A Detection of Sgr A* in the far infrared

Abstract

We report the first detection of the Galactic Centre massive black hole, Sgr~A*, in the far infrared. Our measurements were obtained with PACS on board the \emph{Herschel} satellite at $100\mu \mathrm{m}$ and $160\mu \mathrm{m}$. While the warm dust in the Galactic Centre is too bright to allow for a direct detection of Sgr~A*, we measure a significant and simultaneous variation of its flux of $\Delta F_{\nu \widehat{=}160\mu \mathrm{m}}=(0.27\pm 0.06)\mathrm{Jy}$ and $\Delta F_{\nu \widehat{=}100\mu \mathrm{m}}=(0.16\pm 0.10)\mathrm{Jy}$ during one observation. The significance level of the $160\mu \mathrm{m}$ band variability is $4.5\sigma$ and the corresponding $100\mu \mathrm{m}$ band variability is significant at $1.6\sigma$. We find no example of an equally significant false positive detection. Conservatively assuming a variability of $25\%$ in the FIR, we can provide upper limits to the flux. Comparing the latter with theoretical models we find that 1D RIAF models have difficulties explaining the observed faintness. However, the upper limits are consistent with modern ALMA and VLA observations. Our upper limits provide further evidence for a spectral peak at $\sim 10^{12}\mathrm{Hz}$ and constrain the number density of $\gamma \sim 100$ electrons in the accretion disk and or outflow.

arXiv commentaccepted for publication in APJ

References in corpus (49)

• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• Advection-Dominated Accretion: A Self-Similar Solution
• Hot Accretion Flows Around Black Holes
• The Galactic Center Massive Black Hole and Nuclear Star Cluster
• Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
• Drizzle: A Method for the Linear Reconstruction of Undersampled Images
• Chandra X-ray Spectroscopic Imaging of Sgr A* and the Central Parsec of the Galaxy
• Nonthermal Electrons in Radiatively Inefficient Accretion Flow Models of Sagittarius A*
• Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
• The Supermassive Black Hole at the Galactic Center
• An Update on Monitoring Stellar Orbits in the Galactic Center
• Chandra X-Ray Observatory (CXO):Overview
• Preparing Red-Green-Blue (RGB) Images from CCD Data
• Radiative Models of Sgr A* from GRMHD Simulations
• The Submillimeter Bump in Sgr A* from Relativistic MHD Simulations
• A public code for general relativistic, polarised radiative transfer around spinning black holes
• Evidence for X-ray synchrotron emission from simultaneous mid-IR to X-ray observations of a strong Sgr A* flare
• On The Nature of the Variable Infrared Emission from Sgr A*
• Sagittarius A* Accretion Flow and Black Hole Parameters from General Relativistic Dynamical and Polarized Radiative Modeling
• Hybrid Thermal-Nonthermal Synchrotron Emission from Hot Accretion Flows
• A prescription for the turbulent heating of astrophysical plasmas
• A near-IR variability study of the Galactic black hole: a red noise source with no detected periodicity
• The Disc-Jet Symbiosis Emerges: Modeling the Emission of Sagittarius A* with Electron Thermodynamics
• Variability of Sagittarius A* - Flares at 1 Millimeter
• Radio and Millimeter Monitoring of Sgr A*: Spectrum, Variability, and Constraints on the G2 Encounter
• Coupled jet-disk model for Sgr A*: explaining the flat-spectrum radio core with GRMHD simulations of jets
• Millimeter Flares and VLBI Visibilities from Relativistic Simulations of Magnetized Accretion onto the Galactic Center Black Hole
• On The Nature of the Compact Dark Mass at the Galactic Center
• StarFinder: an IDL GUI based code to analyze crowded fields with isoplanatic correcting PSF fitting
• Simultaneous Multi-Wavelength Observations of Sgr A* during 2007 April 1-11
• Time Dependent Models of Flares from Sagittarius A*
• Fifteen years of XMM-Newton and Chandra monitoring of Sgr A*: Evidence for a recent increase in the bright flaring rate
• Tilted black hole accretion disc models of Sagittarius A*: time-variable millimetre to near-infrared emission
• Particle Acceleration and the Origin of X-ray Flares in GRMHD simulations of Sgr A*
• An 8 hour characteristic time-scale in submillimetre light curves of Sagittarius A*
• Polarized Synchrotron Emissivities and Absorptivities for Relativistic Thermal, Power-Law, and Kappa Distribution Functions
• NuSTAR detection of high-energy X-ray emission and rapid variability from Sagittarius A* flares
• The mean infrared emission of SagittariusA*
• Fast Variability and mm/IR flares in GRMHD Models of Sgr A* from Strong-Field Gravitational Lensing
• Thermal X-Ray Iron Line Emission from the Galactic Center Black Hole Sagittarius A*
• ALMA and VLA measurements of frequency-dependent time lags in Sagittarius A*: evidence for a relativistic outflow
• Evolving Nonthermal Electrons in Simulations of Black Hole Accretion
• The Galactic Centre in the Far Infrared
• The impact of Faraday effects on polarized black hole images of Sagittarius A*
• Near-Infrared and X-ray Quasi-Periodic Oscillations in Numerical Models of Sgr A*
• The Pointing System of the Herschel Space Observatory. Description, Calibration, Performance and Improvements
• The impact of non-thermal electrons on event horizon scale images and spectra of Sgr A*
• The 492 GHz emission of Sgr A* constrained by ALMA
• Far Infrared Variability of Sagittarius A*: 25.5 Hours of Monitoring with $Herschel$

Cited by in corpus (24)

• First Sagittarius A* Event Horizon Telescope Results. VI: Testing the Black Hole Metric
• First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole
• First Sagittarius A* Event Horizon Telescope Results. II. EHT and Multi-wavelength Observations, Data Processing, and Calibration
• Rapid Variability of Sgr A* across the Electromagnetic Spectrum
• A parameter survey of Sgr A* radiative models from GRMHD simulations with self-consistent electron heating
• Constraining particle acceleration in Sgr A* with simultaneous GRAVITY, Spitzer, NuSTAR and Chandra observations
• The Flux Distribution of Sgr A*
• ALMA Observations of the Terahertz Spectrum of Sagittarius A*
• Effect of Electromagnetic Interaction on Galactic Center Flare Components
• Magnetic reconnection plasmoid model for Sagittarius A* flares
• Multiwavelength Light Curves of Two Remarkable Sagittarius A* Flares
• Time Variations in the Flux Density of Sgr A* at 230 GHz Detected with ALMA
• Probing spacetime and accretion model for the Galactic Center: Comparison of Kerr and dilaton black hole shadows
• Radio jet precession in M81*
• General relativistic effects and the near-infrared and X-ray variability of Sgr A* I
• Multi-wavelength Variability of Sagittarius A* in July 2019
• Fermi LAT observations of Sagittarius A*: Imaging Analysis
• Multi-wavelength torus-jet model for Sgr~A*
• Magnetic flux eruptions at the root of time-lags in low-luminosity AGN
• Observational Constraints on Direct Electron Heating in the Hot Accretion Flows in Sgr A* and M87*
• Mid-infrared extinction toward the Galactic center
• Compact stellar systems hosting an intermediate mass black hole: magnetohydrodynamic study of inflow-outflow dynamics
• Photometric Constraints on Intermediate-mass Black Holes in the Galactic Centre
• Radiative energy from a reconnection region around massive black hole