CSIRO radio telescope helped scientists to study raw star gas

In blue, the carbon monoxide gas detected in and around the Spiderweb. Credit: B. Emonts et al (CSIRO/ATCA)
In blue, the carbon monoxide gas detected in and around the Spiderweb. Credit: B. Emonts et al (CSIRO/ATCA)

Main Point:

Astronomers have studied the raw gas, cold molecular hydrogen gas, H2 that is thought to be involved in the development of early stars, when the universe was just three billion years old.

Publishing in:

Monthly Notices of the Royal Astronomical Society

Study Further:

Astronomers used CSIRO’s Australia Telescope Compact Array telescope near Narrabri, NSW, to study those gases. They used a ‘tracer’ gas, carbon monoxide (CO) that emits radio waves to reveal these gases.

“It one of very few telescopes in the world that can do such difficult work, because it is both extremely sensitive and can receive radio waves of the right wavelengths,” says CSIRO astronomer Professor Ron Ekers.

Astronomers studied “massive, distant conglomerate of star-forming ‘clumps’ or ‘proto-galaxies’ that are in the process of coming together as a single massive galaxy. This structure, called the Spiderweb, lies more than ten thousand million light-years away [at a redshift of 2.16],” as reported in CSIRO website.

Astronomers found that the Spiderweb has about sixty thousand million [6 x 1010] times the mass of the Sun in molecular hydrogen gas present in an area of over a quarter of a million light-years. This has been considered as the fuel for the star-formation. “Indeed, it is enough to keep stars forming for at least another 40 million years,” says Emonts.


The Compact Array’s ability to detect CO is due to an upgrade that has boosted its bandwidth — the amount of radio spectrum it can see at any one time — sixteen-fold [from 256 MHz to 4 GHz], and made it far more sensitive.




B. H. C. Emonts, I. Feain, H. J. A. Roettgering, G. Miley, N. Seymour, R. P. Norris, C. L. Carilli, M. Villar-Martin, M. Y. Mao, E. M. Sadler, R. D. Ekers, G. A. van Moorsel, R. J. Ivison, L. Pentericci, C. N. Tadhunter, & D. J. Saikia (2013). CO(1-0) detection of molecular gas in the massive Spiderweb Galaxy (z=2) Monthly Notices of the Royal Astronomical Society arXiv: 1301.6012v1

Aravena, M., Murphy, E., Aguirre, J., Ashby, M., Benson, B., Bothwell, M., Brodwin, M., Carlstrom, J., Chapman, S., Crawford, T., de Breuck, C., Fassnacht, C., Gonzalez, A., Greve, T., Gullberg, B., Hezaveh, Y., Holder, G., Holzapfel, W., Keisler, R., Malkan, M., Marrone, D., McIntyre, V., Reichardt, C., Sharon, K., Spilker, J., Stalder, B., Stark, A., Vieira, J., & Weiss, A. (2013). Large gas reservoirs and free-free emission in two lensed star-forming galaxies at z = 2.7 Monthly Notices of the Royal Astronomical Society DOI: 10.1093/mnras/stt741

Usman Zafar Paracha

Usman Zafar Paracha is Assistant Professor, Pharmaceutics, in Hajvery University, Lahore, Pakistan.