相关论文: Formaldehyde emission from low mass protostars

We present theoretical predictions of the rotational line emission of deuterated water in low-mass protostar collapsing envelopes. The model accounts for the density and temperature structure of the envelope, according the inside-out…

Context. "Snow lines", marking regions where abundant volatiles freeze out onto the surface of dust grains, play an important role for planet growth and bulk composition in protoplanetary disks. They can already be observed in the envelopes…

We present new observations of near-infrared molecular hydrogen (H2) line emission in a sample of 18 Class I and flat-spectrum low mass protostars, primarily in the Tau- Aur and {\rho} Oph dark clouds. The line emission is extended by up to…

We present new results on CO depletion in a sample of nearby pre-stellar cores, based on observations of the millimeter C17O and C18O lines and the 1.3 mm dust emission with the IRAM 30m telescope. In most cases, the distribution of CO is…

We are studying the extremely young cluster of M17 to investigate the birth of high-mass stars and the initial mass function. Deep JHKL imaging and K-band spectroscopy from the VLT of 201 stars toward the cluster is presented. The majority…

We have tested some relations for star formation rates used in extra-galactic studies for regions within the Galaxy. In nearby molecular clouds, where the IMF is not fully-sampled, the dust emission at 24 micron greatly underestimates star…

Accurate techniques which allow for the derivation of the spatial density in star formation regions are rare. A technique which has found application for the derivation of spatial densities in Galactic star formation regions utilizes the…

We investigate the bright CO fundamental emission in the central regions of five protostars in their primary mass assembly phase using new observations from JWST's Near-Infrared Spectrograph (NIRSpec) and Mid-Infrared Instrument (MIRI). CO…

With the Infrared Space Observatory, we conducted 3x3-pixel imaging photometry of twelve luminosity class III stars, which were previously presumed to have dust particles around them, at far infrared wavelengths (60 and 90 um). Eleven out…

We have used deep near-infrared observations with adaptive optics to discover a distributed population of low-mass protostars within the filamentary Infrared Dark Cloud G34.43+00.24. We use maps of dust emission at multiple wavelengths to…

Recent interferometric surveys of nearby main-sequence stars show a faint but significant near-infrared excess in roughly two dozen systems, i.$\,$e. around $10\,\%$ to $30\,\%$ of stars surveyed. This excess is attributed to dust located…

The millimeter-wave rotational emission lines (4(04)-3(03) and 5(05)-4(04)) of protonated carbon dioxide, HCO2+(HOCO+), has been detected toward the low-mass class 0 protostar IRAS 04368+2557 in L1527 with the IRAM 30 m telescope. This is…

We investigate the nature of 24micron sources in M33 which have weak or no associated Halpha emission. Both bright evolved stars and embedded star forming regions are visible as compact infrared sources in the 8 and 24micron maps of M33 and…

Intriguing work on observations of 4.83 GHz formaldehyde (H2CO) absorptions and 4.87 GHz H110a radio recombination lines (RRLs) towards 6.7 GHz methanol (CH3OH) maser sources is presented. Methanol masers provide ideal sites to probe the…

We present near-infrared K-band spectra for a sample of 7 Class 0 protostars in the Perseus and Orion star-forming regions. We detect Br gamma, CO overtone, and H2 emission, features that probe the near circumstellar environment of the…

(Abridged) Far-infrared Herschel-PACS spectra of 18 low-mass protostars of various luminosities and evolutionary stages are studied. We quantify their far-infrared line emission and the contribution of different atomic and molecular species…

Maps of the 450 micron and 850 micron dust continuum emission from three star-forming condensations within the Lynds 1630 molecular cloud, made with the SCUBA bolometer array, reveal the presence of four new submillimetre sources, each of a…

At the onset of high-mass star formation, accreting protostars are deeply embedded in massive cores made of gas and dust. Their spectral energy distribution is still dominated by the cold dust and rises steeply from near-to far-infrared…

A population of unidentified gamma-ray sources is forming a structure resembling a halo around the Galactic center. These sources are highly variable, and hence they should be associated with compact objects. Microquasars are objects…

The formation and evolution of young low mass stars are characterized by important processes of mass loss and accretion ocurring in the innermost regions of their placentary circumstellar disks. Because of the large obscuration of these…