A stringent test of the galaxy formation paradigm: detailed modeling of the dynamics and stellar population of the Milky Way
Lead Research Organisation:
University of Oxford
Department Name: Oxford Physics
Abstract
High and low-redshift observations, in combination with numerical simulations, have provided a scenario, over the last 30 years, in which galaxy formation proceeds in a hierarchical fashion, driven by the gravitational collapse of dark matter (DM). Although the scenario explains most of the observations, its strongest and cleanest predictions still have to be confirmed: (i) galaxies are expected to be embedded in massive DM halos, however, remarkably, the very existence of DM is still debated and the possibility that the laws of gravity are not those of Einstein is under discussion. (ii) the hierarchical build up of galaxies is expected to leave behind a very large number of substructures, in both the dark and luminous matter. Although some substructure in nearby galaxies exists, this is not at the expected level. (iii) galaxy formation models make detailed prediction about the age and chemical composition of galactic substructure, but these information are difficult to extract from galaxy observations. Due to its vicinity, our Milky Way constitute a unique laboratory to perform the above stringent observational tests of the galaxy formation paradigm. For our Galaxy in fact individual stars can be easily observed, and position and velocity can in principle be obtained. The stars could be used as tracers of the gravity to accurately detect the presence of DM. The chemical composition of individual stars can also be measured, and could be used, in combination with the stellar kinematics, to uncover stellar subcomponents in the Galaxy. However until now no such data existed. The situation is soon going to change dramatically. A number of ongoing large observational survey from the ground (RAVE, SEGUE) and from space (Gaia) will measure position and velocities for a large fraction of all the stars in our Galaxy. This will provide the biggest improvement in our knowledge of the Galaxy, since Galileo observed it with its telescope, four centuries ago, first realizing that it was actually made of individual stars. The new data have a similar potential to revolutionize our understanding of how galaxies form. The main goal of my proposed project is to perform the above three stringent tests of the galaxy formation paradigm, by constructing a detailed model of the dynamics and the chemical composition of our Milky Way, to be compared with the position, velocity and chemical composition stellar measurements provided by the RAVE, SEGUE and then Gaia survey.
Organisations
- University of Oxford (Fellow, Lead Research Organisation)
- Leiden University (Collaboration)
- European Southern Observatory (ESO) (Collaboration)
- ASTRON Netherlands Institute for Radio Astronomy (Collaboration)
- University of Groningen (Collaboration)
- University of Hertfordshire (Collaboration)
- New Mexico Institute of Mining and Technology (Collaboration)
- University of California, Berkeley (Collaboration)
- Paris Diderot University (Collaboration)
- Max Planck Society (Collaboration)
- Claude Bernard University Lyon 1 (UCBL) (Collaboration)
- University of Toronto (Collaboration)
- Gemini Observatory (Collaboration)
People |
ORCID iD |
| Michele Cappellari (Principal Investigator / Fellow) |
Publications
Alatalo K
(2011)
DISCOVERY OF AN ACTIVE GALACTIC NUCLEUS DRIVEN MOLECULAR OUTFLOW IN THE LOCAL EARLY-TYPE GALAXY NGC 1266
in The Astrophysical Journal
Bois M
(2010)
Formation of slowly rotating early-type galaxies via major mergers: a resolution study Formation of slowly rotating early-type galaxies
in Monthly Notices of the Royal Astronomical Society
Bureau M
(2011)
The SAURON project - XVIII. The integrated UV-line-strength relations of early-type galaxies The SAURON project - XVIII
in Monthly Notices of the Royal Astronomical Society
Cappellari M
(2009)
The mass of the black hole in Centaurus A from SINFONI AO-assisted integral-field observations of stellar kinematics
in Monthly Notices of the Royal Astronomical Society
Cappellari M
(2007)
The SAURON project - X. The orbital anisotropy of elliptical and lenticular galaxies: revisiting the (V/ , ) diagram with integral-field stellar kinematics
in Monthly Notices of the Royal Astronomical Society
Cappellari M
(2011)
The ATLAS3D project - VII. A new look at the morphology of nearby galaxies: the kinematic morphology-density relation The ATLAS3D project - VII. Morphology-density
in Monthly Notices of the Royal Astronomical Society
Cappellari M
(2008)
Measuring the inclination and mass-to-light ratio of axisymmetric galaxies via anisotropic Jeans models of stellar kinematics
in Monthly Notices of the Royal Astronomical Society
Cappellari M
(2011)
The ATLAS3D project - I. A volume-limited sample of 260 nearby early-type galaxies: science goals and selection criteria The ATLAS3D project - I. The sample
in Monthly Notices of the Royal Astronomical Society
Cappellari M
(2009)
DYNAMICAL MASSES OF EARLY-TYPE GALAXIES AT z ~ 2: ARE THEY TRULY SUPERDENSE?
in The Astrophysical Journal
Davis T
(2011)
The ATLAS3D project - V. The CO Tully-Fisher relation of early-type galaxies The CO-TFR of early-type galaxies
in Monthly Notices of the Royal Astronomical Society
Emsellem E
(2011)
The ATLAS3D project - III. A census of the stellar angular momentum within the effective radius of early-type galaxies: unveiling the distribution of fast and slow rotators Census of the stellar angular momentum in ETGs
in Monthly Notices of the Royal Astronomical Society
Emsellem E
(2007)
The SAURON project - IX. A kinematic classification for early-type galaxies
in Monthly Notices of the Royal Astronomical Society
Falcón-Barroso J
(2011)
The SAURON project - XIX. Optical and near-infrared scaling relations of nearby elliptical, lenticular and Sa galaxies The SAURON project - XIX
in Monthly Notices of the Royal Astronomical Society
Ganda K
(2007)
Absorption-line strengths of 18 late-type spiral galaxies observed with SAURON
in Monthly Notices of the Royal Astronomical Society
Jeong H
(2009)
The SAURON project - XIII. SAURON-GALEX study of early-type galaxies: the ultraviolet colour-magnitude relations and Fundamental Planes
in Monthly Notices of the Royal Astronomical Society
Jesseit R
(2009)
Specific angular momentum of disc merger remnants and the ? R -parameter
in Monthly Notices of the Royal Astronomical Society
Khochfar S
(2011)
The ATLAS3D project - VIII. Modelling the formation and evolution of fast and slow rotator early-type galaxies within ?CDM Fast and slow rotators
in Monthly Notices of the Royal Astronomical Society
Krajnovi?? D
(2009)
Determination of masses of the central black holes in NGC 524 and 2549 using laser guide star adaptive optics
in Monthly Notices of the Royal Astronomical Society
Krajnovic D
(2011)
The ATLAS3D project - II. Morphologies, kinemetric features and alignment between photometric and kinematic axes of early-type galaxies Morphologies, kinematics and alignment
in Monthly Notices of the Royal Astronomical Society
Krajnovic D
(2008)
The SAURON project - XII. Kinematic substructures in early-type galaxies: evidence for discs in fast rotators
in Monthly Notices of the Royal Astronomical Society
Kuntschner H
(2010)
The SAURON project - XVII. Stellar population analysis of the absorption line strength maps of 48 early-type galaxies The SAURON project - XVII
in Monthly Notices of the Royal Astronomical Society
McDermid R
(2007)
Connecting stars and ionised gas with integral-field spectroscopy
in New Astronomy Reviews
Neumayer N
(2007)
The Central Parsecs of Centaurus A: High-excitation Gas, a Molecular Disk, and the Mass of the Black Hole
in The Astrophysical Journal
Onodera M
(2010)
A z = 1.82 ANALOG OF LOCAL ULTRA-MASSIVE ELLIPTICAL GALAXIES
in The Astrophysical Journal
Oosterloo T
(2007)
The kinematics and morphology of the Hi in gas-poor galaxies
in New Astronomy Reviews
Oosterloo T
(2010)
Early-type galaxies in different environments: an H i view Early-type galaxies in different environments
in Monthly Notices of the Royal Astronomical Society
Peletier R
(2007)
The SAURON project - XI. Stellar populations from absorption-line strength maps of 24 early-type spirals
in Monthly Notices of the Royal Astronomical Society
Prichard L
(2017)
The KMOS Cluster Survey (KCS). III. Fundamental Plane of Cluster Galaxies at z ? 1.80 in JKCS 041
in The Astrophysical Journal
Sarzi M
(2010)
The SAURON project - XVI. On the sources of ionization for the gas in elliptical and lenticular galaxies
in Monthly Notices of the Royal Astronomical Society
Sarzi M
(2007)
On the origin and fate of ionised-gas in early-type galaxies: The SAURON perspective
in New Astronomy Reviews
Sarzi M
(2011)
The planetary nebulae population in the central regions of M32: the SAURON view PNe in the central regions of M32
in Monthly Notices of the Royal Astronomical Society
Scott N
(2009)
The SAURON Project - XIV. No escape from V esc : a global and local parameter in early-type galaxy evolution
in Monthly Notices of the Royal Astronomical Society
Seth A
(2010)
THE NGC 404 NUCLEUS: STAR CLUSTER AND POSSIBLE INTERMEDIATE-MASS BLACK HOLE
in The Astrophysical Journal
Shapiro K
(2010)
The SAURON project - XV. Modes of star formation in early-type galaxies and the evolution of the red sequence
in Monthly Notices of the Royal Astronomical Society
Van De Ven G
(2010)
THE EINSTEIN CROSS: CONSTRAINT ON DARK MATTER FROM STELLAR DYNAMICS AND GRAVITATIONAL LENSING
in The Astrophysical Journal
Van Den Bosch R
(2008)
Triaxial orbit based galaxy models with an application to the (apparent) decoupled core galaxy NGC 4365
in Monthly Notices of the Royal Astronomical Society
Weijmans A
(2009)
Stellar velocity profiles and line strengths out to four effective radii in the early-type galaxies NGC 3379 and 821
in Monthly Notices of the Royal Astronomical Society
Williams M
(2009)
Kinematic constraints on the stellar and dark matter content of spiral and S0 galaxies Stellar and dark matter in disc galaxies
in Monthly Notices of the Royal Astronomical Society
Williams M
(2010)
The Tully-Fisher relations of early-type spiral and S0 galaxies Tully-Fisher relations of early-type discs
in Monthly Notices of the Royal Astronomical Society
Young L
(2008)
Structure and Kinematics of Molecular Disks in Fast-Rotator Early-Type Galaxies
in The Astrophysical Journal
Young L
(2011)
The ATLAS3D project - IV. The molecular gas content of early-type galaxies? Molecular gas content of early-type galaxies
in Monthly Notices of the Royal Astronomical Society
| Description | Since Edwin Hubble introduced his famous tuning fork diagram more than 70 years ago, spiral galaxies and early-type galaxies have been regarded as being two distinct families. The spirals are characterized by the presence of disks of stars and gas in rapid rotation, while the early-types are gas poor and described as spheroidal systems, with less rotation and often non-axisymmetric shapes. This clear distinction is emphasized in Hubble's tuning-fork diagram, where early-type galaxies (E0-E7 and S0) lie on the handle of the fork, well separated from spiral galaxies (Sa-Sc). The separation is physically relevant as it implies a distinct path of formation for the two classes of objects. A known issue of Hubble's classification, however, is that it mostly relies on optical images, from which it is nearly impossible to recognize thin face-on disks of stars from much rounder edge-on spheroids. For this reason the fraction of disks-like systems hidden in the early-type category has been a matter of debate for decades. The solution to the problem comes from observations of the stellar kinematics: the stars in a thin disk rotate much faster than those in a rounder spheroid. This implies that the kinematics makes it possible to recognize a disk from a spheroid at any inclination. However it requires complex and time-consuming observations. To address this question I put together as Co-PI a team of people we called Atlas3D. Thanks to the major allocation of 40 nights of observations with the SAURON integral-field spectrograph at the William Herschel Telescope, the team derived maps of the stellar motions for all 260 galaxies in a carefully selected volume of the nearby Universe. The results were unexpected and reveal a new paradigm for early-type galaxies. For the first time, it was found that the overwhelming majority of the early-type galaxies in the nearby Universe does not consist of roundish spheroidal objects, but instead has disks and mostly resembles spiral galaxies with the gas and dust removed. Only a tiny fraction of the early-type galaxies - the "slow rotators" - are genuine spheroids. This indicates that Hubble's classic tuning-fork gives a misleading description of galaxy structure. To correct for this fact the team proposed a revised scheme in which the vast majority of early-type galaxies - termed "fast-rotators" - are close relatives of spiral galaxies (Sa-Sc) and for this reason form a parallel sequence to them. The new paradigm highlights a much closer connection between early-type and spiral galaxies than previously thought, and this will need to be considered in future models of how galaxies form. |
| Exploitation Route | Our finding is becoming central to the understanding of galaxy formation. It has contributed to the development of much larger surveys of galaxies using two-dimensional observations of the stellar motions, to be able to recognize how galaxy structure varies as a function of environment and other galaxy properties. |
| Sectors | Aerospace, Defence and Marine,Education,Culture, Heritage, Museums and Collections,Other |
| URL | http://www.skyandtelescope.com/astronomy-news/rethinking-galaxies/ |
| Description | For millennia humanity has aspired at understanding our place and origins in the Universe. Less than a century ago, we discovered we live in a galaxy like millions of others populating the Universe. For this reason, today finding our origins means studying how galaxies came into existence. My research tries to address the question about our origins. |
| First Year Of Impact | 2010 |
| Sector | Aerospace, Defence and Marine,Education,Other |
| Impact Types | Cultural |
| Description | Astrophysics at Oxford: 2010-2015 |
| Amount | £2,486,342 (GBP) |
| Funding ID | ST/H002456/1 |
| Organisation | Science and Technologies Facilities Council (STFC) |
| Sector | Public |
| Country | United Kingdom |
| Start | 04/2010 |
| End | 03/2015 |
| Description | Atlas3D Project |
| Organisation | ASTRON Netherlands Institute for Radio Astronomy |
| Country | Netherlands |
| Sector | Private |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | Claude Bernard University Lyon 1 (UCBL) |
| Department | Astrophysics Research Centre of Lyon (CRAL) |
| Country | France |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | European Southern Observatory (ESO) |
| Country | Germany |
| Sector | Charity/Non Profit |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | Gemini Observatory |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | Leiden University |
| Department | Leiden Observatory |
| Country | Netherlands |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | Max Planck Society |
| Department | Max Planck Institute For Extraterrestrial Physics (MPE) |
| Country | Germany |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | Max Planck Society |
| Department | Max Planck Institute for Astrophysics |
| Country | Germany |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | New Mexico Institute of Mining and Technology |
| Department | Physics Department |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | Paris Diderot University |
| Country | France |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | University of California, Berkeley |
| Department | Department of Astronomy |
| Country | United States |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | University of Groningen |
| Department | Kapteyn Astronomical Institute |
| Country | Netherlands |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | University of Hertfordshire |
| Department | Centre for Astrophysics Research (CAR) |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Atlas3D Project |
| Organisation | University of Toronto |
| Department | Dunlap Institute for Astronomy & Astrophysics |
| Country | Canada |
| Sector | Academic/University |
| PI Contribution | http://www-astro.physics.ox.ac.uk/atlas3d/ |
| Collaborator Contribution | The collaborators have contributed to the science results |
| Impact | As part of this effort we were awarded major observing proposals at various multi-wavelength facilities (WSRT, IRAM 30-m, CARMA, INT, WHT). We submitted 12 refereed papers, of which 8 are already published or in press. |
| Start Year | 2007 |
| Description | Press release |
| Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
| Part Of Official Scheme? | No |
| Primary Audience | Public/other audiences |
| Results and Impact | Press releases of the results were published by the University of Oxford UK, the CNRS in France and the Subaru Telescopes in Japan. The results were later disseminated by about 10 additional popular scientific journals on the web. |
| Year(s) Of Engagement Activity | 2010 |