Related papers: Testing Theoretical Evolutionary Models with AB Do…

Using the Oxford Short Wavelength Integral Field specTrograph (SWIFT), we investigate radial variations of several initial mass function (IMF) dependent absorption features in M31 and M32. We obtain high signal-to-noise spectra at six…

After decades of brown dwarf discovery and follow-up, we can now infer the functional form of the mass distribution within 20 parsecs, which serves as a constraint on star formation theory at the lowest masses. Unlike objects on the main…

Using a large sample of optical spectra of late-type dwarfs, we identify a subset of late-M through L field dwarfs that, because of the presence of low-gravity features in their spectra, are believed to be unusually young. From a combined…

We provide a new view on the Cygnus-X north complex by accessing for the first time the low mass content of young stellar populations in the region. CFHT/WIRCam camera was used to perform a deep near-IR survey of this complex, sampling…

Recent studies of early-type galaxies have suggested that the initial mass function (IMF) slope is bottom-heavy, i.e. they contain a larger fraction of low-mass stars than the Milky Way. However, measurements of the IMF remain challenging…

We present Spitzer IRAC photometry of twelve very late-type T dwarfs; nine have [3.6], [4.5], [5.8] and [8.0] photometry and three have [3.6] and [4.5] photometry only. We investigate trends with type and color for the planning and…

We present the substellar mass function of star-forming clusters ($\simeq$0.1 Myr old) in a low-metallicity environment ($\simeq$$-$0.7 dex). We performed deep JWST/NIRCam and MIRI imaging of two star-forming clusters in Digel Cloud 2, a…

By combining deep optical imaging and infrared spectroscopy with data from the Two-Micron All-Sky Survey (2MASS) and from previous studies (e.g., Briceno et al.), I have measured the Initial Mass Function (IMF) for a reddening-limited…

We have been using Keck laser guide star adaptive optics to monitor the orbits of ultracool binaries, providing dynamical masses at lower luminosities and temperatures than previously available and enabling strong tests of theoretical…

We present wide-field near-infrared (JHK) images of the young, 2 Myr IC 348 cluster taken with FLAMINGOS. We use these new data to construct an infrared census of sources, which is sensitive enough to detect a 10 Mjup brown dwarf seen…

A recent model for the stellar initial mass function (IMF), in which the stellar masses are randomly sampled down to the thermal Jeans mass from hierarchically structured pre-stellar clouds, predicts that regions of ultra-cold CO gas, such…

A method is presented here for investigating variations in the upper end of the stellar Initial Mass Function (IMF) by probing the production rate of ionizing photons in unresolved, compact star clusters with ages<10 Myr and covering a…

We present deep high dynamic range infrared images of young nearby stars in the Tucana/Horologium and beta Pic associations, all ~ 10 to 35 Myrs young and at ~10 to 60 pc distance. Such young nearby stars are well-suited for direct imaging…

Some M-dwarfs around F-/G-type stars have been measured to be hotter and larger than predicted by stellar evolution models. Inconsistencies between observations and models need addressing with more mass, radius and luminosity measurements…

The complexity of constraining the stellar initial mass function (IMF) in early-type galaxies cannot be overstated, given the necessity of both very high signal-to-noise (S/N) data and the difficulty of breaking the strong degeneracies that…

With a uniform VLT SINFONI data set of nine targets, we have developed an empirical grid of J,H,K spectra of the atmospheres of objects estimated to have very low substellar masses of \sim5-20 MJup and young ages of \sim1-50 Myr. Most of…

We exploit the ability of the Hubble Space Telescope to probe near infrared water absorption present in the atmosphere of low-mass stars, brown dwarfs and planetary mass objects to create a very pure sample of Orion Nebula Cluster (ONC)…

We explore the stellar initial mass function (IMF) of a sample of 49 massive quiescent galaxies (MQGs) at 0.9$<$z$<$1.5. We base our analysis on intermediate resolution spectro-photometric data in the GOODS-N field taken in the…

The Core Mass Functions (CMFs) of low-mass star-forming regions are found to resemble the shape of the Initial Mass Function (IMF). A similar result is observed for the dust clumps in high-mass star forming regions, although at spatial…

A search for young substellar objects in the rho Oph cloud core region has been made using the deep-integration Combined Calibration Scan images of the 2MASS extended mission in J, H and Ks bands, and Spitzer IRAC images at 3.6, 4.5, 5.8…