Site Map
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

Two-dimensional multi-component photometric decomposition of CALIFA galaxies

J. Méndez-Abreu, T. Ruiz-Lara, L. Sánchez-Menguiano, A. de Lorenzo-Cáceres, L. Costantin, C. Catalán-Torrecilla, E. Florido, J. A. L. Aguerri, J. Bland-Hawthorn, E. M. Corsini, R.-J. Dettmar, L. Galbany, R. García-Benito, R. A. Marino, I. Márquez, R. A. Ortega-Minakata, P. Papaderos, S. F. Sánchez, P. Sánchez-Blázquez, K. Spekkens, G. van de Ven, V. Wild, B. Ziegler

We present a two-dimensional multi-component photometric decomposition of 404 galaxies from the CALIFA Data Release 3. They represent all possible galaxies with no clear signs of interaction and not strongly inclined in the final CALIFA data release. Galaxies are modelled in the g, r, and i SDSS images including, when appropriate, a nuclear point source, bulge, bar, and an exponential or broken disc component. We use a human-supervised approach to determine the optimal number of structures to be included in the fit. The dataset, including the photometric parameters of the CALIFA sample, is released together with statistical errors and a visual analysis of the quality of each fit. The analysis of the photometric components reveals a clear segregation of the structural composition of galaxies with stellar mass. At high masses (log(Mstar/Msun)〉11), the galaxy population is dominated by galaxies modelled with a single Sersic or a bulge+disc with a bulge-to-total (B/T) luminosity ratio B/T〉0.2. At intermediate masses (9.5〈log(Mstar/Msun)〈11), galaxies described with bulge+disc but B/T 〈 0.2 are preponderant, whereas, at the low mass end (log(Mstar/Msun)〈9.5), the prevailing population is constituted by galaxies modelled with either pure discs or nuclear point sources+discs (i.e., no discernible bulge). We obtain that 57% of the volume corrected sample of disc galaxies in the CALIFA sample host a bar. This bar fraction shows a significant drop with increasing galaxy mass in the range 9.5〈log(Mstar/Msun)〈11.5. The analyses of the extended multi-component radial profile result in a volume-corrected distribution of 62%, 28%, and 10% for the so-called Type I, Type II, and Type III disc profiles, respectively. These fractions are in discordance with previous findings. We argue that the different methodologies used to detect the breaks are the main cause for these differences.

Astronomy and Astrophysics (Submitted)

>> PDF

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website