March 27, 2013

Hunting high-mass stars with Herschel

In this new view of a vast star-forming cloud called W3, ESA's Herschel space observatory tells the story of how massive stars are born.

In this image, the low-mass protostars are seen as tiny yellow dots embedded in cool red filaments, while the highest-mass stars - with greater than eight times the mass of our Sun - emit intense radiation, heating up the gas and dust around them and appearing here in blue.
This three-colour image of the W3 giant molecular cloud combines Herschel bands at 70 µm (blue), 160 µm (green) and 250 µm (red). W3 is an enormous stellar nursery about 6200 light-years away in the Perseus Arm, one of the Milky Way galaxy's main spiral arms, that hosts both low- and high-mass star formation. In this image, the low-mass protostars are seen as tiny yellow dots embedded in cool red filaments, while the highest-mass stars - with greater than eight times the mass of our Sun - emit intense radiation, heating up the gas and dust around them and appearing here in blue. Credit: ESA/PACS & SPIRE consortia, A. Rivera-Ingraham & P.G. Martin, Univ. Toronto, HOBYS Key Programme (F. Motte)

W3 is a giant molecular cloud containing an enormous stellar nursery, some 6200 light-years away in the Perseus Arm, one of our Milky Way Galaxy's main spiral arms.

Spanning almost 200 light-years, W3 is one of the largest star-formation complexes in the outer Milky Way, hosting the formation of both low- and high-mass stars. The distinction is drawn at eight times the mass of our own Sun: above this limit, stars end their lives as supernovas.

Dense, bright blue knots of hot dust marking massive star formation dominate the upper left of the image in the two youngest regions in the scene: W3 Main and W3 (OH). Intense radiation streaming away from the stellar infants heats up the surrounding dust and gas, making it shine brightly in Herschel's infrared-sensitive eyes.

Older high-mass stars are also seen to be heating up dust in their environments, appearing as the blue regions labelled AFGL 333 in the lower left of the annotated version of the image, and the loop of KR 140, at bottom right.

Annotated image of the W3 giant molecular cloud combining Herschel bands at 70 ?m (blue), 160 ?m (green) and 250 ?m (red). Credit: ESA/PACS & SPIRE consortia, A. Rivera-Ingraham & P.G. Martin, Univ. Toronto, HOBYS Key Programme (F. Motte)
Annotated image of the W3 giant molecular cloud combining Herschel bands at 70 µm (blue), 160 µm (green) and 250 µm (red). Credit: ESA/PACS & SPIRE consortia, A. Rivera-Ingraham & P.G. Martin, Univ. Toronto, HOBYS Key Programme (F. Motte)

Read the complete news on ESA's website

Publication:

"Herschel observations of the W3 GMC: clues to the formation of clusters of high-mass stars"