The Race for Gold*
|Gold ring. Credit: P.Edmonds|
I didn't know the merger story was a serious contender for making heavy elements like gold until this paper appeared on the arXiv: "Smoking Gun Or Smoldering Embers? A Possible R-Process Kilonova Associated with the Short-Hard GRB 130603B". A short-hard gamma ray burst (GRB) is thought to occur when the merger described above occurs, producing a powerful explosion and a burst of gamma rays. A chain of nuclear reactions called the "r-process" should then occur, producing heavy elements like gold and a second source of radiation called a "kilonova", a few days after the explosion.
|Edo Berger at the CfA press conference announcing possible detection of a kilonova. Credit: CfA/Edo Berger|
"We note that we felt compelled to submit this provisional report of our work, despite our HST DDT program being incomplete, due to other authors having already posted an analysis of the publicly available first epoch data."That’s not a statement you see every day on the arXiv, and I look at it regularly. The good news is that they also argued a kilonova may have been detected, but they cautioned that "we cannot yet say whether the light is transient in nature".
"We didn't ask in the first instance, but after our experience with the first epoch, we argued that it was important to give sufficient time to do a careful analysis of the data without being rushed into publication."
Publicity images from the Hubble Space Telescope for the Nature paper by Nial Tanvir et al. Credit: NASA, ESA, N. Tanvir (University of Leicester), A. Fruchter (STScI), and A. Levan (University of Warwick)
"Nature were aware that there was a likelihood that the result of the second epoch would be published/publicised first elsewhere if their publication was not sufficiently quick. Of course, the normal refereeing process had to be adhered to, which could have delayed things, but thankfully didn't."
An artist's impression of two neutron stars merging. Credit: Dana Berry, SkyWorks Digital, Inc.
|Daniel Kasen from Berkeley Astronomy Department. Credit: Berkeley and Daniel Kasen|
"Daniel Kasen of the University of California, Berkeley, thinks the idea is intriguing, but he points out that we don't know for sure how common neutron star mergers are.
"For reasonable rates, if they're ejecting that much mass, it's plausible or likely that they're ejecting a big chunk of the heavy elements of the universe," he says. "But it would be helpful if they get more data points.""