相关论文: Mid-Infrared Observations of Class I/Flat-Spectrum…

We present new near-IR observations of 76 Class I/flat-spectrum objects in the nearby (d < 320 pc) Perseus, Taurus, Chamaeleon I and II, rho Ophiuchi, and Serpens dark clouds. These observations are part of a larger systematic infrared…

We present new near- and mid-infrared observations of 19 Class I/flat-spectrum young stellar objects in the nearby Rho Oph (d=125pc) and Serpens (d=310pc) dark clouds. These observations are part of a larger systematic infrared multiplicity…

We present high resolution (R = 18,000), high signal-to-noise, 2 micron spectra of 52 infrared-selected Class I and flat-spectrum young stellar objects in the Taurus-Auriga, $\rho$ Ophiuchi, Serpens, Perseus, and Corona Australis dark…

(Abridged) We performed a deep infrared imaging survey of 63 embedded young stellar objects (YSOs) located in the Taurus and Ophiuchus clouds to search for companions. The sample includes Class I and flat infrared spectrum protostellar…

(abridged) Our project endeavors to obtain a robust view of multiplicity among embedded Class I and Flat Spectrum protostars in a wide array of nearby molecular clouds to disentangle ``universal'' from cloud-dependent processes. We have…

We present optical and near-IR spectroscopy (600--1000 nm) of 8 faint (I$>$18) very red (R--I$>$2.2) objects discovered in a deep CCD survey of the Pleiades (Zapatero-Osorio et al. 1996). We compare them with reliable cluster members like…

We present the results of a search for companions to young brown dwarfs in the Taurus and Chamaeleon I star forming regions (1/2-3 Myr). We have used WFPC2 on board HST to obtain F791W and F850LP images of 47 members of these regions that…

With Herschel/PACS 134 low mass members of the Taurus star-forming region spanning the M4-L0 spectral type range and covering the transition from low mass stars to brown dwarfs were observed. Combining the new Herschel results with other…

We present the results of a near-IR spectroscopic survey of 110 Class I protostars observed from 0.80 microns to 2.43 microns at a spectroscopic resolution of R=1200. We find that Class I objects exhibit a wide range of lines and the…

We present 0.95--2.5 micron moderate (R = 500) resolution spectra of 19 ISOCAM detected sources in the Chamaeleon I dark cloud. Thirteen of these stars are candidate very low mass members of the cloud proposed by Persi et al. (2000 A&A…

Results of a comprehensive, new, ground-based mid-infrared imaging survey of the young stellar population of the Rho Ophiuchi cloud are presented. Data were acquired at the Palomar 5-m and at the Keck 10-m telescopes with the MIRLIN and LWS…

We have analyzed photometric and spectroscopic data of a sample of 14 spatially resolved pre-main-sequence binaries (separations 0.6" to 1.7") in the nearby (150 pc) low-mass star-forming regions of Chamaeleon, Lupus, and rho Ophiuchi. The…

It is now well established that many young brown dwarfs exhibit characteristics similar to classical T Tauri stars, including infrared excess from disks and emission lines related to accretion. Whether the same holds true for even lower…

Far-infrared and (sub)millimeter fluxes can be used to study dust in protoplanetary disks, the building blocks of planets. Here, we combine observations from the Herschel Space Observatory with ancillary data of 284 protoplanetary disks in…

We present new HST/WFPC2 observations of 20 fields centered around T Tauri stars in the Chamaeleon I star forming region. Images have been obtained in the F631N ([OI]6300A), F656N (Ha) and F673N ([SII]6716A+6731A) narrow-band filters, plus…

We present nuclear spectral energy distributions (SEDs) in the range 0.4-16micron for an expanded CfA sample of Seyfert galaxies. The spectral indices from 1-16micron range from alpha_IR 0.9 to 3.8. The shapes of the spectra are correlated…

We present first results of a survey for companions among X-ray selected pre-main sequence stars, most of them being weak-line T Tauri stars (WTTS). These T Tauri stars have been identified in the course of optical follow-up observations of…

We present optical spectra of eight candidate brown dwarfs and a previously known T Tauri star (Sz 33) of the Chamaeleon I dark cloud. We derived spectral types based on the strength of the TiO or VO absorption bands present in the spectra…

We have combined new I, J, H, and Ks imaging of portions of the Chamaeleon II, Lupus I, and Ophiuchus star-forming clouds with 3.6 to 24 micron imaging from the Spitzer Legacy Program, "From Molecular Clouds to Planet Forming Disks", to…

We present 6300--10100 {\AA} spectra for a sample of 13 T dwarfs observed using LRIS mounted on the Keck I 10m Telescope. A variety of features are identified and analyzed, including pressure-broadened K I and Na I doublets; narrow Cs I and…