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View Full Version here: : Neutron star merger provides independent Hubble constant measurement


gary
20-10-2017, 04:27 PM
In a accelerated article preview (http://www.nature.com/nature/journal/vaap/ncurrent/pdf/nature24471.pdf)in Nature published on 16 Oct 2017,
the LIGO Scientific Collaboration and the Virgo Collaboration report
on a new measurement of the Hubble constant, Ho (H-zero),
using observations from the recent neutron star merger event.

They report Ho = 70 (+12.0/-8.0) kilometres per second per megaparsec,
which is "consistent with existing measurements, while being completely independent of them".

They also report, "Our measurements do not require any form of cosmic ‘distance ladder’;
the gravitational-wave analysis directly estimates the luminosity distance out to cosmological scales".

Abstract here :-
http://www.nature.com/nature/journal/vaap/ncurrent/full/nature24471.html

Article here :-
http://www.nature.com/nature/journal/vaap/ncurrent/pdf/nature24471.pdf

multiweb
20-10-2017, 04:38 PM
Great to get a confirmation from another source. :thumbsup:

xelasnave
20-10-2017, 06:58 PM
I thought the last few lines outside what I would have though went in a paper.
Alex

xelasnave
21-10-2017, 08:56 AM
This......

. The coming years can be expected to bring additional multi-messenger binary neutron star events, as well as numerous detections of binary black hole mergers25, for which electromagnetic counterparts are not expected. Combining subsequent independent measurements of H0 from these future standard sirens will only improve the estimate made from GW170817, leading to an era of percent-level gravitational-wave cosmology.

Sounds like an add.......

alex

markbakovic
21-10-2017, 08:22 PM
it kinda goes to "directions for future research" though, which totally fits in a discussion. It also serves as a mild antidote to the current debate about the constitution of the National Science Foundation (who funded LIGO) review panels (some polly reckons they should contain his mates who don't think spending more than $3 on a mirror is "in the taxpayer's interest" because you can't bomb a resource rich failed state with the word "interferometer"): ie This Is A Big Deal, Possibly The Biggest Deal In The Last 50 Years.

If you don't brag like a salesman about what the funding you get is paying for, it seems like the assumption is that it must have been wasted, because politicians have discovered it's easier to say "Do you have an ill-informed opinion? I have it too!" than to actually do their job of convincing the public that the things government spends money on are actually good things to spend it on. Unless that thing is paying them millions in campaign donations, of course, which Advancing Human Understanding LLC has f-all capacity to do...

</rant>

xelasnave
22-10-2017, 07:35 AM
Fair enough but I just dont think such should be in such releases.
The job of convincing should be outside the document... or if this is acceptable why not add at the end of such news.... support our research and subscibe like utube...or the like.

Well you wouldnt do that and any lesser milder approach such as I referred to I dont find any more acceptable. Just dont think such personal comment has any place in the document it is an opinion that adds nothing to the document.



alex

Shiraz
22-10-2017, 02:40 PM
amazing - no heroic assumptions needed, and still a consistent result.