The Optical Polarization and Warm Absorber in IRAS [FORMULA][F]17020+4544[/F][/FORMULA]
| Autor: | Dirk Grupe, Karen M. Leighly, Derek Wills, Beverley J. Wills, Laura E. Kay |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Physics
010308 nuclear & particles physics Continuum (design consultancy) Balmer series Astronomy and Astrophysics Optical polarization Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Polarization (waves) 01 natural sciences Galaxy symbols.namesake Space and Planetary Science 0103 physical sciences symbols Astrophysics::Solar and Stellar Astrophysics Emission spectrum 10. No inequality Absorption (electromagnetic radiation) 010303 astronomy & astrophysics Astrophysics::Galaxy Astrophysics Line (formation) |
| Zdroj: | The Astrophysical Journal. 489:L137-L140 |
| ISSN: | 0004-637X |
| DOI: | 10.1086/316793 |
| Popis: | We report the detection of ionized absorption in the ASCA spectrum of the narrow-line Seyfert 1 galaxy IRAS 17020+4544. Subsequent optical spectropolarimetry revealed high polarization increasing from 3% in the red to 5% in the blue, indicating electron or dust scattering as a likely origin. The broad emission line H$\alpha$ is somewhat less polarized than the continuum, supporting a location of the polarizing material within the AGN. The Balmer line decrement and reddened optical spectrum support the presence of a dusty warm absorber in this object. We compared the broad band optical polarization and ionized X-ray absorption of a collection of Seyfert 1 and 1.5 galaxies, excluding classes of objects that are likely to have significant neutral X-ray absorption. Warm absorber objects are generally more likely to have high optical polarization than objects with no detected ionized absorption. This result lends additional support to the idea that the warm absorber is associated with dust and implies either that dust transmission is responsible for at least part of the polarization or that the polarization is revealed because of the dimming of the optical spectrum. Spectropolarimetry of Seyfert 1s generally locates the scattering material inside the narrow-line region and often close to or within the broad line region, consistent with estimates of the location of the dusty warm absorber. |
| Databáze: | OpenAIRE |
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