相关论文: Constraining the structure of the non-spherical pr…

Large field surveys of NH3, C2S, 13CO and C18O in the L1551 dark cloud have revealed a prolate, pre-protostellar molecular core (L1551-MC) in a relatively quiescent region to the northwest of the well-known IRS 5 source. The kinetic…

Context. The largest grains (0.5-1 micron) in the interstellar size distribution are efficient in scattering near- and mid-infrared radiation. These wavelengths are therefore particularly well suited to probe the still uncertain high-end of…

Using the IRAM 30m telescope, we mapped the methanol emission in the pre-stellar core L1544 and observed singly deuterated methanol (CH$_2$DOH and CH$_3$OD) towards the dust peak of L1544. Non-LTE radiative transfer modelling was performed…

Short version: We apply a new synergetic radiative transfer method: the derived 1D density profiles are both consistent with a cut through the Herschel PACS/SPIRE and JCMT SCUBA-2 continuum maps of L1689B and with a derived local…

Spectral line profiles of several molecules observed towards the pre-stellar core L1544 appear double-peaked. For abundant molecular species this line morphology has been linked to self-absorption. However, the physical process behind the…

In the centre of pre-stellar cores, deuterium fractionation is enhanced due to the low temperatures and high densities. Therefore, the chemistry of deuterated molecules can be used to study the earliest stages of star formation. We analyse…

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…

We have computed the dust temperature distribution to be expected in a pre-protostellar core in the phase prior to the onset of gravitational instability. We have done this in the approximation that the heating of the dust grains is solely…

Context: The $^{15}$N fractionation has been observed to show large variations among astrophysical sources, depending both on the type of target and on the molecular tracer used. These variations cannot be reproduced by the current chemical…

We present 1D radiative transfer modelling of the envelopes of a sample of 18 low-mass protostars and pre-stellar cores with the aim of setting up realistic physical models, for use in a chemical description of the sources. The density and…

We observed the pre-stellar core L1521F in dust emission at 1.2mm and in two transitions each of N2H+, N2D+, C18O, and C17O in order to increase the sample of well studied centrally concentrated and chemically evolved starless cores, likely…

We present an observational study of the protostellar core B335 harboring a low-mass Class 0 source. The observations of the H13CO+(J=1-0) line emission were carried out using the Nobeyama 45 m telescope and Nobeyama Millimeter Array. Our…

Chandra ACIS-I data of the molecular cloud and HII region complex NGC 6334 were analyzed. The hard X-ray clumps detected with ASCA (Sekimoto et al. 2000) were resolved into 792 point sources. After removing the point sources, an extended…

Prestellar cores are unique laboratories for studies of the chemical and physical conditions preceding star formation. We observed the prestellar core L1544 in the fundamental transition of ortho-H2D+ (1_1,0-1_1,1) at different positions…

Stars like our Sun form in self-gravitating dense and cold structures within interstellar clouds, called pre-stellar cores. Although much is known about the physical structure of dense clouds just before and soon after the switch-on of a…

We have studied the optical, near-IR and radio properties of a complete sample of 43 sources detected at 15-micron in one of the deeper ELAIS repeatedly observed region. The extragalactic objects in this sample have 15-micron flux densities…

Two-dimensional radiative transfer is employed to obtain the broad-band infrared spectrum of active galaxies. In the models we vary the geometry and size of the obscuring medium, the surface density, the opacity and the grain size…

The young massive star-forming region IRAS05358+3543 was observed at high-spatial resolution in the continuum emission at 3.1 and 1.2mm with the Plateau de Bure Interferometer, and at 875 and 438mum with the Submillimeter Array. We resolve…

Using recent dust continuum data, we generate the intrinsic ellipticity distribution of dense, starless molecular cloud cores. Under the hypothesis that the cores are all either oblate or prolate randomly-oriented spheroids, we show that a…

With the Submillimeter Array, the brightest (sub)millimeter continuum source in the OMC-2/3 region, MMS 6, has been observed in the 850 um continuum emission with approximately 10 times better angular resolution than previous studies…