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While massive black holes (MBHs) are known to inhabit all massive galaxies, their ubiquitous presence in dwarf galaxies has not been confirmed yet, with only a limited number of sources detected so far. Recently, some studies proposed infrared emission as an alternative way to identify MBHs in dwarfs, based on a similar approach usually applied to quasars. In this study, by accurately combining optical and infrared data taking into account resolution effects and source overlapping, we investigate in detail the possible limitations of this approach with current ground-based facilities, finding a quite low ($sim$0.4 per cent) fraction of active MBH in dwarfs that are luminous in mid-infrared, consistent with several previous results. Our results suggest that the infrared selection is strongly affected by several limitations that make the identification of MBHs in dwarf galaxies currently prohibitive, especially because of the very poor resolution compared to optical surveys, and the likely contamination by nearby sources, although we find a few good candidates worth further follow-ups. Optical, X-ray and radio observations, therefore, still represent the most secure way to search for MBH in dwarfs.
In this research, we provide a new, efficient method to select infrared (IR) active galatic nucleus (AGN). In the past, AGN selection in IR had been established by many studies using color-color diagrams. However, those methods have a problem in comm
The optical time-domain astronomy has grown rapidly in the past decade but the dynamic infrared sky is rarely explored. Aiming to construct a sample of mid-infrared outburst in nearby galaxies (MIRONG), we have conducted a systematical search of low-
Mid-infrared photometry provides a robust technique for identifying active galaxies. While the ultraviolet to mid-infrared continuum of normal galaxies is dominated by the composite stellar black body curve and peaks at approximately 1.6 microns, the
We have developed an efficient Active Galactic Nucleus (AGN) selection method using 18-band Spectral Energy Distribution (SED) fitting in mid-infrared (mid-IR). AGNs are often obscured by gas and dust, and those obscured AGNs tend to be missed in opt
The estimate of the number and space density of obscured AGN over cosmic time still represents an open issue. While the obscured AGN population is a key ingredient of the X-ray background synthesis models and is needed to reproduce its shape, a compl