High Resolution Spectro-Polarimetric Observations of the Optical Filaments surrounding NGC 1275 with ESPaDOnS

@misc{vigneron2026high,
  title = {{High Resolution Spectro-Polarimetric Observations of the Optical Filaments surrounding NGC 1275 with ESPaDOnS}},
  author = {Benjamin Vigneron and Julie Hlavacek-Larrondo and Luca Fabiani and Lison Malo and Carter Lee Rhea and Megan Donahue and Jorge Karolt Barrera Ballesteros and Hyunseop Choi and Nadine Manset},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.13719},
  eprint = {2610.13719},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.13719},
}

TY  - UNPB
TI  - High Resolution Spectro-Polarimetric Observations of the Optical Filaments surrounding NGC 1275 with ESPaDOnS
AU  - Benjamin Vigneron
AU  - Julie Hlavacek-Larrondo
AU  - Luca Fabiani
AU  - Lison Malo
AU  - Carter Lee Rhea
AU  - Megan Donahue
AU  - Jorge Karolt Barrera Ballesteros
AU  - Hyunseop Choi
AU  - Nadine Manset
PY  - 2026
DA  - 2026/10/09
PB  - arXiv
DO  - 10.48550/arxiv.2610.13719
UR  - https://arxiv.org/abs/2610.13719
AB  - We analyze archival high spectral resolution ESPaDOnS spectropolarimetric observations (R = λ/Δλ = 68000) of three targeted locations within the filamentary nebula surrounding NGC 1275. We present here the analysis of the main filaments emission lines, namely: [NII]λ6584, Hα, and [NII]λ6548, across our three pointings displaying clear detectable emission, with one also showing additional [SII]λ6716 and [SII]λ6731 emission line doublet. Using a Markov Chain Monte-Carlo (MCMC) algorithm and thanks to the exceptionally high spectral resolution of the observations, we resolve for the first time each of the emission lines within one of the pointings into a set of three emission components with a remarkable velocity dispersion contrast (σ_1 ∼ 25 km/s, σ_2 ∼ 90 km/s and σ_3 ∼ 208 km/s). We also perform flux ratios of the three detected emission components, which reveal differences in electron density and ionization sources. Consequently, the ESPaDOnS observations appear to reveal for the first time the overlap of an outer quiescent filament and a central turbulent filament likely affected by the AGN activity at a distance of ∼ 6.8'' (∼ 2.5 kpc) from the central BCG. Finally, ESPaDOnS polarimetric data of one of the pointing allows us to confirm an average linear polarization degree of ∼ 0.15−0.14% and an angle of polarization of 5.3±25.7^∘ for the optical emission of the filaments, as well as polarization dips associated with the Hα emission line and its multiple emission components. We interpret these features and measurements as tentative polarization due to dust scattering.
ER  -