AGN STORM 2 : VIII. Investigating the narrow absorption lines in Mrk 817 using HST-COS observations
We observed the Seyfert 1 galaxy Mrk 817 during an intensive multiwavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in the Hubble Space Telescope/ Cosmic Origins Spectrograph spectra, both during the campaign and in other epochs...
| Authors: | , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2024 |
| Country: | Brasil |
| Institution: | Universidade Federal do Rio Grande do Sul (UFRGS) |
| Repository: | Repositório Institucional da UFRGS |
| Language: | English |
| OAI Identifier: | oai:www.lume.ufrgs.br:10183/281563 |
| Online Access: | http://hdl.handle.net/10183/281563 |
| Access Level: | Open access |
| Keyword: | Galáxias ativas Nucleo galatico Galaxias seyfert Active galaxies Active galactic nuclei Seyfert galaxies |
| Summary: | We observed the Seyfert 1 galaxy Mrk 817 during an intensive multiwavelength reverberation mapping campaign for 16 months. Here, we examine the behavior of narrow UV absorption lines seen in the Hubble Space Telescope/ Cosmic Origins Spectrograph spectra, both during the campaign and in other epochs extending over 14 yr. We conclude that, while the narrow absorption outflow system (at −3750 km s−1 with FWHM = 177 km s−1 ) responds to the variations of the UV continuum as modified by the X-ray obscurer, its total column density (log NH = 19.5 - + 0.13 0.61 cm−2 ) did not change across all epochs. The adjusted ionization parameter (scaled with respect to the variations in the hydrogen-ionizing continuum flux) is log UH = −1.0 - + 0.3 0.1. The outflow is located at a distance smaller than 38 pc from the central source, which implies a hydrogen density of nH > 3000 cm−3 . The absorption outflow system only covers the continuum emission source and not the broad emission line region, which suggests that its transverse size is small (< 1016 cm), with potential cloud geometries ranging from spherical to elongated along the line of sight. |
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