Galaxy and mass assembly (GAMA) : The wavelength-dependent sizes and profiles of galaxies revealed by MegaMorph
View/ Open
Author
Vulcani, Benedetta
Bamford, Steven P.
Häußler, Boris
Vika, Marina
Rojas, Alex L.
Agius, Nicola K.
Baldry, Ivan K.
Bauer, Amanda E.
Brown, Michael J. I.
Driver, Simon
Graham, Alister W.
Kelvin, Lee S.
Liske, Jochen
Loveday, Jon
Popescu, Cristina C.
Robotham, Aaron S. G.
Tuffs, Richard J.
Attention
2299/16424
Abstract
We investigate the relationship between colour and structure within galaxies using a large, volume-limited sample of bright, low-redshift galaxies with optical-near-infrared imaging from the Galaxy AndMass Assembly survey.We fit single-component,wavelength-dependent, elliptical Sérsic models to all passbands simultaneously, using software developed by the MegaMorph project. Dividing our sample by n and colour, the recovered wavelength variations in effective radius (Re) and Sérsic index (n) reveal the internal structure, and hence formation history, of different types of galaxies. All these trends depend on n; some have an additional dependence on galaxy colour. Late-type galaxies (nr < 2.5) show a dramatic increase in Sérsic index with wavelength. This might be a result of their two-component (bulge-disc) nature, though stellar population gradients within each component and dust attenuation are likely to play a role. All galaxies show a substantial decrease in Re with wavelength. This is strongest for early types (nr > 2.5), even though they maintain constant n with wavelength, revealing that ellipticals are a superimposition of different stellar populations associated with multiple collapse and merging events. Processes leading to structures with larger Re must be associated with lower metallicity or younger stellar populations. This appears to rule out the formation of young cores through dissipative gas accretion as an important mechanism in the recent lives of luminous elliptical galaxies.
Publication date
2014-06-21Published in
Monthly Notices of the Royal Astronomical SocietyPublished version
https://doi.org/10.1093/mnras/stu632Other links
http://hdl.handle.net/2299/16424Metadata
Show full item recordRelated items
Showing items related by title, author, creator and subject.
-
The H alpha galaxy survey. I. The galaxy sample, H alpha narrow-band observations and star formation parameters for 334 galaxies
James, P.A.; Shane, N.S.; Beckman, J.E.; Cardwell, A.; Collins, C.A.; Etherton, J.; de Jong, R.S.; Fathi, K.; Knapen, J.; Peletier, R.F.; Percival, S.M.; Pollacco, D.L.; Seigar, M.S.; Stedman, S. (2004)We discuss the selection and observations of a large sample of nearby galaxies, which we are using to quantify the star formation activity in the local Universe. The sample consists of 334 galaxies across all Hubble types ... -
On the Key Processes that Drive Galaxy Evolution: the Role of Galaxy Mergers, Accretion, Local Environment and Feedback in Shaping the Present-Day Universe
Martin, Garreth (2019-07-17)The study of galaxy evolution is a fundamental discipline in modern astrophysics, dealing with how and why galaxies of all types evolve over time. The diversity of present-day galaxies is a reflection of the processes ... -
Galaxy pairs in the SDSS - XIII. The connection between enhanced star formation and molecular gas properties in galaxy mergers.
Violino, Giulio; Ellison, S.L.; Sargent, M.; Coppin, Kristen; Scudder, Jillian; Mendel, Trevor; Saintonge, A. (2018-05-11)We investigate the connection between star formation and molecular gas properties in galaxy mergers at low redshift (z ≤ 0.06). The study we present is based on IRAM 30-m CO(1-0) observations of 11 galaxies with a close ...