New blackhole mass measuring method

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Discussion Overview

The discussion centers around a new method for measuring black hole masses using molecular gas kinematics, particularly in the context of the galaxy NGC4526. Participants explore the implications of this method for understanding black hole and galaxy co-evolution, as well as the potential for broader applications in astrophysics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants highlight the use of radio frequency emissions from carbon monoxide molecules to measure the rotation of gas clouds around black holes, emphasizing the significance of Doppler shifts.
  • Others mention the correlation between supermassive black hole masses and various galaxy properties, suggesting that this relationship may indicate a co-evolution of galaxies and black holes.
  • A participant provides links to multiple articles, including preprints and supplementary materials, to support the discussion and enhance understanding of the new measurement method.
  • There is mention of the limitations of current methods for measuring black hole masses and the potential for this new technique to increase the number of accessible measurements significantly.

Areas of Agreement / Disagreement

Participants express interest in the new method and its implications, but there is no consensus on the broader impacts or the validity of the claims made in the articles referenced. The discussion remains open with multiple viewpoints presented.

Contextual Notes

Participants note that the number of reliably measured black hole masses is small and that existing methods are limited, which may affect the interpretation of results from the new technique.

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Mordred said:
Thought this article may spark some interest if it works out we may gain a better understand of BH's.
http://www.sciencedaily.com/releases/2013/01/130130132324.htm

Here is an earlier article by some of the same authors that might be interesting as background to the one you mention:
http://arxiv.org/abs/1102.4877

Using the radio frequency emitted by carbon monoxide molecules to measure rotation---the swirling of gas cloud around a central mass---the doppler shift of the gas coming towards versus the gas going from. It's an interesting business. I hope we can sometime get an online link to the Nature article. I don't have one.

Timothy A. Davis, Martin Bureau, Michele Cappellari, Marc Sarzi, Leo Blitz. A black-hole mass measurement from molecular gas kinematics in NGC4526. Nature, 2013

Here's another link to comment on the article:
http://arstechnica.com/science/2013/01/better-black-hole-mass-estimates-in-hours/

Here's a link to supplementary material:
http://www.nature.com/nature/journal/vaop/ncurrent/extref/nature11819-s1.pdf

Here's the abstract of the article just published in Nature (but not the full article):
http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11819.html
==quote==
A black-hole mass measurement from molecular gas kinematics in NGC4526
...
...
The masses of the supermassive black holes found in galaxy bulges are correlated with a multitude of galaxy properties1, 2, leading to suggestions that galaxies and black holes may evolve together3. The number of reliably measured black-hole masses is small, and the number of methods for measuring them is limited4, holding back attempts to understand this co-evolution. Directly measuring black-hole masses is currently possible with stellar kinematics (in early-type galaxies), ionized-gas kinematics (in some spiral and early-type galaxies5, 6, 7) and in rare objects that have central maser emission8. Here we report that by modelling the effect of a black hole on the kinematics of molecular gas it is possible to fit interferometric observations of CO emission and thereby accurately estimate black-hole masses. We study the dynamics of the gas in the early-type galaxy NGC 4526, and obtain a best fit that requires the presence of a central dark object of 4.5+4.2-3.1  × 108 solar masses (3σ confidence limit). With the next-generation millimetre-wavelength interferometers these observations could be reproduced in galaxies out to 75 megaparsecs in less than 5 hours of observing time. The use of molecular gas as a kinematic tracer should thus allow one to estimate black-hole masses in hundreds of galaxies in the local Universe, many more than are accessible with current techniques.
==endquote==
 
Last edited by a moderator:
Awesome thanks for the other links, Its always nice getting the non pop media articles lol
 
Preprint just posted half an hour ago! Now we have free access, not limited to subscribers to Nature.
http://arxiv.org/abs/1301.7184
A black-hole mass measurement from molecular gas kinematics in NGC4526
Timothy A. Davis, Martin Bureau, Michele Cappellari, Marc Sarzi, Leo Blitz
(Submitted on 30 Jan 2013)
The masses of the supermassive black-holes found in galaxy bulges are correlated with a multitude of galaxy properties, leading to suggestions that galaxies and black-holes may evolve together. The number of reliably measured black-hole masses is small, and the number of methods for measuring them is limited, holding back attempts to understand this co-evolution. Directly measuring black-hole masses is currently possible with stellar kinematics (in early-type galaxies), ionised-gas kinematics (in some spiral and early-type galaxies) and in rare objects which have central maser emission. Here we report that by modelling the effect of a black-hole on the kinematics of molecular gas it is possible to fit interferometric observations of CO emission and thereby accurately estimate black hole masses. We study the dynamics of the gas in the early-type galaxy NGC4526, and obtain a best fit which requires the presence of a central dark-object of 4.5(+4.2-3.0)x10^8 Msun (3 sigma confidence limit). With next generation mm-interferometers (e.g. ALMA) these observations could be reproduced in galaxies out to 75 megaparsecs in less the 5 hours of observing time. The use of molecular gas as a kinematic tracer should thus allow one to estimate black-hole masses in hundreds of galaxies in the local universe, many more than accessible with current techniques.
Comments: To appear in Nature online on 30/01/2013. 3 Pages, 2 Figures (plus two pages of supplementary information)
 

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