From The University of Hawai’i-Manoa Institute for Astronomy : “UH astronomers map distances to 56000 galaxies – largest-ever catalog University of Hawaiʻi at Mānoa” 

From The University of Hawai’i-Manoa Institute for Astronomy

9.25.22
Roy Gal
roygal@hawaii.edu
(808) 388-8690

1
Full-sky map showing Cosmicflows-4’s 56,000 galaxies with distance measurements.

How old is our universe, and what is its size? A team of researchers led by University of Hawaiʻi at Mānoa astronomers Brent Tully and Ehsan Kourkchi from the Institute for Astronomy have assembled the largest-ever compilation of high-precision galaxy distances, called Cosmicflows-4. Using eight different methods, they measured the distances to a whopping 56,000 galaxies. The study has been published in The Astrophysical Journal [below].

Galaxies, such as the Milky Way, are the building blocks of the universe, each comprised of up to several hundred billion stars. Galaxies beyond our immediate neighborhood are rushing away, faster if they are more distant, which is a consequence of the expansion of the universe that began at the moment of the Big Bang. Measurements of the distances of galaxies, coupled with information about their velocities away from us, determine the scale of the universe and the time that has elapsed since its birth.

“Since galaxies were identified as separate from the Milky Way a hundred years ago, astronomers have been trying to measure their distances,” said Tully. “Now by combining our more accurate and abundant tools, we are able to measure distances of galaxies, and the related expansion rate of the universe and the time since the universe was born with a precision of a few percent.”

From the newly published measurements, the researchers derived the expansion rate of the universe, called the Hubble Constant, or H0. The team’s study gives a value of H0=75 kilometers per second per megaparsec or Mpc (1 megaparsec = 3.26 million light years), with very small statistical uncertainty of about 1.5%.

There are a number of ways to measure galaxy distances. Generally, individual researchers focus on an individual method. The Cosmicflows program spearheaded by Tully and Kourkchi includes their own original material from two methods, and additionally incorporates information from many previous studies. Because Cosmicflows-4 includes distances derived from a variety of independent, distinct distance estimators, intercomparisons should mitigate against a large systematic error.

Science paper:
The Astrophysical Journal

See the full article here .


five-ways-keep-your-child-safe-school-shootings

Please help promote STEM in your local schools.

Stem Education Coalition

The The University of Hawai’i Institute for Astronomy is a research unit within the University of Hawai’i system. Institute for Astronomy’s main headquarters are located at 2680 Woodlawn Drive in Honolulu, Hawai’i, adjacent to the University of Hawai’i-Mānoa campus. Additional facilities are located at Pukalani, Maui and Hilo on Hawaiʻi island (the Big Island). Institute for Astronomy employs over 150 astronomers and support staff. Institute for Astronomy astronomers perform research into Solar System objects, stars, galaxies and cosmology.
The Institute for Astronomy was founded in 1967 to conduct research and to manage the observatory complexes at Haleakalā, Maui and the Mauna Kea Observatory on the summit of Mauna Kea. It has approximately 55 faculty and employs over 300 people.

From University of Hawai’i-Manoa

University of Hawaii 2.2 meter telescope, Mauna Kea, Hawai’i

The W. M. Keck Observatory operates the largest, most scientifically productive telescopes on Earth.

The two, 10-meter optical/infrared telescopes near the summit of Mauna Kea on the island of Hawai’i feature a suite of advanced instruments including imagers, multi-object spectrographs, high-resolution spectrographs, integral-field spectrographs and world-leading laser guide star adaptive optics systems.

System Overview

The The University of Hawai‘i includes 10 campuses and dozens of educational, training and research centers across the Hawaiian Islands. As the public system of higher education in Hawai‘i, The University of Hawai‘i offers opportunities as unique and diverse as our Island home.

The 10 University of Hawai‘i campuses and educational centers on six Hawai’ian Islands provide unique opportunities for both learning and recreation.

The University of Hawai‘i is the State’s leading engine for economic growth and diversification, stimulating the local economy with jobs, research and skilled workers.

The University of Hawaiʻi system, formally The University of Hawaiʻi is a public college and university system that confers associate, bachelor’s, master’s, and doctoral degrees through three university campuses, seven community college campuses, an employment training center, three university centers, four education centers and various other research facilities distributed across six islands throughout the state of Hawaii in the United States. All schools of The University of Hawaiʻi system are accredited by the Western Association of Schools and Colleges. The University of Hawai‘i system’s main administrative offices are located on the property of the University of Hawaiʻi-Mānoa in Honolulu CDP.

The University of Hawaiʻi-Mānoa is the flagship institution of The University of Hawaiʻi system. It was founded as a land-grant college under the terms of the Morrill Acts of 1862 and 1890. Programs include Hawaiian/Pacific Studies, Astronomy, East Asian Languages and Literature, Asian Studies, Comparative Philosophy, Marine Science, Second Language Studies, along with Botany, Engineering, Ethnomusicology, Geophysics, Law, Business, Linguistics, Mathematics, and Medicine. The second-largest institution is The University of Hawaiʻi at Hilo on the “Big Island” of Hawaiʻi, with over 3,000 students. The University of Hawaiʻi-West Oʻahu in Kapolei primarily serves students who reside in Honolulu’s western and central suburban communities. The University of Hawaiʻi Community College system comprises four community colleges island campuses on O’ahu and one each on Maui, Kauaʻi, and Hawaiʻi. The schools were created to improve accessibility of courses to more Hawaiʻi residents and provide an affordable means of easing the transition from secondary school/high school to college for many students. The University of Hawaiʻi education centers are located in more remote areas of the State and its several islands, supporting rural communities via distance education.

Research facilities

Center for Philippine Studies
Cancer Research Center of Hawaiʻi
East-West Center
Haleakalā Observatory
Hawaiʻi Natural Energy Institute
Institute for Astronomy
Institute of Geophysics and Planetology
Institute of Marine Biology
Lyon Arboretum
Mauna Kea Observatory
W. M. Keck Observatory
Waikīkī Aquarium