the approach introduced previously, which employs the (H-W2)-W1 versus W2-(BP-K) photometric diagram. This diagram,…
The stellar initial mass function (IMF) high-mass slope $\alpha$ is routinely measured by fitting single-star models to photometric samples that contain 20-90% unresolved binaries. This practice introduces a systematic negative bias on…
We perform spatially-resolved, pixel-by-pixel SED fitting on galaxies up to $z\sim2.5$ in the Hubble Extreme Deep Field (XDF). Comparing stellar mass estimates from spatially resolved and spatially unresolved photometry we find that…
The principal goal of this paper is to specify conditions of detection of unresolved binaries by multicolor photometry. We have developed a method for estimating the critical distance at which an unresolved binary of given mass and age can…
We investigate blending, binarity and photometric biases in crowded-field CCD imaging. For this, we consider random blend losses, which correspond to the total number of stars left undetected in unresolved blends. We present a simple…
Binary stars play a major role in determining the dynamic evolution of star clusters. We used images collected with the Hubble Space Telescope to study fourteen Magellanic Clouds star clusters that span an age interval between $\sim 0.6$…
We develop a general method to "self-calibrate" observations of galaxy clustering with respect to systematics associated with photometric calibration errors. We first point out the danger posed by the multiplicative effect of calibration…
We report about an ongoing photometric and spectroscopic monitoring survey of about 250 O- and 540 B-type stars in the southern Milky Way with the aim to determine the fraction of close binary systems as a function of mass and to determine…
In this paper we explore the effects that the presence of a fraction of binary stars has in the determination of a star cluster mass via the virial theorem. To reach this aim in an accurate and consistent way, we run a set of simulations…
Understanding the multiplicity of stellar systems and the correlations between their hierarchical components provides crucial insights into star formation processes. If binary companions form independently in each component of a wide binary…
I discuss two of the possible sources of biases in the determination of the IMF: binning and the existence of unresolved components. The first source is important for clusters with a small number of stars detected in a given mass bin while…
A technique is described for the detection and measurement of close binary systems whose images are unresolved. The method is based on analysis of the moment of inertia tensor of the image, from which the product of the binary flux ratio…
We introduce a model Galactic field low-mass stellar population that has a proportion of binary systems as observed, with a mass ratio distribution consistent with observational constraints. The model single star and system luminosity…