X-ray properties of the young open clusters HM1 and IC2944/2948

Abstract

Using XMM data, we study for the first time the X-ray emission of HM1 and IC2944/2948. Low-mass, pre-main-sequence objects with an age of a few Myr are detected, as well as a few background or foreground objects. Most massive stars in both clusters display the usual high-energy properties of that type of objects, though with log(Lx/Lbol) apparently lower in HM1 than in IC2944/2948. Compared with studies of other clusters, it seems that a low signal-to-noise ratio at soft energies, due to the high extinction, may be the main cause of this difference. In HM1, the two Wolf-Rayet stars show contrasting behaviors: WR89 is extremely bright, but much softer than WR87. It remains to be seen whether wind-wind collisions or magnetically confined winds can explain these emissions. In IC2944/2948, the X-ray sources concentrate around HD101205; a group of massive stars to the north of this object is isolated, suggesting that there exist two subclusters in the field-of-view.

29 pages in total with 10 figures (12 pages paper + supplementary material), accepted by A&A

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Cited by in corpus (11)

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• X-ray and optical spectroscopy of the massive young open cluster IC1805
• Candidate X-ray-Emitting OB Stars in the MYStIX Massive Star-Forming Regions
• Investigating 39 Galactic Wolf-Rayet stars with VLTI/GRAVITY: Uncovering A Long Period Binary Desert
• A deep and wide-field view at the IC 2944 / 2948 complex in Centaurus
• Census of High- and Medium-mass Protostars V. CO Abundance and the Galactic $X_{\text{CO}}$ Factor
• A Deep Chandra Observation of the Giant HII Region N11 I. X-ray Sources in the Field
• Fundamental parameters of the massive eclipsing binary HM1 8