Bibcode
Martínez-Paredes, M.; González-Martín, O.; HyeongHan, K.; Geier, S.; García-Bernete, I.; Ramos Almeida, C.; Alonso-Herrero, A.; Aretxaga, I.; Kim, M.; Sohn, B. W.; Masegosa, J.
Bibliographical reference
The Astrophysical Journal
Advertised on:
12
2021
Journal
Citations
5
Refereed citations
5
Description
To study the nuclear (≲1 kpc) dust of nearby (z < 0.1) quasi-stellar objects (QSOs), we obtained new near-infrared (NIR) high angular resolution (~0.″3) photometry in the H and Ks bands for 13 QSOs with available mid-infrared (MIR) high angular resolution spectroscopy (~7.5-13.5 μm). We find that in most QSOs, the NIR emission is unresolved. We subtract the contribution from the accretion disk, which decreases from NIR (~35%) to MIR (~2.4%). We also estimate these percentages assuming a bluer accretion disk and find that the contribution in the MIR is nearly seven times larger. We find that the majority of objects (64%, 9/13) are better fitted by the disk+wind H17 model, while others can be fitted by the smooth F06 (14%, 2/13), clumpy N08 (7%, 1/13), clumpy H10 (7%, 1/13), and two-phase media S16 (7%, 1/13) models. However, if we assume the bluer accretion disk, the models fit only 2/13 objects. We measured two NIR-to-MIR spectral indexes, α NIR-MIR(1.6-8.7 μm) and α NIR-MIR(2.2-8.7 μm), and two MIR spectral indexes, α MIR(7.8-9.8 μm) and α MIR(9.8-11.7 μm), from models and observations. From observations, we find that the NIR-to-MIR spectral indexes are ~-1.1, and the MIR spectral indexes are ~-0.3. Comparing the synthetic and observed values, we find that none of the models simultaneously match the measured NIR-to-MIR and 7.8-9.8 μm slopes. However, we note that measuring α MIR(7.8-9.8 μm) on the starburst-subtracted Spitzer/IRS spectrum gives values of the slopes (~-2) that are similar to the synthetic values obtained from the models.
Related projects
Nuclear Activity in Galaxies: a 3D Perspective from the Nucleus to the Outskirts
This project consists of two main research lines. First, the study of quasar-driven outflows in luminous and nearby obscured active galactic nuclei (AGN) and the impact that they have on their massive host galaxies (AGN feedback). To do so, we have obtained Gran Telescopio CANARIAS (GTC) infrared and optical observations with the instruments
Cristina
Ramos Almeida