Warm gas in protostellar outflows

Gómez-Ruiz, Arturo I.; Wyrowski, F.; Leurini, S.; Menten, K. M.; Güsten, R.

doi:10.1051/0004-6361/201218824

Cited by 13 publications

(14 citation statements)

References 42 publications

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“…Finally, the outflow force in L1448 has been measured by different authors adopting different data and methods. In particular, the value originally measured with single-dish, low-J lineobservations (Bachiller et al 1990)has been confirmed with the analysis of high-resolution interferometric (Hirano et al 2010) and high-J CO (Gomez-Ruiz et al 2013;Y÷ld÷z et al 2014) observations. It is therefore unlikely that all those determinations are overestimated by a factor of 10.…”

Section: Discussionsupporting

confidence: 53%

[O I] 63μm JETS IN CLASS 0 SOURCES DETECTED BYHERSCHEL

Nisini

Santangelo

Giannini

et al. 2015

ApJ

126

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We present Herschel PACS mapping observations of the [O I] 63 μm line toward protostellar outflows in the L1448, NGC 1333-IRAS4, HH 46, BHR 71, and VLA 1623 star-forming regions. We detect emission spatially resolved along the outflow direction, which can be associated with a low-excitation atomic jet. In the L1448-C, HH 46 IRS, and BHR 71 IRS1 outflows this emission is kinematically resolved into blue-and redshifted jet lobes, having radial velocities up to 200 km s −1 . In the L1448-C atomic jet the velocity increases with the distance from the protostar, similarly to what is observed in the SiO jet associated with this source. This suggests that [O I] and molecular gas are kinematically connected and that thelatter could represent the colder cocoon of a jet at higher excitation. Mass flux rates (Ṁ jet (O I)) have been measured from the [O I] 63 μm luminosity adopting two independent methods. We find values in the range (1-4) × 10 −7  M yr −1 for all sources except HH 46, for which an order of magnitude higher value is estimated. Ṁ jet (O I) are compared with mass accretion rates (Ṁ acc ) onto the protostar and with Ṁ jet derived from ground-based CO observations. Ṁ jet (O I)/Ṁ acc ratios are in the range 0.05-0.5, similar to the values for more evolved sources. Ṁ jet (O I) in HH 46 IRS and IRAS4A are comparable to Ṁ jet (CO), while those of the remaining sources are significantly lower than the corresponding Ṁ jet (CO). We speculate that for these three sources most of the mass flux is carried out by a molecular jet, while the warm atomic gas does not significantly contribute to the dynamics of the system.

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Section: Discussionsupporting

confidence: 53%

[O I] 63μm JETS IN CLASS 0 SOURCES DETECTED BYHERSCHEL

Nisini

Santangelo

Giannini

et al. 2015

ApJ

126

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“…High angular resolution observations in SiO lines (Dutrey et al 1997) were found in agreement with a structure of incomplete and fragmented bow-shocks caused by discrete episodes of ejection from the central star (’molecular bullets’). Strong H 2 O and high-J CO line emission was detected toward this and other L1448 bright spots by Nisini et al (2000, 2013), Santangelo et al (2012) and Gomez-Ruiz et al (2013) indicating the presence of very dense (∼ 10 6 cm −3 ) molecular gas at temperatures in excess of 500 K.…”

Section: The Source Samplesupporting

confidence: 59%

“…A multiline analysis of CS and its isotopic variations allowed to study the density structure of the molecular outflow (Gómez-Ruiz et al 2015). The line profiles can be well fitted by a combination of two exponential laws that are remarkably similar to what previously found using CO by Lefloch et al (2012).…”

Section: Chemical Evolution Along Star Formationmentioning

confidence: 99%

Astrochemical evolution along star formation: overview of the IRAM Large Program ASAI

Leflóch

Bachiller

Ceccarelli

et al. 2018

Monthly Notices of the Royal Astronomical Society

103

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Evidence is mounting that the small bodies of our Solar System, such as comets and asteroids, have at least partially inherited their chemical composition from the first phases of the Solar System formation. It then appears that the molecular complexity of these small bodies is most likely related to the earliest stages of star formation. It is therefore important to characterize and to understand how the chemical evolution changes with solar-type protostellar evolution. We present here the Large Program "Astrochemical Surveys At IRAM" (ASAI). Its goal is to carry out unbiased millimeter line surveys between 80 and 272 GHz of a sample of ten template sources, which fully cover the first stages of the formation process of solar-type stars, from prestellar cores to the late protostellar phase. In this article, we present an overview of the surveys and results obtained from the analysis of the 3 mm band observations. The number of detected main isotopic species barely varies with the evolutionary stage and is found to be very similar to that of massive star-forming regions. The molecular content in O- and C- bearing species allows us to define two chemical classes of envelopes, whose composition is dominated by either a) a rich content in O-rich complex organic molecules, associated with hot corino sources, or b) a rich content in hydrocarbons, typical of Warm Carbon Chain Chemistry sources. Overall, a high chemical richness is found to be present already in the initial phases of solar-type star formation.

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“…Mid-J CO transitions are good tracers of warm gas in molecular outflows compared to low-J transitions (Gomez-Ruiz et al 2013). Since we have found that CO (2-1) and CO (6-5)/(7-6) probe different gas (Section 3.3) and the step 3 summation maps likely trace the collimated jet better (Section 4.1.1), we use the CO (6-5) and (7-6) maps and their step 3 summation maps to study the shocked gas.…”

Section: Warm Gas Propertiesmentioning

confidence: 99%

Iras 16253–2429: The First Proto-Brown Dwarf Binary Candidate Identified Through the Dynamics of Jets*

Hsieh

Lai

Беллоче

et al. 2016

ApJ

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The formation mechanism of brown dwarfs (BDs) is one of the long-standing problems in star formation because the typical Jeans mass in molecular clouds is too large to form these substellar objects. To answer this question, it is crucial to study a BD at the embedded phase. IRAS 16253-2429 is classified as a very low luminosity object (VeLLO) with internal luminosity < 0.1L . VeLLOs are believed to be very low-mass protostars or even proto-BDs. We observed the jet/outflow driven by IRAS 16253-2429 in CO (2-1), (6-5), and (7-6) using the IRAM 30 m and APEX telescopes and the SMA in order to study its dynamical features and physical properties. Our SMA map reveals two protostellar jets, indicating the existence of a proto-binary system as implied by the precessing jet detected in H 2 emission. We detect a wiggling pattern in the position-velocity diagrams along the jet axes, which is likely due to the binary orbital motion. Based on this, we derive the current mass of the binary as ∼0.032M . Given the low envelope mass, IRAS 16253-2429 will form a binary that probably consist of one or two BDs. Furthermore, we found that the outflow force as well as the mass accretion rate are very low based on the multi-transition CO observations, which suggests that the final masses of the binary components are at the stellar/substellar boundary. Since IRAS 16253 is located in an isolated environment, we suggest that BDs can form through fragmentation and collapse like low-mass stars.

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Warm gas in protostellar outflows

Cited by 13 publications

References 42 publications

[O I] 63μm JETS IN CLASS 0 SOURCES DETECTED BYHERSCHEL

[O I] 63μm JETS IN CLASS 0 SOURCES DETECTED BYHERSCHEL

Astrochemical evolution along star formation: overview of the IRAM Large Program ASAI

Iras 16253–2429: The First Proto-Brown Dwarf Binary Candidate Identified Through the Dynamics of Jets*

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