相关论文: M87: a cosmic laboratory for deciphering black hol…
The nearby elliptical galaxy M87 contains one of the only two supermassive black holes whose emission surrounding the event horizon has been imaged by the Event Horizon Telescope (EHT). In 2018, more than two dozen multi-wavelength (MWL)…
When surrounded by a transparent emission region, black holes are expected to reveal a dark shadow caused by gravitational light bending and photon capture at the event horizon. To image and study this phenomenon, we have assembled the…
It is believed that most giant elliptical galaxies possess nuclear black holes with masses in excess of $10^8\Msun$. Bondi accretion from the interstellar medium might then be expected to produce quasar-like luminosities from the nuclei of…
Jets are endemic to both Galactic solar mass and extragalactic supermassive black holes. A recent 86 GHz image of M\,87 shows a jet emerging from the accretion ring around a black hole, providing the first direct observational constraint on…
The Event Horizon Telescope (EHT) Collaboration has recently published the first horizon-scale images of the supermassive black holes M87* and Sgr A* and provided some first information on the physical conditions in their vicinity. The…
M87 is a giant elliptical galaxy located in the centre of the Virgo cluster, which harbours a supermassive black hole of mass 6.4x10^9 M_sun, whose activity is responsible for the extended (80 kpc) radio lobes that surround the galaxy. The…
In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly…
Recent advancements in high-resolution Very Long Baseline Interferometry (VLBI) have significantly improved our understanding of jet collimation near supermassive black holes in active galactic nuclei (AGNs), particularly in high-power…
We present the first simultaneous spectral energy distribution (SED) of M87 core at a scale of 0.4 arcsec ($\sim 32\, \rm{pc}$) across the electromagnetic spectrum. Two separate, quiescent, and active states are sampled that are…
The aim of this short paper is to motivate and encourage research in the field of Active Galactic Nuclei (AGN). Here we summarize the main open questions concerning the central engine. Is the central black hole rapidly spinning and can we…
M87 has been identified as a displaced supermassive black hole (SMBH) candidate. We investigated this possibility by a temporal analysis of twelve Adaptive-Optics assisted-VLT and HST images spanning twenty years. We found that the centre…
It has now become clear that the radio jet in the giant elliptical galaxy M87 must turn on very close to the black hole. This implies the efficient acceleration of leptons within the jet at scales much smaller than feasible by the typical…
The very latest observation of $M87$ supermassive black hole (BH) by the Event Horizon Telescope (EHT) provides the accretion onto BHs is an interesting study in the theory of gravity. We study the geodesics structure and accretion near a…
We analytically model stationary and axisymmetric active galactic nucleus jets, assuming energy conservation along each magnetic flux tube. Using very-long-baseline interferometry (VLBI) observations and published general relativistic…
We study Faraday rotation in the jet of M87 inside the Bondi radius using eight Very Long Baseline Array data sets, one at 8 GHz, four at 5 GHz, and three at 2 GHz. We obtain Faraday rotation measures (RMs) measured across the bandwidth of…
The central radio source in M87 provides the best opportunity to study jet formation because it has a large angular size for the gravitational radius of the black hole and has a bright jet that is well resolved by VLBI observations. We…
We explore an accretion model for low luminosity AGN (LLAGN) that attributes the low radiative output to a low mass accretion rate rather than a low radiative efficiency. In this model, electrons are assumed to drain energy from the ions as…
The study of jet launching in AGN is an important research method to better understand supermassive black holes (SMBHs) and their immediate surroundings. The main theoretical jet launching scenarios invoke either magnetic field lines…
X-rays are a critical wavelength for understanding supermassive black holes (SMBHs). X-rays probe the inner accretion flow, closest to the event horizon, where gas inspirals, releasing energy and driving black hole growth. This region also…
The observation of rapidly variable very high energy (VHE) gamma-rays from non-aligned active galactic nuclei (AGNs), as reported from M87, proves challenging for conventional theoretical acceleration and emission models. We re-examine the…