相关论文: Westerlund 1 as a Template for Massive Star Evolut…
In this letter, we reconstruct the formation pathway of MRG-S0851, a massive, $\log M_*/M_\odot=11.02\pm0.04$, strongly lensed, red, galaxy at $z=1.883\pm0.001$. While the global photometry and spatially-resolved outskirts of MRG-S0851…
In the hierarchical structure formation model of the universe, galaxy clusters are assembled through a series of mergers. Accordingly, it is expected that galaxy clusters in the early universe are actively forming and dynamically young.…
Wolf-Rayet stars are evolved massive stars, and the relative number of WC-type and WN-type WRs should vary with the metallicity of the host galaxy, providing a sensitive test of stellar evolutionary theory. However, past studies of the WR…
The goal of this study is to determine a distance to Westerlund 1 independent of the characteristics of the stellar population and to study its neutral environment, using observations of atomic hydrogen. The HI observations are taken from…
The Spitzer Space Telescope is devoting a significant fraction of the observing time to multi-wavelength cosmological surveys of different depths in various low-background sky regions. Several tens of thousand mid-IR galaxies have been…
Several clusters of red supergiants have been discovered in a small region of the Milky Way close to the base of the Scutum-Crux Arm and the tip of the Long Bar. Population synthesis models indicate that they must be very massive to harbour…
Using high-resolution, multiple-passband Hubble Space Telescope images spanning the entire optical/near-infrared wavelength range, we obtained a statistically complete sample, $U$-band selected sample of 846 extended star clusters across…
The young star cluster W3 (age 300-500 Myr) in NGC 7252 is the most luminous star cluster known to date. Dynamical mass estimates result in 8 +/- 2 * 10^7 M_sun. With an effective radius of about 18 pc and a velocity dispersion of 45 km/s…
The K-band Hubble diagram for a sample of brightest cluster galaxies (BCGs) in the redshift range 0<z<1 shows a very small scatter (0.3 magnitudes r.m.s). The BCGs exhibit very little luminosity evolution in this redshift range: if q_0=0.0…
Yellow and red supergiants are evolved massive stars whose numbers and locations on the HR diagram can provide a stringent test for models of massive star evolution. Previous studies have found large discrepancies between the relative…
Galaxies in the Local Group span a factor of 15 in metallicity, ranging from the super-solar M31 to the Wolf-Lundmark-Melotte (WLM) galaxy, which is the lowest-metallicity (0.1xZsun) Local Group galaxy currently forming stars. Studies of…
Massive stars are important for the evolution of the interstellar medium. The detailed study of their properties (such as mass loss, rotation, magnetic fields) is enormously facilitated by samples of these objects in young massive galactic…
By matching infrared-selected, massive young stellar objects (MYSOs) and compact HII regions in the RMS survey to massive clumps found in the submillimetre ATLASGAL survey, we have identified ~1000 embedded young massive stars between…
The Arches is one of the youngest, densest and most massive clusters in the Galaxy. As such it provides a unique insight into the lifecycle of the most massive stars known and the formation and survival of such stellar aggregates in the…
We have identified six early-type galaxies at z>2.8 in the central 5.76 arcmin^2 Hubble Ultra Deep Field NICMOS region based on a pronounced broad-band discontinuity between the NICMOS F110W and F160W bandpasses. These galaxies have red…
We carried out a photometric and structural analysis in the rest-frame $V$ band of a mass-selected ($\log M/M_\odot >10.7$) sample of red-sequence galaxies in 14 galaxy clusters, 6 of which are at $z>1.45$. To this end, we reduced/analyzed…
We examined the morphology-density relations for galaxy samples selected by luminosity and by mass in each of five massive X-ray clusters from z=0.023 to 0.83 for 674 spectroscopically-confirmed members. Rest-frame optical colors and visual…
Stars with masses in excess of 100 Msun are observed in the Local Universe, but they remain rare objects. Because of the shape of the mass function, they are expected to be present only in the most massive and youngest clusters. They may…
We measure the average mass properties of a sample of 41 strong gravitational lenses at moderate redshift (z ~ 0.4 - 0.9), and present the lens redshift for 6 of these galaxies for the first time. Using the techniques of strong and weak…
We investigate Wolf-Rayet (WR) stars as a source of feedback contributing to the removal of natal material in the early evolution of massive star clusters. Despite previous work suggesting that massive star clusters clear out their natal…