A SINFONI view of the nuclear activity and circum-nuclear star formation in NGC4303

Natacha Z. Dametto, Rogério Riffel, Luis Colina, Rogemar Riffel, Javier Piqueras López, Richard Davies, Leonard Burtscher, Roberto Menezes, Santiago Arribas, Miriani Pastoriza, Alvaro Labiano, Thaisa Storchi-Bergmann, Luis Dahmer-Hahn, Dinalva Sales. 2018. A SINFONI view of the nuclear activity and circum-nuclear star formation in NGC4303 (vol 461, pg 4192, 2016). Monthly Notices of the Royal Astronomical Society 478, 4, 4641-4641 DOI: 10.1093/mnras/sty1560

We present a spatially resolved stellar population study of the inner ∼200\,pc radius of NGC4303 based on near-infrared integral field spectroscopy with SINFONI/VLT at a spatial resolution of 40-80pc and using the STARLIGHT code. We found the distribution of the stellar populations presents a spatial variation, suggesting an age stratification. Three main structures stand out. Two nuclear blobs, one composed by young stars (t ≤ 50Myr) and one with intermediate-age stars (50Myr < t ≤ 2Gyr) both shifted from the centre. The third one is an internal intermediate-age spiral arm-like structure, surrounding the blob of young stars. Our results indicate star formation has occurred through multiple bursts in this source. Furthermore, the youngest stellar populations (t ≲ 2Gyr) are distributed along a circumnuclear star-forming ring with r∼250pc. The ring displays star formation rates (SFRs) in the range of 0.002-0.14M⊙yr−1, favoring the `pearls-on-a-string’ scenario. The old underlying bulge stellar population component (t > 2Gyr) is distributed outside the two blob structures. For the nuclear region (inner ∼60pc radius) we derived a SFR of 0.43\,M⊙yr−1 and found no signatures of non-thermal featureless continuum and hot dust emission, supporting the scenario in which a LLAGN/LINER-like source is hidden in the centre of NGC4303. Thus, our results reveal a rather complex star formation history in NGC4303, with different stellar population components coexisting with a low efficiency accreting black hole in its centre.

Otras publicaciones