AMI Large Array radio continuum observations of Spitzer c2d small clouds and cores★

Scaife, Anna M. M.; Curtis, Emily I.; Davies, Matthew; Franzen, T. M. O.; Grainge, Keith; Hobson, M.; Hurley‐Walker, N.; Lasenby, A.; Olamaie, Malak; Pooley, G. G.; Rodríguez‐Gonzálvez, Carmen; Saunders, Richard D. E.; Schammel, Michel P.; Scott, Paul F.; Shimwell, T. W.; Titterington, D.; Waldram, Elizabeth; Zwart, Jonathan T. L.

doi:10.1111/j.1365-2966.2010.17644.x

Cited by 13 publications

(1 citation statement)

References 73 publications

(178 reference statements)

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“…Rodríguez et al (1999) achieved sensitivity up to 10 μJy, with observations at 3.6 and 6 cm, but their sample was limited to the central part of the NGC 1333 region in Perseus and the resolution was around 5″. The AMI Consortium: Scaife et al (2011aScaife et al ( , 2011bScaife et al ( , 2012aScaife et al ( , 2012b observed selected protostars in Perseus, Serpens, Taurus, and several isolated cores at low resolution (30″) and sensitivity up to 15 μJy at 1.8 cm. The Gould's Belt Very Large Array (VLA) Survey targeted large sample of protostars in selected star-forming regions with 16 μJy sensitivity and resolution up to 0 4 (Dzib et al 2013(Dzib et al , 2015Kounkel et al 2014;Ortiz-León et al 2015;Pech et al 2016) in C-band (4.1 and 6.4 cm).…”

Section: Introductionmentioning

confidence: 99%

The VLA Nascent Disk And Multiplicity Survey of Perseus Protostars (VANDAM). III. Extended Radio Emission from Protostars in Perseus

Tychoniec¹,

Tobin²,

Karska³

et al. 2017

ApJ

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Centimeter continuum emission from protostars offers insight into the innermost part of the outflows, as shock-ionized gas produces free-free emission. We observed a complete population of Class 0 and I protostars in the Perseus molecular cloud at 4.1 and 6.4 cm with resolution and sensitivity superior to previous surveys. From a total of 71 detections, eight sources exhibit resolved emission at 4.1 cm and/or 6.4 cm. In this paper, we focus on this subsample, analyzing their spectral indices along the jet and their alignment with respect to the large-scale molecular outflow. Spectral indices for fluxes integrated toward the position of the protostar are consistent with free-free thermal emission. The value of the spectral index along a radio jet decreases with distance from the protostar. For six sources, emission is well aligned with the outflow central axis, showing that we observe the ionized base of the jet. This is not the case for two sources, where we note misalignment of the emission with respect to the large-scale outflow. This might indicate that the emission does not originate in the radio jet, but rather in an ionized outflow cavity wall or disk surface. For five of the sources, the spectral indices along the jet decrease well below the thermal free-free limit of −0.1 with 2s > significance. This is indicative of synchrotron emission, meaning that high-energy electrons are being produced in the outflows close to the disk. This result can have far-reaching implications for the chemical composition of the embedded disks.

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Section: Introductionmentioning

confidence: 99%

The VLA Nascent Disk And Multiplicity Survey of Perseus Protostars (VANDAM). III. Extended Radio Emission from Protostars in Perseus

Tychoniec¹,

Tobin²,

Karska³

et al. 2017

ApJ

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Radio Emission from YSOs: Tackling the (Reverse) Luminosity Problem

Scaife

2014

The Labyrinth of Star Formation

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Radio jets from young stellar objects

Anglada

Rodrı́guez²,

Carrasco-González³

2018

Astron Astrophys Rev

137

151

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Jets and outflows are ubiquitous in the process of formation of stars since outflow is intimately associated with accretion. Free-free (thermal) radio continuum emission in the centimeter domain is associated with these jets. The emission is relatively weak and compact, and sensitive radio interferometers of high angular resolution are required to detect and study it. One of the key problems in the study of outflows is to determine how they are accelerated and collimated. Observations in the cm range are most useful to trace the base of the ionized jets, close to the young central object and the inner parts of its accretion disk, where optical or near-IR imaging is made difficult by the high extinction present. Radio recombination lines in jets (in combination with proper motions) should provide their 3D kinematics at very small scale (near their origin). Future instruments such as the Square Kilometre Array (SKA) and the Next Generation Very Large Array (ngVLA) will be crucial to perform this kind of sensitive observations. Thermal jets are associated with both high and low mass protostars and possibly even with objects in the substellar domain. The ionizing mechanism of these radio jets appears to be related to shocks in the associated outflows, as suggested by the observed correlation between the centimeter luminosity and the outflow momentum rate. From this correlation and that of the centimeter luminosity with the bolometric luminosity of the system it will be possible to discriminate between unresolved HII regions and jets, and to infer additional physical properties of the embedded objects. Some jets associated with young stellar objects (YSOs) show indications of nonthermal emission (negative spectral indices) in part of their lobes. Linearly polarized synchrotron emission has been found in the jet of HH 80-81, allowing one to measure the direction and intensity of the jet magnetic field, a key ingredient to determine the collimation and ejection mechanisms. As only a fraction of the emission is polarized, very sensitive observations such as those that will be feasible with the interferometers previously mentioned are required to perform studies in a large sample of sources. Jets are present in many kinds of astrophysical scenarios. Characterizing radio jets in YSOs, where thermal emission allows one to determine their physical conditions in a reliable way, would also be useful in understanding acceleration and collimation mechanisms in all kinds of astrophysical jets, such as those associated with stellar and supermassive black holes and planetary nebulae.

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AMI Large Array radio continuum observations of Spitzer c2d small clouds and cores★

Cited by 13 publications

References 73 publications

The VLA Nascent Disk And Multiplicity Survey of Perseus Protostars (VANDAM). III. Extended Radio Emission from Protostars in Perseus

The VLA Nascent Disk And Multiplicity Survey of Perseus Protostars (VANDAM). III. Extended Radio Emission from Protostars in Perseus

Radio Emission from YSOs: Tackling the (Reverse) Luminosity Problem

Radio jets from young stellar objects

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