High-spectral-resolution Observations of the [S II] Emission-line Doublet in the Filamentary Nebula Surrounding NGC 1275

Abstract

We analyze new high-spectral resolution SITELLE observations (R = $\lambda /\Delta \lambda$ = 7000) of the filamentary nebula surrounding NGC 1275, central galaxy of the Perseus cluster. We present here analysis of the \sii$\lambda 6716$ and \sii$\lambda 6731$ emission line doublet, using its ratio to determine the electron density of the optically emitting filaments. We compare these measurements with electron densities derived from deep Chandra X-ray observations of the intra-cluster medium (ICM) to determine if any correlations in density can be found. We report the detection of a clear dichotomy between the outer filaments, displaying on average lower \sii\text{ }emission line ratio of $\sim 1.1$ and the inner filaments displaying higher ratios of $\sim 1.3$. These results indicate that most of the gaseous filaments lie close to the low-density threshold for the density measurement of $\sim 10^2{\text{ cm}}^{-3}$. Using radial profiles, we find that the inner filaments have a roughly constant density, whereas the ICM density decreases with radius. In the outer filaments, we observe hints of local connections between the densities of the ICM and optical filaments, but no clear correlation seems to be observed overall. We also combined these density measurements with cold molecular CO gas observations to derive a relationship between temperature, density and pressure for the multiphase environment surrounding NGC 1275. Finally, we investigated potential models to explain the observed density measurements and explored similar studies of filamentary nebula around other central galaxies of cool-core galaxy clusters.

arXiv comment22 pages, 7 figures, published in ApJ

References in corpus (57)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• A very deep Chandra observation of the Perseus cluster: shocks, ripples and conduction
• Chandra imaging of the complex X-ray core of the Perseus cluster
• What is a Cool-Core Cluster? A Detailed Analysis of the Cores of the X-ray Flux-Limited HIFLUGCS Cluster Sample
• Chaotic cold accretion onto black holes
• The ROSAT Brightest Cluster Sample (BCS): -- III. Optical spectra of the central cluster galaxies
• XMM-Newton observations of the Perseus Cluster I: The temperature and surface brightness structure
• Turbulent Heating in Galaxy Clusters Brightest in X-rays
• On the prevalence of radio-loud AGN in brightest cluster galaxies: implications for AGN heating of cooling flows
• The Dark Matter Distribution in the Central Regions of Galaxy Clusters
• The Dark Matter Distribution in the Central Regions of Galaxy Clusters: Implications for CDM
• On the Nature of the NGC 1275 System
• The relationship between the optical Halpha filaments and the X-ray emission in the core of the Perseus cluster
• On the Origin of the Extended Halpha Filaments in Cooling Flow Clusters
• Radio Bubbles in Clusters
• Magnetic support of the optical emission line filaments in NGC 1275
• A Mechanism for Stimulating AGN Feedback by Lifting Gas in Massive Galaxies
• Mapping small-scale temperature and abundance structures in the core of the Perseus cluster
• Atmospheric gas dynamics in the Perseus cluster observed with Hitomi
• A wide Chandra view of the core of the Perseus cluster
• A Very Deep Chandra Observation of the Galaxy Group NGC 5813: AGN Shocks, Feedback, and Outburst History
• Cooling Time, Freefall Time, and Precipitation in the Cores of ACCEPT Galaxy Clusters
• The energy source of the filaments around the giant galaxy NGC1275
• On the origin and excitation of the extended nebula surrounding NGC 1275
• A very extended molecular web around NGC 1275
• Upgrading electron temperature and electron density diagnostic diagrams of forbidden line emission
• Optical Emission Line Nebulae in Galaxy Cluster Cores 1: The Morphological, Kinematic and Spectral Properties of the Sample
• Optical Spectroscopy of Halpha Filaments in Cool Core Clusters: Kinematics, Reddening, and Sources of Ionization
• Conduction and the Star-Formation Threshold in Brightest Cluster Galaxies
• Galaxy cluster mass profiles
• Optical IFU Observations of the Brightest Cluster Galaxy NGC 4696: The Case for a Minor Merger and Shock-excited Filaments
• SITELLE: An Imaging Fourier Transform Spectrometer for the Canada-France-Hawaii Telescope
• The nature of filamentary cold gas in the core of the Virgo Cluster
• A Reexamination of Electron Density Diagnostics for Ionized Gaseous Nebulae
• The ALMA Discovery of the Rotating Disk and Fast Outflow of Cold Molecular Gas in NGC 1275
• Chandra measurements of non-thermal-like X-ray emission from massive, merging, radio-halo clusters
• The Weak Shock in the Core of the Perseus Cluster
• Revealing the velocity structure of the filamentary nebula in NGC 1275 in its entirety
• HST imaging of the dusty filaments and nucleus swirl in NGC4696 at the centre of the Centaurus Cluster
• Hidden Cooling Flows in Clusters of Galaxies
• Molecular Gas in the Perseus Cooling Flow Galaxy, NGC 1275
• Emission-Line Properties of the Optical Filaments of NGC 1275
• The Complicated Evolution of the ACIS Contamination Layer over the Mission Life of the Chandra X-ray Observatory
• Radio jet-ISM interaction and positive radio-mechanical feedback in Abell 1795
• Machine Learning Approach to Integral Field Unit Spectroscopy Observations: I. HII Region Kinematics
• H$\alpha$-X-ray Surface Brightness Correlation for Filaments in Cooling Flow Clusters
• The VLT-MUSE and ALMA view of the MACS 1931.8-2635 brightest cluster galaxy
• High-Spectral Resolution Observations of the Optical Filamentary Nebula in NGC 1275
• A Machine Learning Approach to Integral Field Unit Spectroscopy Observations: II. HII Region LineRatios
• Inquiring into the nature of the Abell 2667 Brightest Cluster Galaxy: physical properties from MUSE
• Discovery of inverse-Compton X-ray emission and estimate of the volume-averaged magnetic field in a galaxy group
• A Novel Machine Learning Approach to Disentangle Multi-Temperature Regions in Galaxy Clusters
• The Intra-Cluster Medium