HST counterparts to wandering IMBHs

Ana Luisa González Morán, Jorge Sánchez Almeida, Joao Calhau, Casiana Muñoz-Tuñón, José Miguel Rodríguez-Espinosa


Motivated by the detection of faint double-peak H$\alpha$ emission in the halo of low redshift galaxies which best scenario corresponds to accretion disks around intermediate-mass Black Holes (IMBHs). This work is focused on looking for HST counterparts. We follow two methodologies, first, we cross-match the positions of the IMBHs candidates with The Hubble Legacy Field GOODS-S Photometric Catalog (HST Catalog) within a radius of 0.5 arcseconds. And the second one, we examine the HST images directly. Among the 118 IMBHs candidates, we found 15 coincidences in the HST catalog and 35 in the images. We found that for 79\% of the counterparts, their SED are best fitted using a power-law model, supporting the scenario of having accretion disks around BH. The remaining 21% are best fitted using stellar population models obtaining ages younger than 500 Myr and stellar masses lower than 10$^8$ M$_{\odot}$.