A Sample of Active Galactic Nuclei with Intermediate-mass Black Holes Extended to $z \approx$ 0.6
Fuente:
arXiv
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866909031906410496 |
|---|---|
| author | Liu, Wen-Juan Ho, Luis C. Dong, Xiao-Bo Yao, Su Lira, Paulina Guo, Yicheng |
| author_facet | Liu, Wen-Juan Ho, Luis C. Dong, Xiao-Bo Yao, Su Lira, Paulina Guo, Yicheng |
| contents | We present a sample of 930 intermediate-mass black hole (IMBH) active galactic nuclei (AGNs) with black hole masses of $M_\mathrm{BH} \leqslant 2 \times 10^{6}$ M$_{\odot}$, uniformly selected from the Seventeenth Data Release of the Sloan Digital Sky Survey, based on the detection of broad H$α$ or H$β$ emission lines. Taking advantage of the wide wavelength coverage of BOSS/eBOSS spectroscopy, our sample extends the redshift coverage of low-$z$ IMBH AGNs to $z\leqslant0.57$, significantly improving upon previous studies that where generally limited to $z\leqslant0.35$. This sample encompasses black hole masses from $10^{4.0}$ to $10^{6.3}$ M$_{\odot}$, with Eddington ratios ranging from 0.01 to 1.9. Among the $z>0.3$ subset, 24 sources exhibit detectable broad Mg II $λ\lambda2796,2803$ emission lines, including eight confirmed by independent DESI spectra. A preliminary analysis reveals a marked decline in both the maximum accretion rate ($L/L_\mathrm{Edd}$) and broad H$α$ luminosity with decreasing redshift, possibly reflecting a cosmic evolution of accretion activity at the low-mass end, akin to the ``downsizing'' evolutionary trend seen in high-mass AGNs. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2503_12898 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | A Sample of Active Galactic Nuclei with Intermediate-mass Black Holes Extended to $z \approx$ 0.6 Liu, Wen-Juan Ho, Luis C. Dong, Xiao-Bo Yao, Su Lira, Paulina Guo, Yicheng Astrophysics of Galaxies We present a sample of 930 intermediate-mass black hole (IMBH) active galactic nuclei (AGNs) with black hole masses of $M_\mathrm{BH} \leqslant 2 \times 10^{6}$ M$_{\odot}$, uniformly selected from the Seventeenth Data Release of the Sloan Digital Sky Survey, based on the detection of broad H$α$ or H$β$ emission lines. Taking advantage of the wide wavelength coverage of BOSS/eBOSS spectroscopy, our sample extends the redshift coverage of low-$z$ IMBH AGNs to $z\leqslant0.57$, significantly improving upon previous studies that where generally limited to $z\leqslant0.35$. This sample encompasses black hole masses from $10^{4.0}$ to $10^{6.3}$ M$_{\odot}$, with Eddington ratios ranging from 0.01 to 1.9. Among the $z>0.3$ subset, 24 sources exhibit detectable broad Mg II $λ\lambda2796,2803$ emission lines, including eight confirmed by independent DESI spectra. A preliminary analysis reveals a marked decline in both the maximum accretion rate ($L/L_\mathrm{Edd}$) and broad H$α$ luminosity with decreasing redshift, possibly reflecting a cosmic evolution of accretion activity at the low-mass end, akin to the ``downsizing'' evolutionary trend seen in high-mass AGNs. |
| title | A Sample of Active Galactic Nuclei with Intermediate-mass Black Holes Extended to $z \approx$ 0.6 |
| topic | Astrophysics of Galaxies |
| url | https://arxiv.org/abs/2503.12898 |