Astrophysics at Oxford: 2010-2015
Lead Research Organisation:
University of Oxford
Department Name: Oxford Physics
Abstract
Astrophysicists at Oxford are trying to determine six basic things about the Universe. (1) What is it made of? The Universe appears to be at the beginning of a period of accelerated expansion driven by some mysterious stuff known as 'dark energy'. Einstein had a theory for what this stuff is: he called it the Cosmological Constant. We will be testing his theory by measuring the apparent brightnesses of distant exploding stars (supernovae), by measuring the distortions of distant galaxies as light is bent by the gravity of more nearby galaxies, and by measuring the precise positions of about one million galaxies. (2) What is the history of Hydrogen in the Universe? Hydrogen - the most abundant element in the Universe - is the most important building material for making stars. Atoms of Hydrogen combine into molecules within dense clouds, and these clouds provide the nursery for the birth of new stars. We will be using giant new telescopes operating at millimetre and radio wavelengths to observe, and hence understand, this process throughout most of the history of the Universe. (3) What can we learn about how galaxies formed from galaxies observed at current times? We are involved in large observational programmes that can be viewed as 'archaeology' of nearby galaxies looking for clues of important events in their history, for example by finding fast-moving gas orbiting a dormant supermassive black hole. We also study the relation between stellar populations and dark matter by studying the orbits of stars within and beyond the optical light in a galaxy. (4) What can we learn about how galaxies formed from distant galaxies observed at earlier times? Because of the finite speed of light, distant galaxies are seen when the Universe, and the galaxies within it, were young, and often these galaxies are so dusty that they are only effectively studied using infrared and radio observations. We map out the large-scale distribution of galaxies in the distant Universe using a combination of wide-field imaging (taking pictures) and spectroscopy (spreading light out into its constituent colours). We study these systems as they form and evolve, sometimes in dramatic bursts of star formation associated with supermassive black holes. (5) When did the first galaxies form? The Hydrogen in the Universe formed atoms about 300,000 years after the Big Bang, but was largely re-ionized (converted back to protons and electrons) during the so-called Epoch of Reionization. We use giant ground-based telescopes and satellites (e.g. the Hubble Space Telescope) to study these first galaxies and determine whether it was radiation associated with the birth of these galaxies, or stars within them, that was responsible for the re-ionization. (6) How do black holes influence star and galaxy formation? Black holes grow by 'gobbling up' gas and stars in a process called accretion. This process seems commonly to yield outflows in the form of winds and jets, the latter capable of reaching speeds very close to the speed of light. We study these systems in our own galaxy and in distant galaxies to determine the physics of such 'feedback mechanisms' (growth of the black hole is halted, albeit temporarily, by outflows driven by processes associated with the black hole). Our aim is to understand the influence of (compact) black holes on the formation of stars, galaxies and clusters of galaxies on much large physical scales.
Organisations
- University of Oxford (Lead Research Organisation)
- UNIVERSITY OF EDINBURGH (Collaboration)
- Leiden University (Collaboration)
- California Institute of Technology (Collaboration)
- University of California, Los Angeles (UCLA) (Collaboration)
- UNIVERSITY OF BRITISH COLUMBIA (Collaboration)
- Paris Institute of Astrophysics (Collaboration)
Publications
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Mohamed S.
(2013)
The Link Between RS Ophiuchi and Type Ia Supernovae
in 18th European White Dwarf Workshop.
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Chen X.
(2014)
The sdB Mass - Orbital Period Relation for Long-Orbital-Period SdB+MS Binaries
in 6th Meeting on Hot Subdwarf Stars and Related Objects
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Bandyopadhyay Reba M.
(2010)
Hunting for Buried Treasure: Prospecting for a Population of Compact Objects in the Galactic Center
in AAS/High Energy Astrophysics Division #11
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Babuscia A
(2013)
Inflatable antenna for cubesats: Motivation for development and antenna design
in Acta Astronautica
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Bandyopadhyay Reba M.
(2010)
The Search for Buried Treasure: Near-IR Counterparts to Faint X-ray Sources in the Nuclear Bulge of the Milky Way
in American Astronomical Society Meeting Abstracts #215
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Fitzpatrick Benedict J. R.
(2010)
Simulating the Homunculus Nebula of Eta Carinae with an Innovative Multi-mass SPH Technique
in American Astronomical Society Meeting Abstracts #215
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Lin Jinrong
(2011)
Binary Evolution Leading to the Radio Pulsar PSR J1614-2230
in American Astronomical Society Meeting Abstracts #217
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Romanowsky Aaron J.
(2016)
The Dark Matter Conspiracy in Early-type Galaxies
in American Astronomical Society Meeting Abstracts #227
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Merrifield Michael
(2016)
Are Bulges and Disks Real? Decomposing Spectral Data Cubes Into Their Astrophysical Components
in American Astronomical Society Meeting Abstracts #227
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Matsumoto Jiro
(2013)
The Casimir effect as a candidate of dark energy
in arXiv e-prints
Description | Canada France Hawaii Telescope Lensing Survey (CFHTLenS) |
Organisation | Leiden University |
Department | Leiden Institute of Physics |
Country | Netherlands |
Sector | Academic/University |
PI Contribution | Miller was responsible for the shear measurements for this international collaboration, and took part in the cosmology analysis. |
Collaborator Contribution | Other aspects of the lensing analysis. |
Impact | Research publications |
Start Year | 2008 |
Description | Canada France Hawaii Telescope Lensing Survey (CFHTLenS) |
Organisation | University of British Columbia |
Country | Canada |
Sector | Academic/University |
PI Contribution | Miller was responsible for the shear measurements for this international collaboration, and took part in the cosmology analysis. |
Collaborator Contribution | Other aspects of the lensing analysis. |
Impact | Research publications |
Start Year | 2008 |
Description | Canada France Hawaii Telescope Lensing Survey (CFHTLenS) |
Organisation | University of Edinburgh |
Department | School of Physics and Astronomy |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Miller was responsible for the shear measurements for this international collaboration, and took part in the cosmology analysis. |
Collaborator Contribution | Other aspects of the lensing analysis. |
Impact | Research publications |
Start Year | 2008 |
Description | EarLy unIverse Exploration with nIRspec (ELIXIR) |
Organisation | Paris Institute of Astrophysics |
Country | France |
Sector | Academic/University |
PI Contribution | The Oxford network node has been analysing data from Hubble Space Telescope deep imaging fields (including those from the new WFC3 infrared camera) to determine observing strategies for JWST, and also to provide an initial target list for spectroscopy with NIRSpec on JWST. |
Collaborator Contribution | This is an EU FP7 network associated with the NIRSpec instrument on the James Webb Space Telescope. The Instrument Science Team comprises: Stephane Charlot (IAP, Paris - lead network); Andrew Bunker (Oxford); Marijn Franx (Leiden); Santiago Arribas (Madrid); Roberto Maiolino (Rome); Hans-Walter Rix (MPIA Heidelberg) and Peter Jakobsen (ESA), with out industrial partner (Astrium, Germany). We are responsible for the NIRSpec near-infrared spectrograph, which is being built and tested, and we will execute a 900-hour GTO programme to investigate galaxies at high redshift. The EU FP7 ELIXIR Network is intended to plan the science for this large programme. |
Impact | The Network funds several PhD students and Early Stage Researchers at the nodes across Europe, including two graduate students at Oxford (Joseph Caruana and Silvio Lorenzoni). These researchers have participated in many of the papers from our group, and Lorenzoni has a first-author paper accepted. |
Start Year | 2008 |
Description | Galaxies in the Reionization Epoch |
Organisation | California Institute of Technology |
Department | Caltech Astronomy |
Country | United States |
Sector | Academic/University |
PI Contribution | Oxford has been responsible for reducing the Hubble Space Telescope images and identifying potential high-redshift candidates through colour selection. |
Collaborator Contribution | Oxford has lead this project, in collaboration with Prof Richard Ellis at Caltech, using archival Hubble Space Telescope images with WFC3 to identify Lyman-break galaxies at z=7 and beyond. Caltech has mainly been involved in the spectroscopic follow-up. |
Impact | Five refereed accepted papers so far (Bunker et al. 2010; Wilkins et al. 2010; Lorenzoni et al. 2011; Wilkins et al. 2011, Wilkins et al. 2012). A press release in December 2009, resulting in extensive coverage. Several invited talks at conferences. |
Start Year | 2009 |
Description | Kilo Degree Survey weak lensing collaboration |
Organisation | Leiden University |
Department | Leiden Institute of Physics |
Country | Netherlands |
Sector | Academic/University |
PI Contribution | Responsible for the Point Spread Function modelling and weak lensing shear measurement, employed by the survey. Jointly responsible for cosmology analysis and paper writing. |
Collaborator Contribution | All other aspects of data collection, survey analysis and paper writing |
Impact | Research papers |
Start Year | 2011 |
Description | Kilo Degree Survey weak lensing collaboration |
Organisation | University of Edinburgh |
Department | School of Physics and Astronomy |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Responsible for the Point Spread Function modelling and weak lensing shear measurement, employed by the survey. Jointly responsible for cosmology analysis and paper writing. |
Collaborator Contribution | All other aspects of data collection, survey analysis and paper writing |
Impact | Research papers |
Start Year | 2011 |
Description | The WFC3 Spectroscopic Parallel (WISP) Survey |
Organisation | University of California, Los Angeles (UCLA) |
Department | Physics and Astronomy |
Country | United States |
Sector | Academic/University |
PI Contribution | Oxford is responsible for studying the star formation rates of these galaxies from their H-alpha line luminosities, and for constructing the line luminosity function at redshifts around one. |
Collaborator Contribution | The WISP collaboration, based at UCLA and also the Spitzer Science Center (in Caltech) and with collaborators elsewhere in the USA and Germany, is responsible for reducing the Hubble Space Telescope slitless grism spectroscopy to search for emission line objects at high redshift. Most of this reduction and cataloging occurs in Los Angeles. |
Impact | One refereed paper on the initial work - Atek et al. (2010) - and several more in preparation. Various presentations by the team at American Astronomical Society meetings. |
Start Year | 2008 |
Description | Press release on the first Hubble WFC3 Deep Infrared Images |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | We issued a press release on our work on 8 December 2009 entitled "Reinvigorated Hubble Space Telescope Reveals Most Distant Galaxies Yet". Our press release results in extensive coverage in the scientific media and the international press including: Nature Blog http://blogs.nature.com/news/thegreatbeyond/2009/12/ hubble_revisits_distant_haunt.html BBC News (online) http://news.bbc.co.uk/1/hi/sci/tech/8401374.stm We also appeared in The Times (print version) |
Year(s) Of Engagement Activity | 2009 |