相关论文: Spectroscopic substellar initial mass function of …

We studied the properties of the young stellar populations in the NGC 299 cluster in the Small Magellanic Cloud using observations obtained with the Hubble Space Telescope in the $V, I$, and $H\alpha$ bands. We identified 250 stars with…

The strength of gravity-sensitive absorption lines in the integrated light of old stellar populations is one of the few direct probes of the stellar initial mass function (IMF) outside of the Milky Way. Owing to the advent of fully depleted…

Whilst there is a generally accepted evolutionary scheme for the formation of low-mass stars, the analogous processes when moving down in mass to the brown dwarfs regime are not yet well understood. In this first paper we try to build the…

By collecting optical and infrared photometry and low resolution spectroscopy, we have identified a large number of low mass stars and brown dwarf candidates belonging to the young cluster (~5 Myr) associated with the binary star lambda…

It is well known that massive O-stars are frequently (if not always) found in binary or higher-order multiple systems, but this fact has been less robustly investigated for the lower mass range of the massive stars, represented by the…

We present the results of the first broadband 10.8 um survey of the NGC 2024 cluster. The mid-infrared data were combined with our previously published JHKL photometry in order to construct spectral energy distributions for all detected…

We present robust statistical estimates of the accuracy of early-type galaxy stellar masses derived from spectral energy distribution (SED) fitting as functions of various empirical and theoretical assumptions. Using large samples…

Prior to the detection of black holes (BHs) via the gravitational waves (GWs) they generate at merger, the presence of BHs was inferred in X-ray binaries, mostly via dynamical measurements, with masses in the range between $\sim…

Young open clusters are ideal laboratories to understand star formation process. We present deep UBV I and Halpha photometry for the young open cluster IC 1590 in the center of the H II region NGC 281. Early-type members are selected from…

The mass of unresolved young star clusters derived from spectro-photometric data may well be off by a factor of 2 or more once the migration of massive stars driven by mass segregation is accounted for. We quantify this effect for a large…

SONYC -- Substellar Objects in Nearby Young Clusters -- is a program to investigate the frequency and properties of young substellar objects with masses down to a few times that of Jupiter. Here we present a census of very low mass objects…

We present a preliminary analysis of the stellar populations in the central parsecs of a sample of 22 Seyfert 2 galaxies, based on a careful separation of nebular emission and stellar light in high-spatial resolution HST-STIS spectra. 10%…

NGC2264 is a young cluster with a rich circumstellar disk population which makes it an ideal target for studying the evolution of stellar clusters. Our goal is to study its star formation history and to analyse the primordial disk evolution…

Cygnus OB2 is the nearest example of a massive star forming region, containing over 50 O-type stars and hundreds of B-type stars. We have analyzed two Chandra pointings in Cyg OB2, detecting ~1700 X-ray sources, of which ~1450 are thought…

We present deep optical and near-infrared imaging of the rich cluster A2218 at z=0.17. Our optical imaging comes from new multicolour Hubble Space Telescope WFPC2 observations in the F450W (B), F606W (V) and F814W (I) passbands. These…

We demonstrate the feasibility of detecting directly low mass stars in unresolved super-star clusters with ages < 10 Myr using near-infrared spectroscopy at modest resolution (R ~ 1000). Such measurements could constrain the ratio of high…

We have studied the stellar main sequence (MS) of the globular cluster NGC2298 using deep HST/ACS observations in the F606W and F814W bands covering an area of 3.4' x 3.4' around the cluster centre or about twice the cluster's half-mass…

We report here CCD $I$-band time-series photometry of a young (2$-$5 Myr) cluster NGC 2282 to identify and understand the variability of pre-main-sequence (PMS) stars. The $I$-band photometry, down to $\sim$ 20.5 mag, enables us to probe…

We study the disk and accretion properties of young stars in the NGC 2068 and NGC 2071 clusters. Using low-resolution optical spectra, we define a membership sample and determine an age for the region of ~2 Myr. Using high-resolution…

We have used the Gemini Near-infrared Integral Field Spectrograph (NIFS) to map the age distribution of the stellar population in the inner 400 pc of the Seyfert 2 galaxy Mrk 1157 (NGC 591), at a spatial resolution of 35 pc. We have…