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Title: Enhanced Polarized Emission from the One-parsec-scale Hotspot of 3C 84 as a Result of the Interaction with the Clumpy Ambient Medium

Abstract

We present Very Long Baseline Array polarimetric observations of the innermost jet of 3C 84 (NGC 1275) at 43 GHz. A significant polarized emission is detected at the hotspot of the innermost restarted jet, which is located 1 pc south from the radio core. While the previous report presented a hotspot at the southern end of the western limb, the hotspot location has been moved to the southern end of the eastern limb. Faraday rotation is detected within an entire bandwidth of the 43 GHz band. The measured rotation measure (RM) is at most (6.3 ± 1.9) × 10{sup 5} rad m{sup −2} and might be slightly time variable on the timescale of a month by a factor of a few. Our measured RM and the RM previously reported by the CARMA and SMA observations cannot be consistently explained by the spherical accretion flow with a power-law profile. We propose that a clumpy/inhomogeneous ambient medium is responsible for the observed RM. Using an equipartition magnetic field, we derive the electron density of 2 × 10{sup 4} cm{sup −3}. Such an electron density is consistent with the cloud of the narrow line emission region around the central engine. We also discussmore » the magnetic field configuration from the black hole scale to the parsec scale and the origin of low polarization.« less

Authors:
;  [1];  [2]; ;  [3]; ;  [4]
  1. National Astronomical Observatory of Japan, Osawa 2-21-1, Mitaka, Tokyo 181-8588 (Japan)
  2. Theoretical Astrophysics, Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)
  3. The Academia Sinica Institute of Astronomy and Astrophysics, AS/NTU. No.1, Section 4, Roosevelt Road, Taipei 10617, Taiwan, R.O.C. (China)
  4. Instituto di Radioastronomia, Via P. Gobetti, 101, I-40129 Bologna (Italy)
Publication Date:
OSTI Identifier:
22679711
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 849; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; CLOUDS; ELECTRON DENSITY; ELECTRONS; EMISSION; FARADAY EFFECT; GALAXIES; GHZ RANGE; INTERACTIONS; LIMBS; MAGNETIC FIELD CONFIGURATIONS; MAGNETIC FIELDS; POLARIZATION; ROTATION; SPHERICAL CONFIGURATION

Citation Formats

Nagai, H., Kino, M., Fujita, Y., Nakamura, M., Asada, K., Orienti, M., and Giovannini, G., E-mail: hiroshi.nagai@nao.ac.jp. Enhanced Polarized Emission from the One-parsec-scale Hotspot of 3C 84 as a Result of the Interaction with the Clumpy Ambient Medium. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA8E43.
Nagai, H., Kino, M., Fujita, Y., Nakamura, M., Asada, K., Orienti, M., & Giovannini, G., E-mail: hiroshi.nagai@nao.ac.jp. Enhanced Polarized Emission from the One-parsec-scale Hotspot of 3C 84 as a Result of the Interaction with the Clumpy Ambient Medium. United States. doi:10.3847/1538-4357/AA8E43.
Nagai, H., Kino, M., Fujita, Y., Nakamura, M., Asada, K., Orienti, M., and Giovannini, G., E-mail: hiroshi.nagai@nao.ac.jp. Wed . "Enhanced Polarized Emission from the One-parsec-scale Hotspot of 3C 84 as a Result of the Interaction with the Clumpy Ambient Medium". United States. doi:10.3847/1538-4357/AA8E43.
@article{osti_22679711,
title = {Enhanced Polarized Emission from the One-parsec-scale Hotspot of 3C 84 as a Result of the Interaction with the Clumpy Ambient Medium},
author = {Nagai, H. and Kino, M. and Fujita, Y. and Nakamura, M. and Asada, K. and Orienti, M. and Giovannini, G., E-mail: hiroshi.nagai@nao.ac.jp},
abstractNote = {We present Very Long Baseline Array polarimetric observations of the innermost jet of 3C 84 (NGC 1275) at 43 GHz. A significant polarized emission is detected at the hotspot of the innermost restarted jet, which is located 1 pc south from the radio core. While the previous report presented a hotspot at the southern end of the western limb, the hotspot location has been moved to the southern end of the eastern limb. Faraday rotation is detected within an entire bandwidth of the 43 GHz band. The measured rotation measure (RM) is at most (6.3 ± 1.9) × 10{sup 5} rad m{sup −2} and might be slightly time variable on the timescale of a month by a factor of a few. Our measured RM and the RM previously reported by the CARMA and SMA observations cannot be consistently explained by the spherical accretion flow with a power-law profile. We propose that a clumpy/inhomogeneous ambient medium is responsible for the observed RM. Using an equipartition magnetic field, we derive the electron density of 2 × 10{sup 4} cm{sup −3}. Such an electron density is consistent with the cloud of the narrow line emission region around the central engine. We also discuss the magnetic field configuration from the black hole scale to the parsec scale and the origin of low polarization.},
doi = {10.3847/1538-4357/AA8E43},
journal = {Astrophysical Journal},
number = 1,
volume = 849,
place = {United States},
year = {Wed Nov 01 00:00:00 EDT 2017},
month = {Wed Nov 01 00:00:00 EDT 2017}
}