Broad Band Photometric Reverberation Mapping of NGC 4395
| Autor: | Stephen E. Rafter, Ehud Behar, Haim Edri, Shai Kaspi, Doron Chelouche |
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| Rok vydání: | 2012 |
| Předmět: |
Physics
Active galactic nucleus Cosmology and Nongalactic Astrophysics (astro-ph.CO) Astrophysics::High Energy Astrophysical Phenomena Time lag Broad band FOS: Physical sciences Astronomy and Astrophysics Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Light curve law.invention Black hole Telescope Space and Planetary Science Observatory law Reverberation mapping Astrophysics::Galaxy Astrophysics Astrophysics - Cosmology and Nongalactic Astrophysics |
| DOI: | 10.48550/arxiv.1206.4486 |
| Popis: | We present results of broad band photometric reverberation mapping (RM) to measure the radius of the broad line region, and subsequently the black hole mass (M$_{\rm BH}$), in the nearby, low luminosity active galactic nuclei (AGN) NGC 4395. Using the Wise Observatory's 1m telescope equipped with the SDSS g$'$, r$'$ and i$'$ broad band filters, we monitored NGC 4395 for 9 consecutive nights and obtained 3 light curves each with over 250 data points. The g$'$ and r$'$ bands include time variable contributions from H$\beta$ and H$\alpha$ (respectively) plus continuum. The i$'$ band is free of broad lines and covers exclusively continuum. We show that by looking for a peak in the difference between the cross-correlation and the auto-correlation functions for all combinations of filters, we can get a reliable estimate of the time lag necessary to compute M$_{\rm BH}$. We measure the time lag for H$\alpha$ to be $3.6 \pm 0.8 $ hours, comparable to previous studies using the line resolved spectroscopic RM method. We argue that this lag implies a black hole mass of M$_{\rm BH} = (4.9 \pm 2.6) \times 10^{4}$ \Msun . |
| Databáze: | OpenAIRE |
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