We present mid-infrared (10.4, 11.7, and 18.3 m) imaging intended to locate and characterize the suspected protostellar components within the Bok globule CB54. We detect and confirm the protostellar status for the nearinfrared source CB54YC1-II. The mid-infrared luminosity for CB54YC1-II was found to be Lmidir 8 L , and we estimate a central source mass ofM 0:8M (for a mass accretion rate of Ṁ ...

As part of the science demonstration phase of the Herschel mission of the Gould Belt key program, the Aquila rift molecular complex has been observed. The complete ∼3.3◦ × 3.3◦ imaging with SPIRE 250/350/500 μm and PACS 70/160 μm allows a deep investigation of embedded protostellar phases, probing of the dust emission from warm inner regions at 70 and 160 μm to the bulk of the cold envelopes be...

Abstract Massive close binary stars with extremely small separations have been observed, and they are possible progenitors of gravitational-wave sources. The evolution massive binaries in the protostellar accretion stage is key to understanding their formation process. We, therefore, investigate how protostars, consisting a high-density core vast low-density envelope, can approach each other bu...

Abstract Understanding the chemical past of our Sun and how life appeared on Earth is no mean feat. The best strategy we can adopt to study newborn stars located in an environment similar one which was born assess their content. In particular, hot corinos are prime targets because recent studies have shown correlations between interstellar complex organic molecules abundances from comets. ORion...

We present VLT-ISAAC L-band spectroscopy toward 10 stars in SVS 4, a 30 ′′ × 45 ′′ dense cluster of pre-main sequence stars deeply embedded in the Serpens star forming cloud. The ISAAC spectra are combined with archival imaging from UKIRT and ISOCAM to derive accurate extinctions toward the SVS 4 stars. The data are then used to construct a spatial map of the distribution of ice in front of the...

We present a study of the stellar and circumstellar properties of Class I sources using low-resolution (R∼1000) near-infrared Kand L-band spectroscopy. We measure prominent spectral lines and features in 8 objects and use fits to standard star spectra to determine spectral types, visual extinctions, K-band excesses, and water ice optical depths. Four of the seven systems studied are close binar...

Context. Although most young massive stars appear to be part of multiple systems, it is poorly understood how this multiplicity influences the formation of massive stars. The high-mass star-forming region W3 IRS5 is a prime example of a young massive cluster where the cluster center is resolved into multiple subsources at cm and infrared wavelengths, a potential proto-Trapezium system. Aims. We...

Recent models of the envelopes of seven massive protostars are used to analyze observations of H3 infrared absorption and H13CO+ submillimeter emission lines toward these stars, and to constrain the cosmic-ray ionization rate ζCR. The H13CO+ gives best-fit values of ζCR= (2.6 ± 1.8) × 10−17 s−1, in good agreement with diffuse cloud models and with recent Voyager/Pioneer data but factors of up t...

We study the association between embedded star clusters and young stellar objects believed to be precursors of intermediate mass stars (2 <∼ M <∼ 10 M ), within the Vela Molecular Ridge D-cloud. A sample of 12 IRAS-selected Class I sources belonging to the region was imaged in the near infrared bands JHK and the photometry used in order to gain information on the stellar population around these...