Skip to main content Accessibility help
×
Home
Hostname: page-component-55b6f6c457-cn8nj Total loading time: 0.16 Render date: 2021-09-27T18:37:44.295Z Has data issue: true Feature Flags: { "shouldUseShareProductTool": true, "shouldUseHypothesis": true, "isUnsiloEnabled": true, "metricsAbstractViews": false, "figures": true, "newCiteModal": false, "newCitedByModal": true, "newEcommerce": true, "newUsageEvents": true }

A Measurement of the Hubble Constant by the Megamaser Cosmology Project

Published online by Cambridge University Press:  16 July 2018

James Braatz
Affiliation:
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
James Condon
Affiliation:
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
Christian Henkel
Affiliation:
Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany Astronomy Department, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia
Jenny Greene
Affiliation:
Department of Astrophysics, Princeton University, Princeton, NJ, 08544, USA
Fred Lo
Affiliation:
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA
Mark Reid
Affiliation:
Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA
Dominic Pesce
Affiliation:
National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903, USA Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904, USA
Feng Gao
Affiliation:
Shanghai Astronomical Observatory, Chinese Academy of Sciences, 200030 Shanghai, China
Violette Impellizzeri
Affiliation:
Joint ALMA Office, Alonso de Cordova 3107, Vitacura, Santiago, Chile
Cheng-Yu Kuo
Affiliation:
Department of Physics, National Sun Yat-Sen University, No. 70, Lianhai Road, Gushan Dist., 804 Kaohsiung City, Taiwan, R.O.C.
Wei Zhao
Affiliation:
Shanghai Astronomical Observatory, Chinese Academy of Sciences, 200030 Shanghai, China
Anca Constantin
Affiliation:
Department of Physics and Astronomy, James Madison University, Harrisonburg, VA 22807, USA
Lei Hao
Affiliation:
Shanghai Astronomical Observatory, Chinese Academy of Sciences, 200030 Shanghai, China
Eugenia Litzinger
Affiliation:
Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Emil-Fischer-Str. 31, D-97074 Würzburg, Germany Dr. Remeis Sternwarte & ECAP, Universität Erlangen-Nürnberg, Sternwartstrasse 7, D-96049 Bamberg, Germany
Rights & Permissions[Opens in a new window]

Abstract

HTML view is not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The Megamaser Cosmology Project (MCP) measures the Hubble Constant by determining geometric distances to circumnuclear 22 GHz H2O megamasers in galaxies at low redshift (z < 0.05) but well into the Hubble flow. In combination with the recent, exquisite observations of the Cosmic Microwave Background by WMAP and Planck, these measurements provide a direct test of the standard cosmological model and constrain the equation of state of dark energy. The MCP is a multi-year project that has recently completed observations and is currently working on final analysis. Based on distance measurements to the first four published megamasers in the sample, the MCP currently determines H0 = 69.3 ± 4.2 km s−1 Mpc−1. The project is finalizing analysis for five additional galaxies. When complete, we expect to achieve a ~4% measurement. Given the tension between the Planck prediction of H0 in the context of the standard cosmological model and astrophysical measurements based on standard candles, the MCP provides a critical and independent geometric measurement that does not rely on external calibrations or a distance ladder.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2018 

References

Alam, S., Ata, M., Bailey, S., et al. 2017, MNRAS, 470, 2617CrossRefGoogle Scholar
Bonvin, V., Coubin, F., Suyu, S., et al. 2017, MNRAS, 465, 4914CrossRefGoogle Scholar
Freedman, W. L., Madore, B. F., Gobson, B. K., et al. 2012, ApJ, 758, 24CrossRefGoogle Scholar
Gao, F., Braatz, J. A., Reid, M. J., et al. 2016, ApJ, 817, 128CrossRefGoogle Scholar
Humphreys, E. M. L., Reid, M. J., Moran, J. M., et al. 2013, ApJ, 775, 13CrossRefGoogle Scholar
Kuo, C. Y., Braatz, J. A., Reid, M. J., et al. 2013, ApJ, 767, 155CrossRefGoogle Scholar
Kuo, C. Y., Braatz, J. A., Lo, K. Y., et al. 2015, ApJ, 800, 26CrossRefGoogle Scholar
Planck Collaboration, Ade, P. A. R., Aghanim, N., et al. 2016, A&A, 594, 13Google Scholar
Reid, M. J., Braatz, J. A., Condon, J. J., et al. 2013, ApJ, 767, 154CrossRefGoogle Scholar
Riess, A. G., Macri, L. M., Hoffmann, S. L., et al. 2016, ApJ, 826, 56CrossRefGoogle Scholar
You have Access
2
Cited by

Send article to Kindle

To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

A Measurement of the Hubble Constant by the Megamaser Cosmology Project
Available formats
×

Send article to Dropbox

To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

A Measurement of the Hubble Constant by the Megamaser Cosmology Project
Available formats
×

Send article to Google Drive

To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

A Measurement of the Hubble Constant by the Megamaser Cosmology Project
Available formats
×
×

Reply to: Submit a response

Please enter your response.

Your details

Please enter a valid email address.

Conflicting interests

Do you have any conflicting interests? *