ASTRO 4 Final

The central region of a galaxy emitting extraordinarily high energy, powered by accretion (accumulated matter) onto a supermassive black hole.

Compactness of energy source, Broad spectral lines from gas moving at high velocities., Relativistic jets aligned with theoretical models of black hole magnetospheres.

The Broad Line Region (BLR) and dusty torus can block or reveal certain emissions depending on orientation.

Rapid fluctuations indicate a compact emission region. Timescales of variability are proportional to the size of the region, constrained by the light travel time formula t=R/c

Formed by twisted magnetic fields near the black hole, which accelerate charged particles outward.

Extreme luminosity, small size, rapid variability, emission across a wide range of wavelengths, and the presence of radio jets all point to a black hole as the energy source.

Emits up to a trillion times the Sun's energy.

Emission originates from a region smaller than a light-month.

Changes in brightness over short timescales (days or weeks).

Emits radiation from radio waves to gamma rays.

High-energy jets of matter ejected perpendicular to the accretion disk.

A supermassive black hole, accretion disk, broad line region (BLR), dusty torus, and relativistic jets.

Narrow streams of particles moving near the speed of light.

Short variability timescales suggest a compact region, with size limited by the formula t=R/ct = R/ct=R/c (time equals size divided by the speed of light).

Twisted magnetic fields near the black hole accelerate particles to near-light speeds, forming narrow jets that emit synchrotron radiation.

Apparent faster-than-light motion observed in relativistic jets. It occurs by a relativistic effect where a jet moving close to the speed of light and pointed toward Earth appears to move faster due to projection effects.

Galaxy mergers, bars in spiral galaxies, and cooling flows funnel gas to the central black hole.

Superluminal motion is an illusion caused by jets moving close to the speed of light toward us, compressing emission times.

Spiral galaxies use bars to drive gas inward, while elliptical galaxies rely on gas from galaxy mergers.

velocity = Hubble constant × distance. Hubble’s Law states that a galaxy’s recession velocity is proportional to its distance.

A larger hubble constant​ means a younger Universe.

Cosmological redshift is Caused by the stretching of space, light wavelengths. the Doppler Effect is from wavelength changes due to relative motion through space.

Uniform distribution of matter.

Radiation from the early Universe.

Indicators of cosmic evolution and expansion.

Type Ia supernovae have predictable brightness/luminosity, allowing accurate cosmic distance measurements.

A homogeneous and isotropic Universe, cosmic microwave background (CMB), and observations of distant galaxies and Type Ia supernovae.

The CMB comes from photons as faint radiation released 380,000 years after the Big Bang, when electrons and protons combine to form neutral hydrogen.

Extremely luminous AGN from the early Universe, representing the growth phase of supermassive black holes. They help us study early galaxy formation and cosmic conditions.

Abundant gas and frequent galaxy mergers in the dense early Universe fueled quasar activity.

they’re ripples in spacetime caused by accelerating massive objects, like merging black holes or neutron stars.

they stretch and compress due to spacetime distortion.

it confirmed black hole mergers and provided direct evidence of gravitational waves, validating Einstein's theory of general relativity.

it’s radiation emitted by black holes when virtual particle pairs near the event horizon separate, with one escaping as radiation.

it combines quantum mechanics and relativity to explain fundamental forces, dark energy, and the Universe’s evolution.

it causes the accelerated expansion of the Universe, driving the Big Freeze scenario.

Observations of dark energy and the Universe’s accelerating expansion.

Broad line regions can be obscured by the dusty torus depending on the viewing angle.

he compared the recession velocity and distance of galaxies to determine the relationship described by Hubble’s Law.

a redshift of 10% implies the Universe has expanded by 10% since the light left the galaxy.

it occurred everywhere in the Universe as space itself expanded

The CMB’s photons have been traveling through space, reaching us as faint microwave radiation.

By observing light that has taken billions of years to travel to us, we see these galaxies as they were in the distant past.

bc black holes of this size would require rapid growth unlikely to occur through stellar mass black hole mergers alone.

it uses light from the accretion disk bent around the black hole’s event horizon to create images of the shadow.

A phenomenon where tidal forces near a black hole stretch objects into long, thin shapes.

Through accretion disk emissions, gravitational interactions, and X-ray or infrared observations.

consists of particles with opposite charges and quantum numbers to their matter counterparts. positron is the antimatter of the electron