Durham University's Citation Achievements in Space Science
Institutional Feature, March 2011
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So 2dF gave us a 3D map of a section of the local universe. This led to a step change in terms of our understanding of large-scale structure in the universe. With these data we carried out statistical analyses to analyze not just the present state of the universe but also its evolution.
How does this relate to understanding the origin of large-scale structure such as clusters of galaxies?
It turns out that the pattern of galaxy clustering encodes information from the Big Bang. We know most of the matter is dark, but we don't know exactly what that is. A major breakthrough of 2dF was the analysis that allowed us to relate the measurement of the clustering of galaxies in the present-day universe to the universe in the early stages of the Big Bang.
The reason why cosmology has been such a boom area of physics is because in the 1980s theories were advanced for how the universe was seeded with small irregularities that would later grow into the structures we see today. The universe had a rapid period of exponential expansion in which tiny cracks appeared and these became the source of structure. Inflation provided a prescription for how the universe was prepared. 2dF, in combination with simulations of the growth of cosmic structure, tested cold dark matter (CDM) cosmologies against actual data.
How do the 2dF findings relate to the microwave background?
The microwave background is the relic radiation from the Big Bang. From our statistics of the galaxy distribution we determined the nature of the perturbations in the universe and thus linked, for the first time, the early universe to the present universe in a very direct manner.
A quirky aspect of the relationship between the very early universe and today's universe is a subtle phenomenon called baryonic acoustic oscillations. What were you able to say about them?
Simulation showing a Milky Way-like galaxy around five billion years ago
when most satellite galaxy collisions were happening. Figure credit: Andrew
Cooper/John Helly, Durham University.
View/Download six images & complete descriptions
from Durham University..
The position of those oscillations depends on another big component of the universe, dark energy, which plays a secondary role in the formation of galaxies. Early in 2005, the 2dF and SDSS teams put out a joint press release announcing the discovery of the baryonic acoustic oscillations. Our paper on the power spectrum analysis of the final data set ranks ninth on our list of Highly Cited Papers (Cole S, et al., "The 2dF Galaxy Redshift Survey: power-spectrum analysis of the final data set and cosmological implications," Mon. Notic. Roy. Astron. Soc. 362[2]: 505-34, 11 September 2005).
Strictly speaking, 2dF got there first; the joint press release perhaps gave the community the incorrect impression of a dead heat. It's true that SDSS has been a tremendous success and of course it was a larger project than 2dF. But as this analysis of space science papers from Durham demonstrates, 2dF had a huge impact and was first past the post on several occasions.
Let me invite you to summarize the 2dF survey and Durham's main contributions to it.
We had three major achievements. These are the catalog itself, embodied in the paper at #2 on your list, where we published the data very early to benefit the community (Colless M, et al., "The 2dF Galaxy Redshift Survey: spectra and redshifts," Mon. Notic. Roy. Astron. Soc. 328[4]: 1039-63, 21 December 2001); secondly the power spectrum analysis paper #9; and thirdly, the paper #12 on the near-infrared galaxy luminosity functions.
This paper, "The 2dF Galaxy Redshift Survey: near-infrared galaxy luminosity functions" (Cole S, et al., Mon, Notic. Roy. Astron. Soc. 326[1]: 255-73, 1 September 2001), was done by combining the redshifts measured in 2dF with an infrared photometric survey (known as 2MASS). The amount of infrared light directly correlates with the numbers of stars in galaxies, so #12 addresses questions such as how many stars do different types of galaxies contain. The survey was a triumph of British ingenuity, where major discoveries were made despite working with a shoestring budget!
Finally Professor Frenk, what can you add about the topic of hierarchical galaxy formation?
Our highly cited papers other than 2dF are theory papers; several of these use the Millennium Simulation carried out by the Virgo consortium. This comprises a core group of about a dozen scientists, with the major hubs being the ICC at Durham and the Max Planck Institute for Astrophysics in Garching, Germany. There are about 400 published papers based on this simulation.
Two of the highly cited ones are the June 2005 Nature paper ranked at #3 (Springel V, et al., "Simulations of the formation, evolution and clustering of galaxies and quasars," 435[7042]: 629-36) and the aforementioned paper ranked at #6, and both are concerned with hierarchical galaxy formation. These are efforts to build onto the background of the dark matter evolution the physical theories that describe the way in which galaxies like the Milky Way form.
One of the things we helped discover is that supermassive black holes play a key role in the buildup of galaxies, which is #11 on the list (Bower G, et al., "Breaking the hierarchy of galaxy formation," Mon. Notic. Roy. Astron. Soc. 370[2]: 645-55, 1 August 2006). Paper #3 has a big following because it put forward ideas that are now widely accepted about why galaxies have the appearance they do.
Professor Carlos Frenk, FRS, and Professor Ray Sharples
Institute for Computational Cosmology and Centre for Advanced
Instrumentation
Department of Physics
Durham University
Durham, United Kingdom
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DURHAM UNIVERSITY'S MOST CURRENT MOST-CITED PAPER IN ESSENTIAL SCIENCE INDICATORS:
Tremaine S, et al., "The slope of the black hole mass versus velocity dispersion correlation," Astrophys. J. 574(2): 740-53, Part 1, 1 August 2002 with 885 cites. Source: Essential Science Indicators from Clarivate.
KEYWORDS: COSMOLOGY, BIG BANG, OBSERVATIONAL EXTRAGALACTIC ASTRONOMY, THEORETICAL ASTROPHYSICS, INSTRUMENTATION, OBSERVATION, THEORY, TEAMWORK, GALAXY FORMATION, TWO DEGREE FIELD GALAXY REDSHIFT SURVEY, 2dFGRS, QUASAR REDSHIFTS, ANGLO-AUSTRALIAN TELESCOPE, DATA ANALYSIS, COSMOLOGICAL SIMULATIONS, GALAXY CLUSTERING PATTERN, MICROWAVE BACKGROUND, BARYONIC ACOUSTIC OSCILLATIONS, POWER SPECTRUM ANALYSIS, NEAR INFRARED GALAXY LUMINOSITY FUNCTIONS, MILLENNIUM SIMULATION, VIRGO CONSORTIUM.
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