ALMA allows us to study these regions buried within thick gas layers since mm-wave emission is almost unaffected by dust up to column densities up to Also, ALMA allows us to resolve each nucleus, thanks to its unprecedented resolution of 0.03 arcsec. MRK463 NGC6240 ARP220 LEDA17883 ESO509 ESO253 RESULTS SUPERMASSIVE BLACK HOLE PAIRS AT SEPARATIONS <1 KPC AND THEIR ROLE IN BLACK HOLE GROWTH Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile Centro de Astrofísica y Tecnologías Afines National RadioAstronomy Observatory This investigation aims to study the growth in black holes undergoing a merging process, specifically those at separations below 1 Kpc. This is not a straightforward task since it has been found that merging-triggered AGNs are likely to become heavily obscured by gas and dust (Ricci et al., 2017, 2021) Objective Method Millimetric and X-ray emission relation It has been studied that X-rays are a good tracer for black hole growth. A relation between x-rays and mm-emission has recently been found for isolated AGNs (Kawamuro et al. 2022). If this relation holds for dual AGNs it could be used to trace the black hole growth at these separations. Macarena Droguett Callejas , Ezequiel Treister , Loreto Barcos-Muñoz CONCLUSIONS MJDROGUETT@UC.CL SAMPLE AND OBSERVATIONS INTRODUCTION 3 The sample of this study can be divided into two groups. The first one is a selection of known dual AGNs and dual nuclei (Mrk463, NGC6240, ARP220 and UGC4211); this is ALMA archival data with observations from the main array. The second group is a selection from the GOALS survey. This is a survey of the most luminous infrared galaxies in the local universe, which is a great place to look for dual AGNs. The observations of this group correspond to ALMA archival from the ACA configuration. 1,2 1,2 Figure 1: ALMA continuum images of two dual AGN candidates and one dual nuclei. The Magenta line depicts 0.1 arcsec. Each nucleus of confirmed dual AGNs follows the studied relation. Isolated AGNs in the GOALS sample also follow the relation. In-band spectral indexes were computed, indicating emission coming from dust from the sources distant from the relation. This value indicates that if an AGN was present, it would not be dominant. The correlation between mm and X-ray emission established for isolated AGN also holds for dual systems. The relation between mm and x-ray emission can be used to identify heavily obscured AGN in previously unidentified systems. A better understanding of the black hole merging process will be key in predicting the number of gravitational wave events. Ricci, C. et al. MNRAS 468(2):1273–1299, June 2017. doi:10.1093/mnras/stx173 Ricci, C. et al, MNRAS. 506(4):5935–5950, October 2021. doi:10.1093/mnras/stab2052 Kawamuro, T. et al., The Astrophysical Journal, 938(1):87, October 2022. doi: 10.3847/1538-4357/ac8794 Koss, M. et al., The Astrophysical Journal, 942(1):L24, January 2023. doi: 10.3847/2041-8213/aca8f0. 1 2 3 Figure 2: The blue-filled circles are the data that Kawamuro et al. (2023) used to compute the relation (red line) between mm-emission and x-ray emission for isolated AGNs. Black dots are our selection from GOALS. Confirmed dual AGNs and other sources of interest are appropriately labelled. For sources without an exact value of column density, repeated labels filled with colours indicate the change in the position of the source when corrected by column densities of 10 (light purple) or 10 (dark purple). The black arrow indicates a lower limit. 24 REFERENCES FUTURE WORK Perform the same analysis for dual AGN candidates observed with ALMA’s cycle 9. This program aims to determine the incidence of dual AGN in late state-merger systems by observing 12 sources. Project Code: 2022.1.01348.S Using the prescription of Murphy et al. (2012) and IR luminosities reported by Sanders et al. (2003), we estimated that the contribution of star formation to the mm and x-ray emission could account