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

We report on the Chandra X-ray Observatory and Hubble Space Telescopeobservation of two low core density globular clusters, NGC6144 and E3. Bycomparing the number of X-ray sources inside the half-mass radius to thoseoutside, we found 6 X-ray sources within the half-mass radius of NGC6144, amongwhich 4 are expected to be background sources; 3 X-ray sources are also foundwithin the half-mass radius of E3, of which 3 is expected to be backgroundsource. Therefore, we cannot exclude that all our sources are backgroundsources. However, combining the results from X-ray and optical observations, wefound that 1-2 sources in NGC6144 and 1 source in E3 are likely to becataclysmic variables and that 1 source in NGC6144 is an active binary, basedon the X-ray and optical properties. The number of faint X-ray sources inNGC6144 and E3 found with Chandra and HST is higher than a prediction based oncollision frequency, but is closer to that based on mass. Our observationsstrongly suggest that the compact binary systems in NGC6144 and E3 areprimordial in origin.

X-ray and Optical Study of Low Core Density Globular Clusters NGC6144 and E3