相关论文: Nomads of the Galaxy

We examine the possibility that very massive stars greatly exceeding the commonly adopted stellar mass limit of 150 Msun may be present in young star clusters in the local universe. We identify ten candidate clusters, some of which may host…

Substructure in distant gravitational lens galaxies can be detected because it alters the brightnesses and shapes of the lensed images. The optical and radio flux ratios in the four-image lens B1422+231 imply that there is a \sim 10^4-10^7…

The probability of detecting a planetary companion of a lensing star during a microlensing event toward the Galactic center, averaged over all relevant event and galactic parameters, when the planet-star mass ratio $q=0.001$ has a maximum…

We demonstrate that stars beyond the virial radii of galaxies may be generated by the gravitational impulse received by a satellite as it passes through the pericenter of its orbit around its parent. These stars may become energetically…

We describe the structural and kinematic properties of the first compact stellar systems discovered by the AIMSS project. These spectroscopically confirmed objects have sizes ($\sim$6 $<$ R$_{\rm e}$ [pc] $<$ 500) and masses…

Planet frequency shows a strong positive correlation with host mass from the hydrogen-burning limit to M ~ 2Msun. No search has yet been conducted for planets of higher-mass hosts because all existing techniques are insensitive to these…

The relationship between galaxies and dark matter can be characterized by the halo mass of the central galaxy and the fraction of galaxies that are satellites. Here we present observational constraints from the SDSS on these quantities as a…

Paczy\'nski (1986) suggested that ``dark" objects in the halo of our Galaxy could enhance the luminosity of foreground stars, acting as gravitational microlenses. Such events has been recently reported by different collaborations. We assume…

Star-forming clumps have been found to significantly influence the star formation of gas-rich $z>1$ galaxies. Using public data from JWST/NIRCam (COSMOS-Web) and ALMA (FMOS-COSMOS), we study a sample of 32 massive ($>10^{10.5}\,\rm…

It is plausible that most of the Stars in the Milky Way (MW) Galaxy, like the Sun, consist of planetary systems, instead of a single planet. Out of the estimately discovered 3,950 planet-hosting stars, about 860 of them are known to be…

We present an update of results from the search for microlensing towards the Large Magellanic Cloud (LMC) by EROS (Experience de Recherche d'Objets Sombres). We have now monitored 25 million stars over three years. Because of the small…

Stars form in the Galaxy with a wide range in mass. If the mass is below 7% of the Sun's, then the object does not become hot enough for stable hydrogen burning. These substellar objects are called brown dwarfs. Maps of the sky at infrared…

I show that by observing microlensing events both astrometrically and photometrically, the Space Interferometry Mission (SIM) can measure the mass function of stellar remnants in the Galactic bulge including white dwarfs, neutron stars, and…

We investigate the evolution of compact galaxy number density over the redshift range $0.2<z<0.8$. Our sample consists of galaxies with secure spectroscopic redshifts observed in the COSMOS field. With the large uncertainties, the compact…

The Galactic open cluster Westerlund 1 (Wd 1) represents the ideal local template for extragalactic young massive star clusters, because it is currently the only nearby young cluster which reaches a mass of around 10^5 Msun. The proximity…

Stellar mass has been shown to correlate with halo mass, with non-negligible scatter. The stellar mass-size and luminosity-size relationships of galaxies also show significant scatter in galaxy size at fixed stellar mass. It is possible…

Microlensing planets occurring on faint source stars can escape detection due to their weak signals. Occasionally, detections of such planets are not reported due to the difficulty of extracting high-profile scientific issues on the…

The Nancy Grace Roman Space Telescope (Roman) will perform a Galactic Exoplanet Survey (RGES) to discover bound exoplanets with semi-major axes greater than 1 au using gravitational microlensing. Roman will even be sensitive to planetary…

It is firmly established that the stellar mass distribution is smooth, covering the range 0.1-100 Msun. It is to be expected that the masses of the ensuing compact remnants correlate with the masses of their progenitor stars, and thus it is…

Given the frequency of stellar multiplicity in the solar neighborhood, it is important to study the impacts this can have on exoplanet properties and orbital dynamics. There have been numerous imaging survey projects established to detect…