Introduction

2017 ◽  
Author(s):  
Nicholas Manton ◽  
Nicholas Mee
Keyword(s):  
Black Hole ◽  
Expanding Universe ◽  
Fundamental Particle ◽  
Supermassive Black Hole ◽  
The Earth ◽  
Visible Matter ◽  
Sentient Beings

We live in a fascinating world, bursting with remarkable phenomena on every scale. Our expanding universe is filled with trillions of galaxies, and a supermassive black hole inhabits the heart of each. Exploding stars seed the galaxies with the dust of life, and eight minutes away a blazing nuclear furnace releases the energy that keeps the Earth green, vibrant and full of life. Our marbled, watery globe may be unique, or one of many where sentient beings have evolved. At a smaller scale, all visible matter is made of just a few fundamental particle types, but these combine into more than a hundred different atoms that bond together in countless ways....

scholarly journals HOŘAVA–LIFSHITZ GRAVITY: TIGHTER CONSTRAINTS FOR THE KEHAGIAS–SFETSOS SOLUTION FROM NEW SOLAR SYSTEM DATA

2011 ◽  
Vol 20 (06) ◽  
pp. 1079-1093 ◽  
Author(s):  
L. IORIO ◽  
M. L. RUGGIERO
Keyword(s):  
Black Hole ◽  
Solar System ◽  
Lower Bounds ◽  
Modified Gravity ◽  
The Sun ◽  
Supermassive Black Hole ◽  
The Earth ◽  
Test Particles ◽  
The Galaxy ◽  
System Data

We analytically work out the perturbation Δρ induced by the Kehagias–Sfetsos (KS) spacetime solution of the Hořava–Lifshitz (HL) modified gravity at long distances on the two-body range ρ for a pair of test particles A and B orbiting the same mass M. We apply our results to the most recently obtained range residuals δρ for some planets of the solar system (Mercury, Mars, Saturn) ranged from the Earth to effectively constrain the dimensionless KS parameter ψ0 for the Sun. We obtain [Formula: see text] (Mercury), [Formula: see text] (Mars), and [Formula: see text] (Saturn). Such lower bounds are tighter than others existing in the literature by several orders of magnitude. We also preliminarily obtain [Formula: see text] for the system constituted by the S2 star orbiting the supermassive black hole (SBH) in the center of the galaxy.

Central kiloparsec of NGC 1326 observed with SINFONI

2020 ◽  
Vol 638 ◽  
pp. A53
Author(s):  
Nastaran Fazeli ◽  
Gerold Busch ◽  
Andreas Eckart ◽  
Françoise Combes ◽  
Persis Misquitta ◽  
...  
Keyword(s):  
Black Hole ◽  
Galaxy Evolution ◽  
Near Infrared ◽  
Velocity Fields ◽  
Molecular Gas ◽  
Nearby Galaxy ◽  
Stellar Content ◽  
Stellar Rotation ◽  
Supermassive Black Hole ◽  
Integral Field Spectrograph

Gas inflow processes in the vicinity of galactic nuclei play a crucial role in galaxy evolution and supermassive black hole growth. Exploring the central kiloparsec of galaxies is essential to shed more light on this subject. We present near-infrared H- and K-band results of the nuclear region of the nearby galaxy NGC 1326, observed with the integral-field spectrograph SINFONI mounted on the Very Large Telescope. The field of view covers 9″ × 9″ (650 × 650 pc2). Our work is concentrated on excitation conditions, morphology, and stellar content. The nucleus of NGC 1326 was classified as a LINER, however in our data we observed an absence of ionised gas emission in the central r ∼ 3″. We studied the morphology by analysing the distribution of ionised and molecular gas, and thereby detected an elliptically shaped, circum-nuclear star-forming ring at a mean radius of 300 pc. We estimate the starburst regions in the ring to be young with dominating ages of < 10 Myr. The molecular gas distribution also reveals an elongated east to west central structure about 3″ in radius, where gas is excited by slow or mild shock mechanisms. We calculate the ionised gas mass of 8 × 105 M⊙ completely concentrated in the nuclear ring and the warm molecular gas mass of 187 M⊙, from which half is concentrated in the ring and the other half in the elongated central structure. The stellar velocity fields show pure rotation in the plane of the galaxy. The gas velocity fields show similar rotation in the ring, but in the central elongated H2 structure they show much higher amplitudes and indications of further deviation from the stellar rotation in the central 1″ aperture. We suggest that the central 6″ elongated H2 structure might be a fast-rotating central disc. The CO(3–2) emission observations with the Atacama Large Millimeter/submillimeter Array reveal a central 1″ torus. In the central 1″ of the H2 velocity field and residual maps, we find indications for a further decoupled structure closer to a nuclear disc, which could be identified with the torus surrounding the supermassive black hole.

scholarly journals WISDOM project – VII. Molecular gas measurement of the supermassive black hole mass in the elliptical galaxy NGC 7052

2021 ◽  
Vol 503 (4) ◽  
pp. 5984-5996
Author(s):  
Mark D Smith ◽  
Martin Bureau ◽  
Timothy A Davis ◽  
Michele Cappellari ◽  
Lijie Liu ◽  
...  
Keyword(s):  
Black Hole ◽  
Hubble Space Telescope ◽  
Elliptical Galaxy ◽  
Continuum Emission ◽  
Molecular Gas ◽  
Supermassive Black Hole ◽  
Gas Kinematics ◽  
Long Baseline ◽  
Gas Measurement ◽  
Strong Gradient

ABSTRACT Supermassive black hole (SMBH) masses can be measured by resolving the dynamical influences of the SMBHs on tracers of the central potentials. Modern long-baseline interferometers have enabled the use of molecular gas as such a tracer. We present here Atacama Large Millimeter/submillimeter Array observations of the elliptical galaxy NGC 7052 at 0${^{\prime\prime}_{.}}$11 ($37\,$pc) resolution in the 12CO(2-1) line and $1.3\,$ mm continuum emission. This resolution is sufficient to resolve the region in which the potential is dominated by the SMBH. We forward model these observations, using a multi-Gaussian expansion of a Hubble Space Telescope F814W image and a spatially constant mass-to-light ratio to model the stellar mass distribution. We infer an SMBH mass of $2.5\pm 0.3\times 10^{9}\, \mathrm{M_\odot }$ and a stellar I-band mass-to-light ratio of $4.6\pm 0.2\, \mathrm{M_\odot /L_{\odot ,I}}$ (3σ confidence intervals). This SMBH mass is significantly larger than that derived using ionized gas kinematics, which however appears significantly more kinematically disturbed than the molecular gas. We also show that a central molecular gas deficit is likely to be the result of tidal disruption of molecular gas clouds due to the strong gradient in the central gravitational potential.

scholarly journals Morphological evolution of supermassive black hole merger hosts and multimessenger signatures

2021 ◽  
Vol 503 (3) ◽  
pp. 3629-3642
Author(s):  
Colin DeGraf ◽  
Debora Sijacki ◽  
Tiziana Di Matteo ◽  
Kelly Holley-Bockelmann ◽  
Greg Snyder ◽  
...  
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Star Formation ◽  
Morphological Evolution ◽  
Full Range ◽  
High Mass ◽  
Morphological Evidence ◽  
Galaxy Mergers ◽  
Host Galaxies ◽  
Supermassive Black Hole

ABSTRACT With projects such as Laser Interferometer Space Antenna (LISA) and Pulsar Timing Arrays (PTAs) expected to detect gravitational waves from supermassive black hole mergers in the near future, it is key that we understand what we expect those detections to be, and maximize what we can learn from them. To address this, we study the mergers of supermassive black holes in the Illustris simulation, the overall rate of mergers, and the correlation between merging black holes and their host galaxies. We find these mergers occur in typical galaxies along the MBH−M* relation, and that between LISA and PTAs we expect to probe the full range of galaxy masses. As galaxy mergers can trigger star formation, we find that galaxies hosting low-mass black hole mergers tend to show a slight increase in star formation rates compared to a mass-matched sample. However, high-mass merger hosts have typical star formation rates, due to a combination of low gas fractions and powerful active galactic nucleus feedback. Although minor black hole mergers do not correlate with disturbed morphologies, major mergers (especially at high-masses) tend to show morphological evidence of recent galaxy mergers which survive for ∼500 Myr. This is on the same scale as the infall/hardening time of merging black holes, suggesting that electromagnetic follow-ups to gravitational wave signals may not be able to observe this correlation. We further find that incorporating a realistic time-scale delay for the black hole mergers could shift the merger distribution towards higher masses, decreasing the rate of LISA detections while increasing the rate of PTA detections.

scholarly journals The ecology of the galactic centre: Nuclear stellar clusters and supermassive black holes

2019 ◽  
Vol 14 (S351) ◽  
pp. 80-83 ◽  
Author(s):  
Melvyn B. Davies ◽  
Abbas Askar ◽  
Ross P. Church
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Large Fraction ◽  
Galactic Nuclei ◽  
Supermassive Black Holes ◽  
Galactic Centre ◽  
Stellar Clusters ◽  
Stellar Cluster ◽  
Supermassive Black Hole ◽  
Multiple Clusters

AbstractSupermassive black holes are found in most galactic nuclei. A large fraction of these nuclei also contain a nuclear stellar cluster surrounding the black hole. Here we consider the idea that the nuclear stellar cluster formed first and that the supermassive black hole grew later. In particular we consider the merger of three stellar clusters to form a nuclear stellar cluster, where some of these clusters contain a single intermediate-mass black hole (IMBH). In the cases where multiple clusters contain IMBHs, we discuss whether the black holes are likely to merge and whether such mergers are likely to result in the ejection of the merged black hole from the nuclear stellar cluster. In some cases, no supermassive black hole will form as any merger product is not retained. This is a natural pathway to explain those galactic nuclei that contain a nuclear stellar cluster but apparently lack a supermassive black hole; M33 being a nearby example. Alternatively, if an IMBH merger product is retained within the nuclear stellar cluster, it may subsequently grow, e.g. via the tidal disruption of stars, to form a supermassive black hole.

Women Healing the Globe, Preserving the Tibetan Plateau

2021 ◽  
Vol 29 (3) ◽  
pp. 264-289
Author(s):  
Janice L. Poss
Keyword(s):  
Tibetan Plateau ◽  
Roman Catholic ◽  
The Tibetan Plateau ◽  
Rosemary Radford Ruether ◽  
Relevant Today ◽  
The Earth ◽  
Faith Traditions ◽  
Responsible Care ◽  
Exemplary Practice ◽  
Sentient Beings

The Tibetan Plateau’s Permafrost is melting at an alarming rate. Six of the world’s major rivers are sourced in the Tibetan Himalayas that are warming at a faster rate than the rest of the earth. If the temperature of the region continues to increase, the rivers will dry up and the earth will warm at an even faster rate. Buddha Yeshe Tsogyal (ye shes mTsho rgyal) (757–817 CE), long considered the Mother of Tibetan Tantric Buddhism, was the consort of Padmasambhava. She reached “complete liberation” or Nirvana in a single lifetime. Her stories are preserved in rman thar. Her life was an exemplary practice of compassion, responsible care, and non-violence toward all sentient beings and the world. Can we follow her proto-eco-feminist example? Can we build responsible care for our planet and humanity across disciplines and faith traditions? What does compassionate, non-violent Buddhist thought and Roman Catholic pastoral care bring to eco-feminism? Can an eco-feminist epistemology informed by Buddhist EcoDharma construct programs of sustainability into humanity’s excessive habits integrating science’s ability to quantify, with Buddha nature? Can Catholicism’s pastoral ability to show dependence on God, the peaceful, compassionate Creator of all allow us to see our dependence on God and our earth? Many women have already begun this work around the globe. In 2002, Rosemary Radford Ruether brought 16 women together from around the globe in Women Healing Earth: Third World Women on Ecology, Feminism, and Religion to tell us how they are doing it and succeeding. Each is highlighted here for their visions on how to heal the planet at the grassroots level. From their insights, this article explores their contributions as being still relevant today and adding new concerns about the dangers arising on the Tibetan Plateau. The article emphasizes their ideas, provides a warning and other ideas that collective activation might inspire to address climate change.

scholarly journals Null Geodesics and Strong Field Gravitational Lensing in a String Cloud Background

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
M. Sharif ◽  
Sehrish Iftikhar
Keyword(s):  
Black Hole ◽  
Gravitational Lensing ◽  
Galactic Center ◽  
Deflection Angle ◽  
Orbital Motion ◽  
Strong Field ◽  
Schwarzschild Black Hole ◽  
Field Limit ◽  
Null Geodesics ◽  
Supermassive Black Hole

This paper is devoted to studying two interesting issues of a black hole with string cloud background. Firstly, we investigate null geodesics and find unstable orbital motion of particles. Secondly, we calculate deflection angle in strong field limit. We then find positions, magnifications, and observables of relativistic images for supermassive black hole at the galactic center. We conclude that string parameter highly affects the lensing process and results turn out to be quite different from the Schwarzschild black hole.

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