English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Core accretion models of massive star formation require the existence ofstable massive starless cores, but robust observational examples of suchobjects have proven elusive. We report subarcsecond-resolution SMA 1.3 mm, 1.1mm, and 0.88 mm and VLA 1.3 cm observations of an excellent massive starlesscore candidate, G11.92-0.61-MM2, initially identified in the course of studiesof GLIMPSE Extended Green Objects (EGOs). Separated by ~7.2" from the nearbyMM1 protostellar hot core, MM2 is a strong, compact dust continuum source(submillimeter spectral index alpha=2.6+/-0.1), but is devoid of star formationindicators. In contrast to MM1, MM2 has no masers, no centimeter continuum, andno (sub)millimeter wavelength line emission in ~24 GHz of bandwidth observedwith the SMA, including N2H+(3-2), HCO+(3-2), and HCN(3-2). Additionally, thereis no evidence for an outflow driven by MM2. The (sub)millimeter spectralenergy distribution (SED) of MM2 is best fit with a dust temperature of ~17-19K and luminosity of ~5-7 L_sun. The combined physical properties of MM2, asinferred from its dust continuum emission, are extreme: M>30 M_sun within aradius<1000 AU, N(H2)>10^25 cm^-2 and n(H2)>10^9 cm^-3. Comparison of themolecular abundance limits derived from our SMA observations with gas-grainchemical models indicates that extremely dense (n(H)>>10^8 cm^-3), cold (<20 K)conditions are required to explain the lack of observed (sub)millimeter lineemission, consistent with the dust continuum results. Our data suggest thatG11.92-0.61-MM2 is the best candidate for a bonafide massive prestellar corefound to date, and a promising target for future, higher-sensitivityobservations.

G11.92-0.61-MM2: A Bonafide Massive Prestellar Core?