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

Context: Molecular hydrogen (H2) is the most abundant molecule in thecircumstellar (CS) environments of young stars, and is a key element in giantplanet formation. The measurement of the H2 content provides the most directprobe of the total amount of CS gas, especially in the inner warmplanet-forming regions of the disks.  Aims: Most Herbig Be stars (HBes) are distant from the Sun and their natureand evolution are still debated. We therefore conducted mid-infraredobservations of H2 as a tracer of warm gas around HBes known to have gas-richCS environments.  Methods: We report a search for the H2 S(1) emission line at 17.0348 micronsin the CS environments of 5 HBes with the high resolution spectroscopic mode ofVISIR (ESO VLT Imager and Spectrometer for the mid-InfraRed).  Results: No source shows evidence for H2 emission at 17.0348 microns.Stringent 3sigma upper limits on the integrated line fluxes are derived.Depending on the adopted temperature, limits on column densities and masses ofwarm gas are also estimated. These non-detections constrain the amount of warm(>150 K) gas in the immediate CS environments of our target stars to be lessthan 1-10 Jupiter masses.

Searching for molecular hydrogen mid-infrared emission in the circumstellar environments of Herbig Be stars