Star cluster shines in new look from NASA’s Chandra

Westerlund 1 is the largest and closest “tremendous” star cluster to Earth. New knowledge from NASA’s Chandra X-ray Observatory, together with different NASA telescopes, helps astronomers delve deeper into this galactic manufacturing facility the place stars are vigorously being produced.

That is the primary knowledge to be publicly launched from a venture known as the Prolonged Westerlund 1 and a couple of Open Clusters Survey, or EWOCS, led by astronomers from the Italian Nationwide Institute of Astrophysics in Palermo. As a part of EWOCS, Chandra noticed Westerlund 1 for about 12 days in total.

Presently, solely a handful of stars kind in our galaxy annually, however up to now the scenario was completely different. The Milky Way used to provide many extra stars, doubtless hitting its peak of churning out dozens or tons of of stars per yr about 10 billion years in the past after which steadily declining ever since.

Astronomers assume that almost all of this star formation came about in huge clusters of stars, generally known as “tremendous star clusters,” like Westerlund 1. These are younger clusters of stars that comprise greater than 10,000 occasions the mass of the sun. Westerlund 1 is between about 3 million and 5 million years previous.

This new picture reveals the brand new deep Chandra knowledge together with beforehand launched knowledge from NASA’s Hubble Area Telescope. The X-rays detected by Chandra present young stars (largely represented as white and pink) in addition to diffuse heated fuel all through the cluster (coloured pink, inexperienced, and blue, so as of accelerating temperatures for the fuel). Lots of the stars picked up by Hubble seem as yellow and blue dots.

Only some tremendous star clusters nonetheless exist in our galaxy, however they provide necessary clues about this earlier period when most of our galaxy’s stars shaped. Westerlund 1 is the largest of those remaining tremendous star clusters within the Milky Way and comprises a mass between 50,000 and 100,000 Suns. Additionally it is the closest tremendous star cluster to Earth at about 13,000 light-years.

These qualities make Westerlund 1 a wonderful goal for finding out the affect of an excellent star cluster’s surroundings on the formation means of stars and planets in addition to the evolution of stars over a broad vary of lots.

This new deep Chandra dataset of Westerlund 1 has greater than tripled the variety of X-ray sources identified within the cluster. Earlier than the EWOCS venture, Chandra had detected 1,721 sources in Westerlund 1. The EWOCS knowledge discovered virtually 6,000 X-ray sources, together with fainter stars with decrease lots than the sun. This offers astronomers a brand new inhabitants to check.

One revelation is that 1,075 stars detected by Chandra are squeezed into the center of Westerlund 1 inside 4 light-years of the cluster’s middle. For a way of how crowded that is, 4 light-years is concerning the distance between the sun and the following closest star to Earth.

The diffuse emission seen within the EWOCS knowledge represents the primary detection of a halo of sizzling fuel surrounding the middle of Westerlund 1, which astronomers assume might be essential in assessing the cluster’s formation and evolution, and giving a extra exact estimate of its mass.

A paper published within the journal Astronomy and Astrophysics, led by Mario Guarcello from the Italian Nationwide Institute of Astrophysics in Palermo, discusses the survey and the primary outcomes.

Comply with-up papers will focus on extra concerning the outcomes, together with detailed research of the brightest X-ray sources. This future work will analyze different EWOCS observations, involving NASA’s James Webb Area Telescope and NICER (Neutron Star Inside Composition Explorer).

NASA’s Marshall Area Flight Middle manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Middle controls science from Cambridge Massachusetts and flight operations from Burlington, Massachusetts.