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Optically violent variable quasars (OVV quasars) are characterized by their stable and unchanging brightness over time.
Answer: False
The defining characteristic of OVV quasars is their high variability in brightness, directly contradicting the notion of stable and unchanging luminosity.
Optically violent variable quasars (OVV quasars) are classified as a subtype of blazars, which are recognized for exhibiting energetic phenomena originating from active galactic nuclei.
Answer: True
OVV quasars are indeed classified as a subtype of blazars, which are known for their energetic phenomena originating from active galactic nuclei.
The significant variability observed in OVV quasars means their brightness can fluctuate by up to 50% within a period of one month.
Answer: False
While OVV quasars exhibit significant variability, the source indicates that fluctuations of up to 50% can occur within a single day, making the statement about a one-month period misleadingly slow.
The term 'Flat-Spectrum Radio Quasar' (FSRQ) is becoming less common, with 'OVV quasar' gaining popularity.
Answer: False
The source material indicates the opposite: the term 'Flat-Spectrum Radio Quasar' (FSRQ) is becoming more widely adopted, while terms like 'OVV quasar' are becoming less common.
OVV quasars exhibit weaker broad emission lines compared to BL Lac objects when observed at visible wavelengths.
Answer: False
At visible wavelengths, OVV quasars generally exhibit stronger broad emission lines compared to BL Lac objects.
The specific examples of OVV quasars provided in the source material include 3C 279 and S5 0014+81.
Answer: True
The source material explicitly lists two examples of OVV quasars: 3C 279 and S5 0014+81.
The provided image is a direct photograph of the OVV quasar 3C 279 taken by a powerful telescope.
Answer: False
The image is identified as an artist's impression of the OVV quasar 3C 279, not a direct photographic observation.
Cygnus X-1 is listed as a notable example of an optically violent variable quasar (OVV quasar).
Answer: False
Cygnus X-1 is a well-known X-ray binary system containing a black hole, but it is not listed as an example of an OVV quasar in the provided source material.
The source material explicitly states that OVV quasars are unrelated to Flat-Spectrum Radio Quasars (FSRQ).
Answer: False
The source material indicates that OVV quasars are largely unified with or considered subtypes of Flat-Spectrum Radio Quasars (FSRQ), suggesting a relationship rather than being unrelated.
The image of 3C 279 is described as an artist's impression, not a direct observation.
Answer: True
The image is identified as an artist's impression of the OVV quasar 3C 279, not a direct photographic observation.
What is the principal characteristic that defines an optically violent variable quasar (OVV quasar)?
Answer: High variability in brightness.
OVV quasars are fundamentally defined by their significant and rapid fluctuations in visible light brightness.
Which classification term is increasingly favored and gaining popularity for describing objects such as OVV quasars?
Answer: Flat-Spectrum Radio Quasar (FSRQ)
The term Flat-Spectrum Radio Quasar (FSRQ) is becoming the more widely adopted designation, with terms like OVV quasar becoming less prevalent.
In terms of their spectral characteristics observed at visible wavelengths, how do OVV quasars generally differ from BL Lac objects?
Answer: OVV quasars generally exhibit stronger broad emission lines.
A key distinction between OVV quasars and BL Lac objects, when observed in visible light, is that OVV quasars typically display more pronounced broad emission lines.
Which of the following celestial objects is explicitly listed as an example of an optically violent variable quasar (OVV quasar)?
Answer: 3C 279
The source material specifically identifies 3C 279 as an example of an OVV quasar.
What is the primary characteristic that distinguishes optically violent variable quasars (OVV quasars) from other types of quasars?
Answer: Their rapid and significant variability in visible light.
The defining feature of OVV quasars is their pronounced and rapid variability in brightness observed in visible light.
Which classification has largely unified with optically violent variable quasars (OVV quasars) and is becoming the more widely adopted term?
Answer: Flat-Spectrum Radio Quasar (FSRQ)
The term Flat-Spectrum Radio Quasar (FSRQ) is increasingly adopted, encompassing or unifying classifications such as OVV quasars.
According to the provided information, how do optically violent variable quasars (OVV quasars) generally compare to BL Lac objects concerning their broad emission lines?
Answer: OVV quasars have stronger lines.
OVV quasars are noted to exhibit stronger broad emission lines than BL Lac objects when observed at visible wavelengths.
Supermassive black holes are primarily linked to the formation of stellar-mass black holes through supernovae.
Answer: False
Supermassive black holes are distinct from stellar-mass black holes, which are primarily formed from the core collapse of massive stars during supernovae. Supermassive black holes likely form through different mechanisms, such as mergers or direct collapse.
The Tolman–Oppenheimer–Volkoff limit defines the maximum mass a neutron star can sustain before undergoing gravitational collapse into a black hole.
Answer: True
The Tolman–Oppenheimer–Volkoff limit represents the critical upper mass limit for a neutron star, beyond which it must collapse into a black hole due to gravity.
Stellar black holes are the largest category of black holes mentioned in terms of size classification.
Answer: False
Stellar black holes are distinct from intermediate-mass and supermassive black holes, which are significantly larger categories.
Which of the following is NOT listed as a type or size classification of black hole in the provided source material?
Answer: Pulsar black holes
The source material lists stellar, intermediate-mass, and supermassive black holes, among others, but 'pulsar black holes' are not mentioned as a classification.
What physical limit is mentioned in the context of stellar evolution leading to black hole formation?
Answer: The Tolman–Oppenheimer–Volkoff limit
The Tolman–Oppenheimer–Volkoff limit is specifically mentioned as the maximum mass a neutron star can sustain before collapsing into a black hole.
The Kerr metric is a mathematical framework used to describe the spacetime geometry of non-rotating, uncharged black holes.
Answer: False
The Kerr metric specifically describes the spacetime geometry of *rotating* black holes. The Schwarzschild metric is used for non-rotating, uncharged black holes.
The Schwarzschild metric is used to describe the spacetime geometry of rotating black holes.
Answer: False
The Schwarzschild metric describes the spacetime geometry of *non-rotating*, uncharged black holes. The Kerr metric is used for rotating black holes.
The Schwarzschild metric is employed to describe the spacetime geometry of a non-rotating, uncharged black hole.
Answer: True
The Schwarzschild metric is the fundamental solution in general relativity describing the spacetime geometry around a non-rotating, electrically neutral black hole.
The event horizon is the region around a black hole where the Penrose process can extract rotational energy.
Answer: False
The Penrose process, which extracts rotational energy from a black hole, occurs within the *ergosphere*, not the event horizon itself.
The ergosphere is a region external to a rotating black hole where spacetime itself is dragged along with the black hole's rotation.
Answer: True
The ergosphere is a region surrounding rotating black holes where the extreme gravity causes spacetime itself to be dragged along with the black hole's rotation.
Which mathematical metric is specifically employed to describe the spacetime geometry surrounding a rotating black hole?
Answer: Kerr metric
The Kerr metric is the standard solution in general relativity used to describe the spacetime geometry of a rotating black hole.
What is the significance of the Innermost Stable Circular Orbit (ISCO) in the context of black holes?
Answer: The smallest radius around a black hole where stable orbits are possible.
The ISCO represents the boundary within which stable circular orbits are no longer possible for massive particles, leading them to spiral into the black hole.
Hawking radiation is a theoretical process by which black holes gain mass from surrounding matter.
Answer: False
Hawking radiation is a theoretical process by which black holes *lose* mass over time, rather than gain it.
Spaghettification is a theoretical model proposed to explain the internal structure of black holes.
Answer: False
Spaghettification describes the physical effect of extreme tidal forces stretching an object vertically and compressing it horizontally as it approaches a black hole, not its internal structure.
The 'no-hair theorem' suggests that stable black holes can be described by numerous unique properties, including the composition of the matter that formed them.
Answer: False
The 'no-hair theorem' posits that stable black holes are characterized by only a few fundamental properties (mass, charge, angular momentum), losing all other distinguishing features or 'hair' from their formation.
The 'no-hair theorem' posits that a stable black hole can be fully characterized by which three fundamental properties?
Answer: Mass, electric charge, and angular momentum
According to the no-hair theorem, the only properties defining a stable black hole are its mass, electric charge, and angular momentum.
What is the principal implication of the 'no-hair theorem' concerning black holes?
Answer: Black holes are fundamentally simple objects characterized by only a few properties.
The theorem implies that black holes are remarkably simple, defined solely by mass, charge, and angular momentum, irrespective of their complex formation histories.
The phenomenon characterized by the vertical stretching and horizontal compression of an object due to extreme tidal forces near a black hole is known as:
Answer: Spaghettification
Spaghettification is the term used to describe the extreme stretching and compression of matter by tidal forces in the vicinity of a black hole.
Which related concept describes the process where a star is gravitationally disrupted by the extreme tidal forces exerted by a massive object, such as a black hole?
Answer: Tidal disruption events
Tidal disruption events occur when a celestial body, like a star, is torn apart by the intense gravitational tidal forces of a massive object.
Supermassive black holes are primarily linked to powering which of the following astrophysical phenomena?
Answer: Active Galactic Nuclei (AGN) and Quasars
Supermassive black holes are understood to be the central engines powering phenomena such as Active Galactic Nuclei (AGN) and quasars.
Which of these is listed as a notable black hole or related object?
Answer: TON 618
TON 618 is listed among the notable objects, representing a hyperluminous quasar powered by a supermassive black hole.
The black hole information paradox presents a theoretical problem concerning the potential loss of information that falls into a black hole, creating a conflict with fundamental principles of quantum mechanics.
Answer: True
The black hole information paradox is a significant theoretical challenge arising from the apparent contradiction between general relativity and quantum mechanics regarding the fate of information that enters a black hole.
The firewall paradox posits the potential existence of a high-energy 'firewall' at the event horizon of a black hole.
Answer: True
The firewall paradox suggests a high-energy 'firewall' might exist at the event horizon, challenging the smooth structure predicted by general relativity and potentially violating quantum principles.
What does the holographic principle, discussed as a theoretical issue, suggest about the information content of a region of space?
Answer: It can be represented on its lower-dimensional boundary.
The holographic principle proposes that the information content of a volume of space can be encoded on its boundary, analogous to a hologram.
Which theoretical issue suggests the potential existence of a high-energy barrier at the event horizon of a black hole?
Answer: The firewall paradox
The firewall paradox is the theoretical concept that proposes the existence of a high-energy barrier at the event horizon.
The membrane paradigm treats the event horizon, rather than the singularity, as a physical membrane with specific properties.
Answer: True
The membrane paradigm models the *event horizon* as a physical membrane with electromagnetic and thermal properties, not the singularity.
Gravastars are presented as standard models of black holes, identical in structure to those described by the Schwarzschild metric.
Answer: False
Gravastars are theoretical *alternatives* to standard black holes, proposed to avoid the singularity. They differ structurally from Schwarzschild black holes.
Sonic black holes are astrophysical objects that exhibit event horizons similar to gravitational black holes.
Answer: False
Sonic black holes are *physical analogs* that mimic black hole behavior, including event horizons, but they are not astrophysical objects in the same sense as gravitational black holes.
What is a gravastar proposed to be?
Answer: A theoretical alternative to a black hole that avoids a singularity.
A gravastar is a theoretical object proposed as an alternative to a black hole, characterized by its avoidance of a central singularity.
Which of the following is mentioned as a physical analog system that mimics black hole behavior?
Answer: Sonic black holes
Sonic black holes are presented as physical analog systems that exhibit behaviors similar to those of gravitational black holes.
Which of the following is presented as a theoretical alternative to a standard black hole, featuring a core of de Sitter vacuum?
Answer: Gravastar
The gravastar model proposes an alternative structure to a black hole, incorporating a de Sitter vacuum core.
Optical black holes and sonic black holes are described in the text as examples of:
Answer: Physical analogs for black holes.
Optical and sonic black holes serve as physical analogs, demonstrating black hole-like phenomena in different physical systems.
Fuzzballs, a concept arising from string theory, are proposed as a potential resolution to the black hole information paradox.
Answer: True
Fuzzballs are theoretical objects proposed within string theory that offer a potential resolution to the black hole information paradox by suggesting a non-singular structure.