← Search

Table · dataset · 2023

VLA 1.3 & 5cm observations of 9 EGOs in the MW

Listed in IVOA Registry (Virtual Observatory)

We have observed a sample of nine Extended Green Objects (EGOs) at 1.3 and 5cm with the Very Large Array (VLA) with subarcsecond resolution and ~7-14{mu}Jy/beam-sensitivities in order to characterize centimeter continuum emission as it first appears in these massive protoclusters.

Description

We find an EGO-associated continu um emission --within 1" of the extended 4.5{mu}m emission-- in every field, which is typically faint (order 10^1^-10^2^{mu}Jy) and compact (unresolved at 0.3"-0.5").

The derived spectral indices of our 36 total detections are consistent with a wide array of physical processes, including both non-thermal (19% of detections) and thermal free-free processes (e.g., ionized jets and compact HII regions, 78% of sample) and warm dust (1 source). We also find an EGO-associated 6.7GHz CH_3_OH and 22GHz H_2_O maser emission in 100% of the sample and a NH_3_(3,3) masers in ~45%; we do not detect any NH_3_(6,6) masers at ~5.6mJy/beam sensitivity.

Read the rest (1 more)

We find statistically-significant correlations between Lradio and Lbol at two physical scales and three frequencies, consistent with thermal emission from ionized jets, but no correlation between L_H2O_ and L_radio_ for our sample. From these data, we conclude that EGOs likely host multiple different centimeter continuum-producing processes simultaneously. Additionally, at our ~1000au resolution, we find that all EGOs except G18.89-0.47 contain 1~2 massive sources based on the presence of CH_3_OH maser groups, which is consistent with our previous work suggesting that these are typical massive protoclusters, in which only one to a few of the young stellar objects are massive.

Links

Where it is published

Documentation and papers

Catalogue records · 2

Topics

Stated by source
Radio
Provenance · 1 source records, 8 field assertions
SourceKeyLast seenRaw
IVOA Registry (Virtual Observatory)ivo://cds.vizier/j/apj/923/26314 d agoJSON v1
FieldAssertionExtractorEvidence
access_levelsource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[field].local:field:astronomymapping · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].ivoa_waveband:radiosource · IVOA Registryconnector:ivoa_registry@1.0.0
descriptionsource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_description
license_textsource · IVOA Registryconnector:ivoa_registry@1.0.0
publication_datesource · IVOA Registryconnector:ivoa_registry@1.0.0
titlesource · IVOA Registryconnector:ivoa_registry@1.0.0rr.resource.res_title
updated_datesource · IVOA Registryconnector:ivoa_registry@1.0.0