Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-10-28T19:27:42.247Z Has data issue: false hasContentIssue false

Updated Calculations of the Spectral-Line Radiation Force & Mass-Loss Rates for AGN Outflows

Published online by Cambridge University Press:  28 October 2024

Aylecia S. Lattimer*
Affiliation:
Department of Astrophysical & Planetary Sciences, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309, USA
Steven Cranmer*
Affiliation:
Department of Astrophysical & Planetary Sciences, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309, USA
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Photon-driven flows have been studied for almost a century, and a quantitative description of the radiative forces on atoms and ions is important for understanding a wide variety of systems, including active galactic nuclei (AGN). The colloquially-termed “radiation pressure” of line-driven winds plays an important role in driving outflows in these environments. Quantifying the associated forces is crucial to understanding how these flows enable interactive mechanisms within these environments, such as AGN feedback. Here we provide new calculations of the dimensionless line strength parameter due to radiation driving. For representative AGN, we calculate the photoionization balance at each step along the line of sight (LOS) to the proposed wind-launching region above the accretion disk. We then use a recently compiled database of approximately 5.6 million spectral lines to compute the strength of the line-driving force on the gas and the mass-loss rates resulting from these outflows. We also introduce a “shielding factor’’ that increases the magnitude of the accretion disk column density prior to the launch radius. This shielding factor simulates a proposed inner “failed wind” region that is thought to shield the outflowing gas from becoming over-ionized by the central source. We also revisit and formalize the role of the commonly-used ionization parameter in setting the properties of the accelerating gas.

Type
Contributed Paper
Creative Commons
Creative Common License - CCCreative Common License - BY
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.
Copyright
© The Author(s), 2024. Published by Cambridge University Press on behalf of International Astronomical Union

References

Castor, J. I. 1974, MNRAS, 169, 279.CrossRefGoogle Scholar
Castor, J. I., Abbott, D. C., & Klein, R. I. 1975, ApJ, 195, 157.CrossRefGoogle Scholar
Cavaliere, A., Lapi, A., & Menci, N. 2002, ApJ (Letters), 581, L1.Google Scholar
Cunto, W. & Mendoza, C. 1992, Rev. Mexicana AyA, 23, 107 Google Scholar
Cunto, W., Mendoza, C., Ochsenbein, F., et al. 1993, A&A, 275, L5 Google Scholar
Del Zanna, G., Dere, K. P., Young, P. R., et al. 2021, ApJ, 909, 38.CrossRefGoogle Scholar
Dere, K. P., Landi, E., Mason, H. E., et al. 1997, A&AS, 125, 149.Google Scholar
Fabian, A. C. 2012, ARAA, 50, 455.CrossRefGoogle Scholar
Giustini, M. & Proga, D. 2019, A&A, 630, A94.Google Scholar
Harrison, C. M., Costa, T., Tadhunter, C. N., et al. 2018, Nature Astronomy, 2, 198.CrossRefGoogle Scholar
Higginbottom, N., Proga, D., Knigge, C., et al. 2014, ApJ, 789, 19.CrossRefGoogle Scholar
Hillier, D. J. 1990, A&A, 231, 116 Google Scholar
Hillier, D. J. & Miller, D. L. 1998, ApJ, 496, 407. doi: 10.1086/305350 CrossRefGoogle Scholar
Hillier, D. J. & Lanz, T. 2001, Spectroscopic Challenges of Photoionized Plasmas, 247, 343Google Scholar
Hopkins, P. F., Torrey, P., Faucher-Giguère, C.-A., et al. 2016, MNRAS, 458, 816.CrossRefGoogle Scholar
King, A. & Pounds, K. 2015, ARAA, 53, 115.CrossRefGoogle Scholar
Kramida, A., Yu., Ralchenko, Reader, J., & NIST ASD Team. 2018, NIST Atomic Spectra Database (ver. 5.6.1) [Online]. Available: https://physics.nist.gov/asd Google Scholar
Lattimer, A. S. & Cranmer, S. R. 2021, ApJ, 910, 48.CrossRefGoogle Scholar
Magorrian, J., Tremaine, S., Richstone, D., et al. 1998, AJ, 115, 2285.CrossRefGoogle Scholar
Mendoza, C., Bautista, M. A., Deprince, J., et al. 2021, Atoms, 9, 12.CrossRefGoogle Scholar
Murray, N., Chiang, J., Grossman, S. A., et al. 1995, ApJ, 451, 498.CrossRefGoogle Scholar
Nomura, M., Ohsuga, K., Takahashi, H. R., et al. 2016, PASJ, 68, 16.CrossRefGoogle Scholar
Ostriker, J. P., Choi, E., Ciotti, L., et al. 2010, ApJ, 722, 642.CrossRefGoogle Scholar
Proga, D., Stone, J. M., & Kallman, T. R. 2000, ApJ, 543, 686.CrossRefGoogle Scholar
Proga, D. 2007, ASP-CS, The Central Engine of Active Galactic Nuclei, 373, 267.Google Scholar
Proga, D. & Kallman, T. R. 2004, ApJ, 616, 688.CrossRefGoogle Scholar
Rees, M. J., Netzer, H., & Ferland, G. J. 1989, ApJ, 347, 640.CrossRefGoogle Scholar
Risaliti, G. & Elvis, M. 2010, A&A, 516, A89.Google Scholar
Silk, J. & Rees, M. J. 1998, A&A, 331, L1.Google Scholar
Zhu, Y., Bu, D.-F., Yang, X.-H., et al. 2022, MNRAS, 513, 1141.CrossRefGoogle Scholar