تقرير
Radio Scrutiny of the X-ray-Weak Tail of Low-Mass Active Galactic Nuclei: A Novel Signature of High-Eddington Accretion?
| العنوان: | Radio Scrutiny of the X-ray-Weak Tail of Low-Mass Active Galactic Nuclei: A Novel Signature of High-Eddington Accretion? |
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| المؤلفون: | Paul, Jeremiah D., Plotkin, Richard M., Brandt, W. N., Ellis, Christopher H., Gallo, Elena, Greene, Jenny E., Ho, Luis C., Kimball, Amy E., Haggard, Daryl |
| سنة النشر: | 2024 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena |
| الوصف: | The supermassive black holes ($M_{\rm BH} \sim 10^{6}$$-$$10^{10}~M_\odot$) that power luminous active galactic nuclei (AGNs), i.e., quasars, generally show a correlation between thermal disk emission in the ultraviolet (UV) and coronal emission in hard X-rays. In contrast, some "massive" black holes (mBHs; $M_{\rm BH} \sim 10^{5}$$-$$10^{6}~M_\odot$) in low-mass galaxies present curious X-ray properties with coronal radiative output up to 100$\times$ weaker than expected. To examine this issue, we present a pilot study incorporating Very Large Array radio observations of a sample of 18 high-accretion-rate (Eddington ratios $L_{\rm bol}/L_{\rm Edd} > 0.1$), mBH-powered AGNs ($M_{\rm BH} \sim 10^{6}~M_\odot$) with Chandra X-ray coverage. Empirical correlations previously revealed in samples of radio-quiet, high-Eddington AGNs indicate that the radio$-$X-ray luminosity ratio, $L_{\rm R}/L_{\rm X}$, is approximately constant. Through multiwavelength analysis, we instead find that the X-ray-weaker mBHs in our sample tend toward larger values of $L_{\rm R}/L_{\rm X}$ even though they remain radio-quiet per their optical$-$UV properties. This trend results in a tentative but highly intriguing correlation between $L_{\rm R}/L_{\rm X}$ and X-ray weakness, which we argue is consistent with a scenario in which X-rays may be preferentially obscured from our line of sight by a "slim" accretion disk. We compare this observation to weak emission-line quasars (AGNs with exceptionally weak broad-line emission and a significant X-ray-weak fraction) and conclude by suggesting that our results may offer a new observational signature for finding high-accretion-rate AGNs. Comment: Accepted for publication in ApJ. 26 pages, 8 figures, 6 tables |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2404.02423 |
| رقم الأكسشن: | edsarx.2404.02423 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |