Chandra detects low-luminosity AGN with $M_\mathrm{BH}=10^{4}-10^{6}~M_\mathrm{\odot}$ in nearby ($z<0.5$), dwarf and star-forming galaxies

• DOI: 10.48550/arxiv.2406.18730
• Publication Date: 2024-06-26
• Authors: M. Singha; J. A. Sarmiento; Sangeeta Malhotra; James E. Rhoads; L. Y. Aaron Yung; Junxian Wang; Zhen-Ya Zheng; Ruqiu Lin; Keunho Kim; Jia-Lai Kang; Santosh Harish
• Keywords: Star (game theory)

We searched the Chandra and XMM archives for observations of 900 green pea galaxies to find AGN signatures. Green peas are low-mass with prominent emission lines, similar in size star formation rate high-redshift dwarf galaxies. Of 29 found, 9 show X-ray detections $S/N>3$. The 2-10 keV luminosity these sources exceeds $10^{40}~\mathrm{erg~s}^{-1}$, 2 exceeding $10^{41}~\mathrm{erg~s}^{-1}$, suggesting presence intermediate-mass black holes (IMBH) or low-luminosity (LLAGN) BH masses between $100-10^6M_\mathrm{\odot}$. All detected (plus 6 additional sources) He~II$\lambda4686$ a broad component H$\alpha$ line, indicating winds. line widths He II$\lambda4686$ emitting gas clouds weakly correlated ($R^{2}=0.15$), is inconsistent winds from super-Eddington accretors. However, ratio shows an anti-correlation metallicity 5 out sources, implying ultraluminous key contributors observed luminosity. This could be due accretors IMBH. much higher than that produced by Wolf-Rayet stars supernovae-driven Thus, can only explained over $100~M_\mathrm{\odot}$. Our findings suggest LLAGN galaxies, $10^4-10^6M_\mathrm{\odot}$. Given Peas' role as significant Lyman Continuum leakers, have contributed significantly cosmic reionization.