Related papers: Structure and dynamics of the class I young stella…

Circumstellar disks are expected to form early in the process that leads to the formation of a young star, during the collapse of the dense molecular cloud core. It is currently not well understood at what stage of the collapse the disk is…

This paper examines the density and velocity structure of envelopes around young stellar objects through submillimeter continuum imaging of four objects in Taurus and previously obtained molecular-line data. Observations carried out with…

Evidence for a transitional stage in the formation of a low-mass star is reported, intermediate between the fully embedded and the T Tauri phases. Millimeter aperture synthesis observations in the HCO+ J=1-0 and 3-2, HCN 1-0, 13CO 1-0, and…

A fundamental question about the early evolution of low-mass protostars is when circumstellar disks may form. High angular resolution observations of molecular transitions in the (sub)millimeter wavelength windows make it possible to…

We model Spitzer Space Telescope observations of the Taurus Class 0 protostar L1527 IRS (IRAS 04368+2557) to provide constraints on its protostellar envelope structure. The nearly edge-on inclination of L1527 IRS, coupled with the highly…

The recently discovered protostellar jet known as HH212 is beautifully symmetric, with a series of paired shock knots and bow shocks on either side of the exciting source region, IRAS 05413-0104 (Zinnecker et al. 1998). We present VLA…

We have conducted mapping observations ($\sim 2'\times2'$) of the Class I protostar L1489 IRS using the 7-m array of the Atacama Compact Array (ACA) and the IRAM-30m telescope in the $\mathrm{C^{18}O}$ 2-1 emission to investigate the gas…

We explore the infrared M band (4.7 um) spectrum of the class I protostar L1489 IRS in the Taurus Molecular Cloud. This is the highest resolution wide coverage spectrum at this wavelength of a low mass protostar observed to date (R=25,000;…

We have observed the three low-mass protostars, IRAS 15398$-$3359, L1527 IRS and TMC-1A, with the ALMA 12-m array, the ACA 7-m array, and the IRAM-30m and APEX telescopes in the C$^{18}$O $J=2$-1 emission. Overall, the C$^{18}$O emission…

We conducted IRAM-30m C18O (2-1) and SMA 1.3mm continuum, 12CO (2-1), and C18O (2-1) observations toward the Class 0/I protostar L1455 IRS1 in Perseus. The IRAM results show L1455 IRS1 located in a dense core of 0.05 pc in size with a mass…

Context. The youngest protostars that power energetic outflows are surrounded by infalling and rotating envelopes that contain most of the mass of the system. Aims. To study the properties and kinematics of the protostellar envelope…

We model the Class I source L1551 IRS 5, adopting a flattened infalling envelope surrounding a binary disk system and a circumbinary disk. With our composite model, we calculate self-consistently the spectral energy distribution of each…

We present a detailed millimeter line study of the circumstellar environment of the low-luminosity Class 0 protostar IRAM 04191+1522 in the Taurus molecular cloud. New line observations demonstrate that the ~14000 AU radius protostellar…

Deep Spitzer IRAC images of L1157 reveal many of the details of the outflow and the circumstellar environment of this Class 0 protostar. In IRAC band 4, 8 microns, there is a flattened structure seen in absorption against the background…

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…

We have observed the Class I protostar L1489 IRS with the Atacama Millimeter/submillimeter Array (ALMA) in Band 6. The C$^{18}$O $J=$2-1 line emission shows flattened and non-axisymmetric structures in the same direction as its velocity…

Recent observations of the Class 0 protostar L1527 IRS have revealed a rotationally supported disc with an outer radius of at least 100 au. Measurements of the integrated flux at 870 microns suggest a disc mass that is too low for…

Constraining the physical and chemical structure of young embedded disks is crucial to understanding the earliest stages of planet formation. As part of the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter…

Precise estimates of protostellar masses are crucial to characterize the formation of stars of low masses down to brown-dwarfs (BDs; M* < 0.08 Msun). The most accurate estimation of protostellar mass uses the Keplerian rotation in the…

A fundamental part of the study of star formation is to place young stellar objects in an evolutionary sequence. Establishing a robust evolutionary classification scheme allows us not only to understand how the Sun was born but also to…