Difficulties in Mid-Infrared selection of AGN in dwarf galaxies

Abstract

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.

7 pages, 7 figures, 1 table, accepted for publication on MNRAS

References in corpus (9)

• Observational evidence for intermediate-mass black holes
• Black Holes on FIRE: Stellar Feedback Limits Early Feeding of Galactic Nuclei
• Photometric Redshift with Bayesian Priors on Physical Properties of Galaxies
• X-ray constraints on the local supermassive black hole occupation fraction
• Mid-Infrared Colors of Dwarf Galaxies: Young Starbursts Mimicking Active Galactic Nuclei
• Relative Role of Stars and Quasars in Cosmic Reionization
• Radio jets from AGN in dwarf galaxies in the COSMOS survey: mechanical feedback out to redshift $\sim$3.4
• Observational Signatures of High-Redshift Quasars and Local Relics of Black Hole Seeds
• How AGN and SNe feedback affect mass transport and black hole growth in high redshift galaxies

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• Population statistics of intermediate mass black holes in dwarf galaxies using the NewHorizon simulation
• A Low Incidence of Mid-Infrared Variability in Dwarf Galaxies
• Identification and Characterization of a Large Sample of Distant Active Dwarf Galaxies in XMM-SERVS
• Ejection of supermassive black holes and implications for merger rates in fuzzy dark matter haloes
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• Variation of optical and infrared properties of galaxies with their surface brightness
• Mid-infrared Variability-based AGN Selection using the Multi-epoch Photometric Data from WISE
• Morphological Feature Distances Among the Spectral Types of SDSS Galaxies
• The black hole population in low-mass galaxies in large-scale cosmological simulations