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The dataset generation failed
Error code:   DatasetGenerationError
Exception:    CastError
Message:      Couldn't cast
id: string
area: string
subject: string
area_title: string
subject_title: string
section: string
register: string
half: string
source_file: string
messages: list<item: struct<role: string, content: string>>
  child 0, item: struct<role: string, content: string>
      child 0, role: string
      child 1, content: string
prompt_source: string
n_turns: int64
n_chars: int64
est_tokens: int64
text: string
to
{'id': Value('string'), 'area': Value('string'), 'subject': Value('string'), 'area_title': Value('string'), 'subject_title': Value('string'), 'section': Value('string'), 'register': Value('string'), 'half': Value('string'), 'source_file': Value('string'), 'text': Value('string'), 'n_chars': Value('int64'), 'est_tokens': Value('int64')}
because column names don't match
Traceback:    Traceback (most recent call last):
                File "/usr/local/lib/python3.14/site-packages/datasets/builder.py", line 1816, in _prepare_split_single
                  for key, table in generator:
                                    ^^^^^^^^^
                File "/src/services/worker/src/worker/job_runners/config/parquet_and_info.py", line 613, in wrapped
                  for item in generator(*args, **kwargs):
                              ~~~~~~~~~^^^^^^^^^^^^^^^^^
                File "/usr/local/lib/python3.14/site-packages/datasets/packaged_modules/json/json.py", line 343, in _generate_tables
                  self._cast_table(pa_table, json_field_paths=json_field_paths),
                  ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                File "/usr/local/lib/python3.14/site-packages/datasets/packaged_modules/json/json.py", line 132, in _cast_table
                  pa_table = table_cast(pa_table, self.info.features.arrow_schema)
                File "/usr/local/lib/python3.14/site-packages/datasets/table.py", line 2369, in table_cast
                  return cast_table_to_schema(table, schema)
                File "/usr/local/lib/python3.14/site-packages/datasets/table.py", line 2297, in cast_table_to_schema
                  raise CastError(
                  ...<3 lines>...
                  )
              datasets.table.CastError: Couldn't cast
              id: string
              area: string
              subject: string
              area_title: string
              subject_title: string
              section: string
              register: string
              half: string
              source_file: string
              messages: list<item: struct<role: string, content: string>>
                child 0, item: struct<role: string, content: string>
                    child 0, role: string
                    child 1, content: string
              prompt_source: string
              n_turns: int64
              n_chars: int64
              est_tokens: int64
              text: string
              to
              {'id': Value('string'), 'area': Value('string'), 'subject': Value('string'), 'area_title': Value('string'), 'subject_title': Value('string'), 'section': Value('string'), 'register': Value('string'), 'half': Value('string'), 'source_file': Value('string'), 'text': Value('string'), 'n_chars': Value('int64'), 'est_tokens': Value('int64')}
              because column names don't match
              
              The above exception was the direct cause of the following exception:
              
              Traceback (most recent call last):
                File "/src/services/worker/src/worker/job_runners/config/parquet_and_info.py", line 1369, in compute_config_parquet_and_info_response
                  parquet_operations, partial, estimated_dataset_info = stream_convert_to_parquet(
                                                                        ~~~~~~~~~~~~~~~~~~~~~~~~~^
                      builder, max_dataset_size_bytes=max_dataset_size_bytes
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                  )
                  ^
                File "/src/services/worker/src/worker/job_runners/config/parquet_and_info.py", line 948, in stream_convert_to_parquet
                  builder._prepare_split(split_generator=splits_generators[split], file_format="parquet")
                  ~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                File "/usr/local/lib/python3.14/site-packages/datasets/builder.py", line 1683, in _prepare_split
                  for job_id, done, content in self._prepare_split_single(
                                               ~~~~~~~~~~~~~~~~~~~~~~~~~~^
                      gen_kwargs=gen_kwargs, job_id=job_id, **_prepare_split_args
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                  ):
                  ^
                File "/usr/local/lib/python3.14/site-packages/datasets/builder.py", line 1869, in _prepare_split_single
                  raise DatasetGenerationError("An error occurred while generating the dataset") from e
              datasets.exceptions.DatasetGenerationError: An error occurred while generating the dataset

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id
string
area
string
subject
string
area_title
string
subject_title
string
section
string
register
string
half
string
source_file
string
text
string
n_chars
int64
est_tokens
int64
1faf678cbc397cb8
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
The Origin of Life and What Life Requires
prose
mtp
astronomy_space/astrobiology.txt
## The Origin of Life and What Life Requires Astrobiology asks whether life exists beyond Earth, and every part of the question depends on premises drawn from a single example. This is the field's defining epistemic problem: with a sample size of one, it is impossible to distinguish the requirements of life in general...
497
134
93897bf8a71e354a
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
The Origin of Life and What Life Requires
prose
mtp
astronomy_space/astrobiology.txt
What appears genuinely general is a short list. Life requires a source of free energy maintaining a system away from thermodynamic equilibrium, a medium in which chemistry can occur, and a set of elements capable of forming complex structures. Carbon's capacity for stable four-bonded chains and rings is unusual and not...
630
170
4adf485ac77f787c
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
The Origin of Life and What Life Requires
prose
calib
astronomy_space/astrobiology.txt
The origin of life on Earth occurred early — within a few hundred million years of conditions permitting it — which is suggestive but not conclusive about how likely the transition is. The major open questions concern the sequence: whether metabolism or replication came first, where the energy gradient was, and how the...
582
157
93cde860ab609448
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
The Origin of Life and What Life Requires
table
calib
astronomy_space/astrobiology.txt
Requirements and origins: the sample-size problem one example; requirements and contingencies are confounded free energy a gradient maintained away from equilibrium a solvent water on Earth; ammonia and hydrocarbons as alternatives complex chemistry carbon's four-b...
1,216
328
fe8b47b5351e7355
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
The Origin of Life and What Life Requires
qa
mtp
astronomy_space/astrobiology.txt
Q: Searches for life often target liquid water specifically. The strongest justification is: A. Life requires water as a matter of physical law B. Water is an excellent solvent with unusual properties, it is abundant, and it is what our only known example uses — so it is the best-motivated search target, though not ...
699
188
647c12a0763aba5a
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Habitability and Extreme Environments
prose
mtp
astronomy_space/astrobiology.txt
## Habitability and Extreme Environments The habitable zone is defined as the orbital range where a planet with an Earth-like atmosphere could sustain liquid water at its surface. It is a useful first filter and it is much narrower than the actual range of habitable conditions, because it considers only surface water ...
458
123
5f080755ad052ae0
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Habitability and Extreme Environments
prose
calib
astronomy_space/astrobiology.txt
Stellar type shapes habitability substantially. Small cool stars are the most numerous, have very long lifetimes, and place their habitable zone close in, which makes planets there easier to detect and also tidally locked, with permanent day and night sides. Whether that is fatal depends on atmospheric heat transport, ...
588
158
0eee087e1411c5b4
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Habitability and Extreme Environments
prose
mtp
astronomy_space/astrobiology.txt
The study of terrestrial extremophiles has repeatedly widened the envelope of conditions known to support life. Organisms grow above the boiling point of water at pressure, below its freezing point in brines, at pH values spanning most of the scale, at radiation doses that shatter chromosomes, and kilometres undergroun...
565
152
21275e4589115cb3
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Habitability and Extreme Environments
table
mtp
astronomy_space/astrobiology.txt
Habitability: habitable zone surface liquid water from starlight; a first filter only the narrowness ignores subsurface and non-stellar heat sources tidal heating orbital flexing as an energy source; independent of distance from the star radiogenic heating decay in th...
1,440
389
dfdaa5948a7bd960
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Solar System Targets
prose
calib
astronomy_space/astrobiology.txt
## Solar System Targets Mars is the most accessible target and the case for past habitability is strong. The surface records long-lived standing water, clay minerals requiring sustained aqueous alteration, and river and lake sediments. The present surface is hostile — thin dry atmosphere, ionizing radiation, strongly ...
560
151
1cf29ea82f9dac81
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Solar System Targets
prose
calib
astronomy_space/astrobiology.txt
Europa and Enceladus are the icy moon targets, both with subsurface liquid water oceans in contact with a rocky floor, which is the configuration that supplies chemical energy. Enceladus is extraordinary because it vents ocean material into space through south polar plumes, and a spacecraft can therefore sample the oce...
538
145
58ab2b55d34be005
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Solar System Targets
prose
mtp
astronomy_space/astrobiology.txt
Titan is the outlier and the more interesting case conceptually, because it tests whether the water assumption is a requirement or a parochialism. It has a dense nitrogen atmosphere, an active methane cycle with rain, rivers, and lakes of liquid hydrocarbon, abundant complex organic chemistry produced in its atmosphere...
592
160
67429007b5ad71fb
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Solar System Targets
table
mtp
astronomy_space/astrobiology.txt
Solar system targets: Mars strong evidence of past surface water; hostile present surface, shielded subsurface the oxidizing surface perchlorates and radiation destroying organics sample return the decisive step; the required instruments cannot be flown Europa ...
1,370
370
f8928eaf107af60a
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Biosignatures and Exoplanet Atmospheres
prose
mtp
astronomy_space/astrobiology.txt
## Biosignatures and Exoplanet Atmospheres A biosignature is an observable that is better explained by life than by anything else, and the qualifier carries all the weight. Every proposed biosignature has abiotic pathways, so the inference is comparative rather than definitive, and it depends on context — the same mol...
393
106
f368faa551b1de2b
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Biosignatures and Exoplanet Atmospheres
prose
calib
astronomy_space/astrobiology.txt
Atmospheric disequilibrium is the strongest general principle. An atmosphere containing gases that should react with each other requires continuous replenishment, and life is one mechanism that maintains such disequilibrium. Earth's simultaneous abundance of oxygen and methane is the standard example, since they react ...
388
104
14760cbcf6da2b65
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Biosignatures and Exoplanet Atmospheres
prose
calib
astronomy_space/astrobiology.txt
Exoplanet atmospheres are characterized by transmission spectroscopy: starlight passing through the atmosphere during transit acquires absorption features from its constituents. The signal is extremely small, the observations are photon-starved, and clouds and hazes mute the features, which is why atmospheric detection...
521
140
719dce60bd547abb
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Biosignatures and Exoplanet Atmospheres
table
calib
astronomy_space/astrobiology.txt
Biosignatures and detection: the definition better explained by life than by anything else abiotic pathways every candidate has them; context decides disequilibrium coexisting gases that should react; the strongest general argument oxygen and methane the terrestrial exam...
1,390
375
a59e376d9c9c3536
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Technosignatures and Inference
prose
calib
astronomy_space/astrobiology.txt
## Technosignatures and Inference Searching for technology rather than biology changes the target from chemistry to artifacts. Narrowband radio emission remains the canonical signature because such signals do not occur naturally and propagate efficiently across interstellar distances. Optical pulses, waste heat in the...
498
134
b0f249f047c56031
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Technosignatures and Inference
prose
calib
astronomy_space/astrobiology.txt
The Fermi question — given the age and size of the galaxy, why no evidence — has many proposed resolutions and no way to choose among them. Life may be extremely rare. The transition to complex life may be the bottleneck. Technological civilizations may be short-lived. Interstellar travel and communication may be less ...
606
163
2077fd126a0e9806
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Technosignatures and Inference
prose
mtp
astronomy_space/astrobiology.txt
The Drake formulation is often misread as an estimate and is better understood as a decomposition. Its value is in identifying which terms are measurable and which are not. The astronomical terms — star formation rate, planet frequency, habitable-zone occurrence — have moved from speculation to measurement over the pas...
544
147
54f5784787392270
astronomy_space
astrobiology
Astronomy and Space
Astrobiology
Technosignatures and Inference
table
mtp
astronomy_space/astrobiology.txt
Technosignatures and inference: narrowband radio the canonical signature; no natural analogue optical pulses nanosecond laser pulses outshining the star briefly waste heat thermodynamically unavoidable for large energy use industrial pollutants long-lived artificial molecules in an atmosphe...
1,479
399
230f89ce61d1d42f
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Radiation, Spectra, and Stellar Atmospheres
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
## Radiation, Spectra, and Stellar Atmospheres Nearly everything known about the universe beyond the solar system arrived as electromagnetic radiation, so interpreting that radiation is the foundational skill of astrophysics. A blackbody is an idealized perfect absorber and emitter whose spectrum depends only on tempe...
413
111
bfa13afcce68da5e
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Radiation, Spectra, and Stellar Atmospheres
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Two laws govern blackbody emission. Wien's displacement law states that the wavelength of peak emission is inversely proportional to temperature, so hot objects are blue and cool ones red — this is why a star's colour measures its surface temperature and why infrared astronomy studies cool objects. The Stefan-Boltzmann...
775
209
cf282a86c5f878a9
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Radiation, Spectra, and Stellar Atmospheres
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Spectral lines carry more information than the continuum. Kirchhoff's laws describe when each type appears: a hot dense source produces a continuous spectrum, a hot diffuse gas produces emission lines, and a cool diffuse gas in front of a continuum source produces absorption lines. A stellar spectrum shows absorption l...
449
121
066ba4a952171dad
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Radiation, Spectra, and Stellar Atmospheres
table
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Radiation quantities: Wien's law lambda_peak = 2.898e-3 m K / T Stefan-Boltzmann F = sigma T^4; sigma = 5.67e-8 W/(m^2 K^4) luminosity L = 4 pi R^2 sigma T^4 inverse square F = L / (4 pi d^2) Doppler shift delta_lambda / lambda = v / c (non-relativistic) cosm...
686
185
707a0acf70244066
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Radiation, Spectra, and Stellar Atmospheres
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Stellar spectral classification, the sequence O B A F G K M, orders stars by surface temperature from about 40,000 K down to under 3,000 K, extended by L, T, and Y for brown dwarfs. The classification is historical — originally alphabetical by hydrogen line strength before temperature was understood — which is why the ...
736
198
53271419853ca740
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Radiation, Spectra, and Stellar Atmospheres
qa
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Q: Star A has twice the surface temperature of star B and half the radius. The ratio of their luminosities L_A/L_B is: A. 1 B. 4 C. 8 D. 16 Reasoning: L is proportional to R^2 T^4. The radius factor contributes (1/2)^2 = 1/4 and the temperature factor 2^4 = 16, giving 16/4 = 4. Answer: B.
295
79
b3b8c0bf5eee5cc7
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Structure and Energy Generation
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
## Stellar Structure and Energy Generation A star is a self-gravitating ball of plasma in hydrostatic equilibrium: at every radius, the outward pressure gradient balances the inward weight of the material above. This single condition, combined with an energy source, an energy transport mechanism, and an equation of st...
550
148
ff00663a06943c11
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Structure and Energy Generation
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
The energy source is nuclear fusion in the core, where temperature and density are high enough to overcome the Coulomb barrier between nuclei. Even at fifteen million kelvin, the core of the Sun, thermal energies are far below the barrier height, and fusion proceeds only through quantum tunnelling — the reaction rate i...
694
187
ff556782d5efabaf
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Structure and Energy Generation
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Hydrogen burning proceeds by two channels whose relative importance depends on temperature. The proton-proton chain dominates below about 18 million kelvin and powers the Sun; its rate scales roughly as T^4. The CNO cycle uses carbon, nitrogen, and oxygen as catalysts, dominates above that temperature in more massive s...
527
142
56ade6cbfb28f54f
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Structure and Energy Generation
table
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Stellar structure essentials: hydrostatic equilibrium dP/dr = -G M(r) rho(r) / r^2 energy transport radiation where the opacity permits, convection where the temperature gradient becomes too steep mass-luminosity L proportional to M^3.5 on the main sequence main-...
853
230
3fb529811db7dc29
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Structure and Energy Generation
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
The mass-luminosity relation combined with fuel supply produces the most consequential result in stellar astrophysics. Luminosity scales as roughly the 3.5 power of mass, while available fuel scales linearly with mass, so lifetime scales as M divided by M^3.5, or M^-2.5. A star ten times the Sun's mass has about three ...
731
197
64857a55a8cab474
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
The Hertzsprung-Russell Diagram
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
## The Hertzsprung-Russell Diagram Plotting luminosity against surface temperature for a population of stars does not produce a scatter; it produces well-defined sequences, and understanding why is understanding stellar evolution. About ninety percent of stars lie along the main sequence running from hot and luminous ...
542
146
cc3f92c3d2b59f3e
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
The Hertzsprung-Russell Diagram
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Above and to the right lie the giants and supergiants — cool but enormously luminous, which by L = 4 pi R^2 sigma T^4 requires very large radii. Below and to the left lie the white dwarfs, hot but very faint, hence very small. These regions are sparsely populated not because such stars are rare in an absolute sense but...
468
126
e48e9e2d468946aa
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
The Hertzsprung-Russell Diagram
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
The diagram's greatest practical use is dating star clusters. Every star in a cluster formed at approximately the same time from the same material, so they differ only in mass. Massive stars exhaust their core hydrogen first and leave the main sequence, so as a cluster ages, the main sequence burns down from the top. T...
657
177
ab5d43807aafe0b3
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
The Hertzsprung-Russell Diagram
table
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
HR diagram regions: main sequence core hydrogen burning; 90% of stars; mass sequence subgiant branch hydrogen exhausted in core, shell burning begins red giant branch inert helium core contracts, envelope expands enormously horizontal branch core helium burning; the red giant's stable successor asy...
745
201
3d38e37190602ebc
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
The Hertzsprung-Russell Diagram
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
The instability strip is where variable stars pulsate, and its most important inhabitants are the Cepheids. A Cepheid's pulsation period is tightly correlated with its luminosity, so measuring the period gives the absolute magnitude, and comparing with the apparent magnitude gives the distance. This period-luminosity r...
594
160
548c3e3ab2dbb74e
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
## Stellar Death and Compact Objects How a star dies is determined almost entirely by its mass, and the thresholds are sharp because they correspond to physical limits rather than to gradual transitions.
204
55
097efdb4be5e5369
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Stars below about eight solar masses end as white dwarfs. After exhausting core hydrogen and then helium, they lack the mass to compress the carbon-oxygen core to carbon-ignition temperature. The outer envelope is expelled as a planetary nebula — a misleading name from the era when their small discs resembled planets —...
639
172
5802c5d9f955a71d
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
The Chandrasekhar limit, about 1.4 solar masses, is the maximum mass electron degeneracy pressure can support. It is derived rather than measured: as mass increases, the electrons become relativistic, and the pressure they supply grows too slowly with density to resist further compression. A white dwarf pushed past thi...
705
190
6db61ccfd4011552
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Stars above about eight solar masses proceed through successive burning stages — carbon, neon, oxygen, silicon — each faster than the last, building an onion-shell structure with an iron core at the centre. Iron is where fusion stops, because it has the highest binding energy per nucleon, so fusing it consumes rather t...
618
167
8e6cb98b4b82a721
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
table
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Stellar endpoints by initial mass: < 0.08 M_sun brown dwarf; never ignites hydrogen 0.08 - 0.5 red dwarf; fully convective, lifetimes exceeding a trillion years 0.5 - 8 red giant, planetary nebula, white dwarf (C-O core) 8 - 20 core-collapse supernova, neutron star 20 - 40 ...
628
169
61def04232024c08
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Neutron stars are the densest observable matter, packing more than a solar mass into a radius of about ten kilometres, so a teaspoon of neutron star material would weigh as much as a mountain. They conserve the angular momentum and magnetic flux of their progenitor cores, which is why they rotate hundreds of times per ...
617
166
e35001f5e6a54c22
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Black holes form when even neutron degeneracy fails. The event horizon at the Schwarzschild radius, 2GM/c^2, is not a surface but a boundary beyond which no path leads outward — three kilometres for a solar mass, and about ten million kilometres for the supermassive black hole at the centre of a large galaxy. Black hol...
578
156
52c9efc98f50a521
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
transcript
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
[user] How do we actually know the mass of a black hole we can't see? [assistant] tool_call astro.mass_methods({"object_class": "black_hole"}) [tool] {"methods": [{"name": "orbital_dynamics", "applies": "companion or stellar orbits", "precision": "high"}, {"name": "gravitational_waves", "applies": "mergers", "precision...
715
193
ba03ed694e5093dc
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
Orbital dynamics is the most direct and the most trustworthy. If anything orbits the black hole — a companion star in an X-ray binary, or the stars circling the galactic centre — then Kepler's third law gives the enclosed mass from the orbital period and semi-major axis. The stars near the Milky Way's centre have been ...
506
136
3a495b426b57fd46
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Gravitational waves give a remarkably clean measurement for merging pairs. The waveform's frequency evolution during inspiral depends on a specific combination of the two masses called the chirp mass, and the full waveform through merger and ringdown constrains the individual masses and spins. This is measuring the mas...
370
100
ed212ff2b67d7284
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
For distant supermassive black holes, indirect methods take over. Reverberation mapping measures the light-travel-time delay between variations in the central continuum and the response of surrounding gas, giving the radius of that gas; combined with its orbital velocity from line widths, that gives the mass — good to ...
685
185
fbe2b80f75aca190
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Stellar Death and Compact Objects
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
And for the two nearest supermassive examples, direct horizon-scale imaging now resolves the shadow, whose angular size scales with mass and provides an independent check consistent with the dynamical measurements.
214
57
ba405bb1105c60e0
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Galaxies and Cosmology
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
## Galaxies and Cosmology Galaxies are gravitationally bound systems of stars, gas, dust, and dark matter. Hubble's morphological classification divides them into ellipticals, spirals, and irregulars, and the scheme is descriptive rather than evolutionary despite the "early" and "late" type terminology it inherited. E...
644
174
f61b4e4b383a11be
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Galaxies and Cosmology
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
The rotation curves of spiral galaxies provided the first strong evidence for dark matter. Orbital velocity should decline with radius outside the visible mass, following Kepler's laws as it does in the solar system. Instead, measured rotation curves stay flat far beyond the visible disc, implying that mass continues t...
730
197
f7275ccc3ec0cd72
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Galaxies and Cosmology
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Modern cosmology rests on the observation that the universe is expanding. Hubble's law relates recession velocity to distance, and running the expansion backward gives a hot dense beginning about 13.8 billion years ago. The cosmic microwave background is the relic radiation released when the universe cooled enough for ...
580
156
3d8e608de4e9d595
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Galaxies and Cosmology
table
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Cosmological quantities: Hubble's law v = H_0 d; H_0 ≈ 67-73 km/s/Mpc, and the disagreement between measurement methods is an unresolved tension age of universe ~13.8 Gyr CMB temperature 2.725 K, blackbody to extraordinary precision composition ~5% or...
799
215
fec669fe524f688e
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Galaxies and Cosmology
prose
calib
astronomy_space/astrophysics_and_stellar_evolution.txt
Dark energy is the name for whatever drives the observed acceleration of the expansion, discovered in 1998 through Type Ia supernovae appearing fainter — and therefore more distant — than a decelerating universe would place them. It behaves like a constant energy density of empty space with negative pressure, which in ...
691
186
5daff285d0a8a27d
astronomy_space
astrophysics_and_stellar_evolution
Astronomy and Space
Astrophysics and Stellar Evolution
Galaxies and Cosmology
prose
mtp
astronomy_space/astrophysics_and_stellar_evolution.txt
The recurring lesson of the last century of cosmology is that the constituents we understand are the minority. Ordinary matter — everything made of atoms, including every star, planet, and person — is about five percent of the energy content of the universe. The rest is inferred entirely from its gravitational effects,...
694
187
39253f4891738f43
astronomy_space
cosmology
Astronomy and Space
Cosmology
Expansion and Cosmological Models
prose
mtp
astronomy_space/cosmology.txt
## Expansion and Cosmological Models Cosmology applies general relativity to the universe as a whole, and it becomes tractable because of an assumption that observation supports: on scales above a few hundred million light-years, the universe is homogeneous and isotropic — the same everywhere and in every direction. T...
486
131
ab4ed73374b14eb5
astronomy_space
cosmology
Astronomy and Space
Cosmology
Expansion and Cosmological Models
prose
calib
astronomy_space/cosmology.txt
Hubble's observation that galaxies recede with velocity proportional to distance is the foundational measurement. The relation is not a velocity through space but an expansion of space itself, which matters for interpretation: there is no centre from which expansion proceeds, every observer sees the same recession patt...
483
130
e7ba0d34a4536c86
astronomy_space
cosmology
Astronomy and Space
Cosmology
Expansion and Cosmological Models
prose
calib
astronomy_space/cosmology.txt
Cosmological redshift follows from the same picture and is distinct from a Doppler shift. As light travels, space expands, and the wavelength stretches proportionally. The redshift therefore measures the ratio of the scale factor now to the scale factor when the light was emitted, which is why redshift is a direct meas...
406
109
00cc369a414b4274
astronomy_space
cosmology
Astronomy and Space
Cosmology
Expansion and Cosmological Models
table
calib
astronomy_space/cosmology.txt
Foundational relations: cosmological principle homogeneous and isotropic on large scales Hubble's law v = H_0 d; H_0 ≈ 67-73 km/s/Mpc scale factor a(t); a = 1 today redshift 1 + z = 1/a at emission Hubble time 1/H_0 ≈ 14 Gyr; a rough age estimate Friedmann...
1,065
287
cda5d968e99f077d
astronomy_space
cosmology
Astronomy and Space
Cosmology
Expansion and Cosmological Models
prose
mtp
astronomy_space/cosmology.txt
The observable universe's radius exceeding the speed of light times its age is a point that generates persistent confusion and has a straightforward explanation. Light emitted 13.8 billion years ago has travelled for that duration, and the space it crossed has expanded while it travelled, so the emitting material is no...
458
123
3436ac9731f88f99
astronomy_space
cosmology
Astronomy and Space
Cosmology
Expansion and Cosmological Models
qa
mtp
astronomy_space/cosmology.txt
Q: A galaxy is observed at redshift z = 3. The universe has expanded by what factor since that light was emitted? A. 3 B. 4 C. 1/3 D. 9 Reasoning: The relation is 1 + z = a_now / a_then, so 1 + 3 = 4. The universe was one quarter of its present size, and all wavelengths have been stretched by a factor of four. An...
328
88
f0211ff9cd0db0ab
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Hot Big Bang and Nucleosynthesis
prose
calib
astronomy_space/cosmology.txt
## The Hot Big Bang and Nucleosynthesis Running the expansion backward implies that the universe was denser and hotter in the past, and the hot Big Bang model traces the consequences. At early times the universe was a dense plasma in thermal equilibrium, and as it expanded and cooled, successive processes fell out of ...
480
129
377dd6ed7aed2dbb
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Hot Big Bang and Nucleosynthesis
prose
calib
astronomy_space/cosmology.txt
The sequence of epochs is set by the temperature at which each interaction becomes too slow relative to the expansion to maintain equilibrium. Within the first second, the weak interactions maintaining the neutron-to-proton ratio froze out, fixing that ratio at roughly one to six. Between about one second and a few min...
568
153
956fc1933e999095
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Hot Big Bang and Nucleosynthesis
prose
calib
astronomy_space/cosmology.txt
Big Bang nucleosynthesis produced the light elements and is one of the model's strongest quantitative successes. Essentially all the helium-4 in the universe, about 24 percent by mass, was made in those few minutes, along with trace deuterium, helium-3, and lithium-7. The predicted abundances depend on a single free pa...
667
180
e66d4c94be587158
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Hot Big Bang and Nucleosynthesis
table
calib
astronomy_space/cosmology.txt
The hot Big Bang timeline: < 1e-32 s inflation (proposed); exponential expansion 1e-6 s quarks bind into protons and neutrons 1 s neutrinos decouple; the neutron-proton ratio freezes 1-200 s nucleosynthesis; helium-4, deuterium, helium-3, lithium-7 ~50,000 yr matte...
943
254
cff3cee211c86662
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Hot Big Bang and Nucleosynthesis
prose
mtp
astronomy_space/cosmology.txt
The lithium problem deserves mention because it is an honest anomaly. Predicted primordial lithium-7 exceeds what is measured in the oldest stars by roughly a factor of three, a discrepancy well outside the quoted uncertainties. Proposed explanations include stellar processes depleting lithium in those stars, unknown n...
595
160
b350e9410c373c47
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Cosmic Microwave Background
prose
mtp
astronomy_space/cosmology.txt
## The Cosmic Microwave Background The microwave background is relic radiation from recombination, when the universe became transparent. Its discovery in 1965 as an unexplained excess noise in a radio antenna decisively favoured the hot Big Bang over the steady-state alternative, which had no mechanism to produce a th...
337
91
33bd1f0a36ff3788
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Cosmic Microwave Background
prose
calib
astronomy_space/cosmology.txt
Its spectrum is the most perfect blackbody ever measured, matching a temperature of 2.7255 kelvin with deviations below a part in ten thousand. That precision is itself informative: it means the early universe was in thermal equilibrium and that no substantial energy was injected afterward, which constrains a range of ...
337
91
0b91e847be66e70d
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Cosmic Microwave Background
prose
mtp
astronomy_space/cosmology.txt
The temperature fluctuations are the payload. After removing the dipole caused by our own motion, the residual variations are about one part in a hundred thousand, and their statistical pattern encodes the composition and geometry of the universe. The fluctuations arose from acoustic oscillations in the pre-recombinati...
480
129
cf71c4e34f3764d9
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Cosmic Microwave Background
prose
calib
astronomy_space/cosmology.txt
The power spectrum of these fluctuations — the amplitude as a function of angular scale — shows a series of peaks whose positions and relative heights are precise diagnostics. The first peak's angular position measures the geometry, because it corresponds to a known physical size at a known distance and the observed an...
669
180
7f40e51b27df6262
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Cosmic Microwave Background
table
calib
astronomy_space/cosmology.txt
CMB observables: temperature 2.7255 K; blackbody to better than 1 part in 10^4 dipole ~3.4 mK; our motion at ~370 km/s relative to the CMB frame fluctuations ~1 part in 10^5 after dipole removal angular power spectrum amplitude versus angular scale; the primary dataset first...
1,076
290
2518441f8c36af7d
astronomy_space
cosmology
Astronomy and Space
Cosmology
The Cosmic Microwave Background
prose
mtp
astronomy_space/cosmology.txt
The consistency between independent probes is what makes the concordance model credible. The baryon density inferred from CMB peak ratios agrees with the value inferred from primordial deuterium, which is a completely independent measurement of a completely different phenomenon at a completely different epoch. The matt...
528
142
aa84776d3a6efad0
astronomy_space
cosmology
Astronomy and Space
Cosmology
Structure Formation, Dark Matter, and Dark Energy
prose
calib
astronomy_space/cosmology.txt
## Structure Formation, Dark Matter, and Dark Energy Structure grew from the tiny density fluctuations visible in the CMB through gravitational instability: overdense regions attract more matter, becoming more overdense. The growth rate is set by the competition between gravity and expansion, and it is slow — density ...
517
139
33d06581a53b3809
astronomy_space
cosmology
Astronomy and Space
Cosmology
Structure Formation, Dark Matter, and Dark Energy
prose
calib
astronomy_space/cosmology.txt
That timeline is impossible without dark matter, and this is one of the strongest arguments for it. Ordinary matter was coupled to radiation until recombination, so its fluctuations could not grow during that entire period — radiation pressure erased them. Dark matter, not interacting with radiation, began growing much...
548
148
21dd8ae920b46c65
astronomy_space
cosmology
Astronomy and Space
Cosmology
Structure Formation, Dark Matter, and Dark Energy
prose
mtp
astronomy_space/cosmology.txt
The evidence for dark matter comes from several independent phenomena at different scales. Galaxy rotation curves stay flat far beyond the visible disc rather than declining as Kepler's laws would require. Velocity dispersions in galaxy clusters imply far more mass than the luminous content. Gravitational lensing maps ...
665
179
7708270cdf31867d
astronomy_space
cosmology
Astronomy and Space
Cosmology
Structure Formation, Dark Matter, and Dark Energy
table
mtp
astronomy_space/cosmology.txt
Dark sector evidence and properties: rotation curves flat far beyond the luminous disc cluster dynamics velocity dispersions imply excess mass gravitational lensing maps mass directly; exceeds visible matter CMB peaks require non-baryonic matter structure formation growth timelin...
1,268
342
48b197a5a5b766f5
astronomy_space
cosmology
Astronomy and Space
Cosmology
Structure Formation, Dark Matter, and Dark Energy
prose
mtp
astronomy_space/cosmology.txt
Dark energy's problem is theoretical rather than observational. A cosmological constant is the simplest explanation, corresponds to a constant energy density of the vacuum, and fits the data. Quantum field theory's naive estimate of the vacuum energy exceeds the observed value by something between fifty and a hundred a...
746
201
b0ec3ca8aad0b546
astronomy_space
cosmology
Astronomy and Space
Cosmology
Inflation and Open Questions
prose
mtp
astronomy_space/cosmology.txt
## Inflation and Open Questions Inflation proposes a brief period of exponential expansion in the first fraction of a second, and it was introduced to solve three problems in the standard hot Big Bang. The horizon problem is that regions of the CMB separated by more than about a degree could never have been in causal ...
685
185
6aee2602a8b79f24
astronomy_space
cosmology
Astronomy and Space
Cosmology
Inflation and Open Questions
prose
mtp
astronomy_space/cosmology.txt
Exponential expansion addresses all three with one mechanism. A region small enough to have been in causal contact is inflated to encompass the entire observable universe, explaining the uniformity. Any curvature is stretched flat, as the surface of an inflating balloon becomes locally flatter. And any pre-existing rel...
360
97
ece8c98333fc27e1
astronomy_space
cosmology
Astronomy and Space
Cosmology
Inflation and Open Questions
prose
mtp
astronomy_space/cosmology.txt
Inflation's most consequential feature is one it was not designed to provide: quantum fluctuations during the inflationary period are stretched to macroscopic scales and become the seed density perturbations from which all structure grew. This makes the specific statistical properties of the CMB fluctuations a predicti...
635
171
a30969659e2cd818
astronomy_space
cosmology
Astronomy and Space
Cosmology
Inflation and Open Questions
table
mtp
astronomy_space/cosmology.txt
Open questions: what is dark matter no confirmed detection despite decades of increasingly sensitive experiments what is dark energy the cosmological constant fits and is not explained the Hubble tension early-universe and late-universe measurements of the ...
1,203
325
42d85f55d29b171d
astronomy_space
cosmology
Astronomy and Space
Cosmology
Inflation and Open Questions
prose
calib
astronomy_space/cosmology.txt
The Hubble tension is the most active current disagreement and deserves the closing word. Measurements of the expansion rate from the CMB, extrapolated forward using the standard model, give roughly 67 kilometres per second per megaparsec. Direct measurements using the local distance ladder — Cepheids calibrating Type ...
868
234
a46d4aaf80d6ae0e
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Radiation Mechanisms
prose
mtp
astronomy_space/high_energy_astrophysics.txt
## Radiation Mechanisms High-energy astrophysics studies the most energetic processes in the universe, and interpreting what is observed requires knowing which physical process produced the radiation. The spectrum's shape is the primary diagnostic, because each mechanism produces a characteristic form that persists ac...
354
95
4533dd0a1728d983
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Radiation Mechanisms
prose
calib
astronomy_space/high_energy_astrophysics.txt
Thermal emission from an optically thick source is a blackbody, whose spectrum depends only on temperature. The peak wavelength moves inversely with temperature, so a source peaking in X-rays is at millions of kelvin. Thermal bremsstrahlung — braking radiation from electrons deflected by ions in a hot ionized gas — pro...
444
120
738558c5a10c0986
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Radiation Mechanisms
prose
mtp
astronomy_space/high_energy_astrophysics.txt
Synchrotron radiation comes from relativistic electrons spiralling in a magnetic field, and it produces a power-law spectrum rather than a thermal one because the electron energy distribution is itself a power law. This is the signature of non-thermal particle acceleration, and its presence establishes that some proces...
508
137
96053f93835fc33e
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Radiation Mechanisms
prose
mtp
astronomy_space/high_energy_astrophysics.txt
Inverse Compton scattering upscatters low-energy photons to high energy when they encounter relativistic electrons, which is the reverse of ordinary Compton scattering where a high-energy photon loses energy to an electron. It is how the highest-energy photons in many sources are produced, and the synchrotron self-Comp...
484
130
3af61408b7598bb3
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Radiation Mechanisms
table
calib
astronomy_space/high_energy_astrophysics.txt
Radiation mechanisms and their signatures: blackbody optically thick thermal; peak set by temperature alone bremsstrahlung hot ionized gas; flat with an exponential cutoff synchrotron relativistic electrons in a magnetic field; power law, polarized; establishes non...
1,202
324
56fbf6aecaf83e6e
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Radiation Mechanisms
prose
mtp
astronomy_space/high_energy_astrophysics.txt
The iron K-alpha line deserves particular attention because it is the most direct probe of strong gravity available. Iron fluoresces at a known rest energy, and a line produced in an accretion disc close to a black hole is broadened by Doppler shifts from orbital motion and skewed by gravitational redshift, producing a...
548
148
6941cbf17c975549
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Radiation Mechanisms
qa
mtp
astronomy_space/high_energy_astrophysics.txt
Q: A source shows a power-law spectrum extending over several decades in frequency, with significant linear polarization. The emission mechanism is most likely: A. Blackbody B. Synchrotron radiation from relativistic electrons in a magnetic field C. Thermal bremsstrahlung D. Atomic line emission Reasoning: A blackbody ...
668
180
a7a56257c2920b21
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Accretion
prose
calib
astronomy_space/high_energy_astrophysics.txt
## Accretion Accretion onto a compact object is the most efficient energy-release process known apart from matter-antimatter annihilation, and it powers most high-energy sources. Material falling toward a compact object releases gravitational potential energy, and the efficiency depends on how deep into the potential ...
620
167
b0d88be189a27405
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Accretion
prose
mtp
astronomy_space/high_energy_astrophysics.txt
Angular momentum is the obstacle that makes accretion structured rather than radial. Infalling material almost always has some angular momentum, so it cannot fall directly in and instead settles into an orbiting disc. Accretion then requires transporting angular momentum outward so that material can move inward, and id...
608
164
4dabdedcfcff2de2
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Accretion
prose
mtp
astronomy_space/high_energy_astrophysics.txt
The Eddington limit sets the maximum steady accretion rate. As accretion luminosity rises, the outward radiation pressure on infalling material grows, and at the Eddington luminosity it balances gravity so that further accretion is halted. The limit is proportional to the accretor's mass, which means a given source has...
565
152
24bb9e3e32102bf1
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Accretion
table
calib
astronomy_space/high_energy_astrophysics.txt
Accretion physics: efficiency ~10% for a neutron star, 6-32% for a black hole depending on spin; fusion is ~0.7% angular momentum the obstacle; requires outward transport for inward flow magnetorotational instability the transport mechanism; magnetic fields in ...
1,443
390
4cc91ebfadf75df4
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Accretion
prose
mtp
astronomy_space/high_energy_astrophysics.txt
The light-crossing argument deserves emphasis because it constrains source sizes without resolving them. A source cannot vary coherently on a timescale shorter than light takes to cross it, because different parts could not coordinate. A source varying on a timescale of milliseconds is therefore smaller than a light-mi...
530
143
7cf08bfbb5105547
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Compact Object Systems and Transients
prose
calib
astronomy_space/high_energy_astrophysics.txt
## Compact Object Systems and Transients X-ray binaries consist of a compact object accreting from a companion star, and they divide by the companion's mass in a way that determines the accretion mechanism. High-mass systems have a massive companion whose strong stellar wind is captured, giving persistent emission. Lo...
533
144
ffa812daae79b6a2
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Compact Object Systems and Transients
prose
mtp
astronomy_space/high_energy_astrophysics.txt
Distinguishing a neutron star from a black hole accretor is done by the presence or absence of a surface. A neutron star has one, so material accumulating on it eventually ignites in a thermonuclear flash producing a type I X-ray burst, and its rotating magnetic field can produce pulsations. A black hole has neither, s...
506
136
21293b0e2ef150dc
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Compact Object Systems and Transients
prose
mtp
astronomy_space/high_energy_astrophysics.txt
Supernovae divide into two physically distinct classes despite a spectroscopic classification that predates the understanding. Core-collapse supernovae occur when a massive star's iron core exceeds its degeneracy limit and collapses, with the resulting neutrino burst and rebound ejecting the envelope. Thermonuclear sup...
582
157
f777a43478521b1f
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Compact Object Systems and Transients
table
calib
astronomy_space/high_energy_astrophysics.txt
Compact objects and transients: high-mass X-ray binary wind accretion from a massive companion; persistent low-mass X-ray binary Roche lobe overflow; often transient type I X-ray burst thermonuclear flash on a neutron star surface; proves a surface exists pulsations ...
1,596
431
65d6c116f22036bd
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Compact Object Systems and Transients
prose
calib
astronomy_space/high_energy_astrophysics.txt
The 2017 neutron star merger is worth stating as a case because it settled several questions at once. Gravitational waves and a short gamma-ray burst arrived within two seconds, confirming that compact object mergers produce short bursts and constraining the speed of gravitational waves to match light to within one par...
670
181
be714a360b862279
astronomy_space
high_energy_astrophysics
Astronomy and Space
High-Energy Astrophysics
Active Galactic Nuclei and Jets
prose
calib
astronomy_space/high_energy_astrophysics.txt
## Active Galactic Nuclei and Jets An active galactic nucleus is a supermassive black hole accreting at a rate producing luminosity comparable to or exceeding the host galaxy's stars. The energy source is accretion rather than fusion, which is established by the efficiency required — the luminosity and the variability...
404
109
End of preview.

Broad-Domain Calibration & Instruction Supplement

~1M tokens of hand-authored text across 192 subjects in 9 areas, built to serve three jobs from one source: quantization calibration, MTP draft-head training (on a disjoint half), and light instruction tuning.

Version 0.1.0 · built 2026-08-09T17:45:53

split rows tokens~ size contents
corpus 5,536 969,606 5.4 MB raw authored samples + provenance; carries the calib/mtp half label
instruct 5,536 1,084,399 6.4 MB the same samples as chat-format prompt/response pairs

Topic distribution

area subjects samples tokens~ share
data_science_ml 27 861 148,041 15.3%
software_web 24 699 118,985 12.3%
humanities_business 24 633 116,425 12.0%
math 22 614 106,933 11.0%
physics 21 616 106,368 11.0%
embedded_hardware 19 571 99,046 10.2%
earth_life_sciences 19 520 97,693 10.1%
generative_art 19 539 90,941 9.4%
astronomy_space 17 483 85,174 8.8%
total 192 5,536 969,606 100%

Sample registers

register samples share
prose 4,245 76.7%
table 971 17.5%
qa 224 4.0%
transcript 96 1.7%

Disjoint halves

Every row carries half, a deterministic, non-overlapping assignment (see below). Filter on it; do not re-split.

half samples intended use
calib 2,704 quantization calibration (imatrix / AWQ / GPTQ)
mtp 2,832 MTP draft-head training

What this is for

A quantization calibration corpus is only as good as its coverage: llama-imatrix, AWQ and GPTQ all decide which weights matter from the activations a corpus produces, so whatever the corpus never exercises gets quantized on the assumption that it does not matter. The usual mixes — wiki text plus whatever logs happen to be available — are narrow in a way that is invisible until the quant is worse at something the corpus never covered.

This is a deliberately broad supplement, hand-authored across 9 areas and 192 subjects, to sit alongside a domain corpus rather than replace it. It was written to serve three jobs from one source:

  1. Quantization calibration — feed the calib half to llama-imatrix / AWQ / GPTQ.
  2. MTP draft-head training — train on the mtp half, next-token.
  3. Light instruction tuning — the instruct split, already in chat format.

The two halves are disjoint, on purpose

Every corpus row carries half, either calib or mtp. The assignment is deterministic and the two sets never overlap. This matters for a specific reason: a draft head trained on the same text used to calibrate the quant it drafts for would show an inflated acceptance rate, because part of what you would be measuring is memorization rather than draft quality. Keeping them apart is what makes an MTP acceptance number mean something.

The split is seeded per source file, not globally, so adding new subjects later never reshuffles the existing assignment — anything already calibrated or trained on stays valid.

How it was written

Hand-authored, one file per subject, in four deliberately mixed registers so the activation statistics are not all from one kind of text:

register what it is
prose expository explanation under a section heading
table indented term/definition reference blocks — dense, low-redundancy token patterns
qa exam-style question with options, reasoning, and a stated answer
transcript short illustrative [user] / [assistant] / [tool] dialogues

There are no raw chat-control tokens anywhere in the text (<|im_start|> and friends are linted against). That is deliberate: llama-perplexity has no --parse-special, so a marker embedded in the text tokenizes as a control token on one stack and as plain BPE on the other, which quietly makes PPL/KLD numbers incomparable. This corpus is safe to use as an eval file.

Using it

Calibration corpus — write the calib half out as flat text:

from datasets import load_dataset

ds = load_dataset("pearsonkyle/broad-domain-supplement", split="corpus")
calib = ds.filter(lambda r: r["half"] == "calib")
with open("corpus.broad.calib.txt", "w") as f:
    f.write("\n\n".join(calib["text"]))
llama-imatrix -m model-F16.gguf -f corpus.broad.calib.txt -o imatrix.gguf -c 4096

Interleave it with your in-domain corpus rather than concatenating: a token-budgeted calibrator samples the file, and a large block at the head can eat the whole budget.

MTP draft-head training — the disjoint half, next-token:

mtp = ds.filter(lambda r: r["half"] == "mtp")
text = "\n\n".join(mtp["text"])      # ~500k tokens

Instruction tuning — already chat-shaped:

from transformers import AutoTokenizer

inst = load_dataset("pearsonkyle/broad-domain-supplement", split="instruct")
tok = AutoTokenizer.from_pretrained("<your-model>")
rendered = tok.apply_chat_template(inst[0]["messages"], tokenize=False)

# authored prompts only (the question was written as a question, not templated):
authored = inst.filter(lambda r: r["prompt_source"] == "authored")

Filtering by topic — every row carries area and subject:

ml = ds.filter(lambda r: r["area"] == "data_science_ml")

Read this before using instruct

The instruct split's prompts come from two different places and the difference matters:

  • prompt_source: "authored" (~6%) — the qa and transcript rows. The question or user turn was written as a prompt. These are genuine instruction data.
  • prompt_source: "templated" (~94%) — the prose and table rows. The source text was written as continuous exposition, and the prompt is generated from the section heading and subject using a small set of templates. The responses are hand-written; the questions are not.

Templated prompts are fine for light instruction tuning and for teaching a model to answer topically on demand. They are repetitive by construction, and a model trained on them heavily will learn the template. If you want prompt diversity, filter to authored, rewrite the prompts, or mix this with a real instruction set — do not treat all 5.5k rows as if a person wrote 5.5k distinct questions. This is stated plainly because a dataset that quietly presents templated prompts as authored ones is the kind of thing that is discovered later, in results.

Caveats

  • Token counts are estimates. est_tokens uses a measured 3.70 chars/token ratio, not a real tokenizer. Expect a few percent of drift; recount with your own tokenizer if it matters. Two figures in the table differ for real reasons rather than by mistake: instruct totals more than corpus because it counts the generated prompts as well as the responses, and both sit slightly under the ~1.0M raw-file figure because section headers, the per-file metadata block, and blank separator lines are not part of any sample.
  • Single author, single voice. One person wrote all of it, so it is stylistically consistent in a way a scraped corpus is not. Good for controlled calibration, and it means the corpus does not represent stylistic diversity — do not use it to measure that.
  • Breadth over depth. Each subject is a competent overview at roughly 5k tokens, not expert-level treatment. It is written to exercise vocabulary and reasoning patterns across many domains, which is what calibration needs; it is not a reference text.
  • transcript tool calls were never executed. They are illustrative dialogues written to look like tool use, kept as literal assistant text rather than lifted into a structured tool_calls field, because presenting authored text as a captured trace would be misleading.
  • No claim is made that the content is error-free. It is a written corpus, not a verified one.

Row schema

Shared by both splits:

field meaning
id stable content hash of the sample
area, subject directory-level topic and subject file (e.g. physics / quantum_information)
area_title, subject_title human-readable forms
section the ## Section heading the sample sits under
register prose / table / qa / transcript — how it is written
half calib or mtp — disjoint. Filter on this; do not re-split
source_file path within calibration_supplements/broad/
n_chars, est_tokens size; tokens are a 3.70 chars/token estimate

corpus split adds:

field meaning
text the sample as authored, section heading included

instruct split adds:

field meaning
messages chat-format turns (user / assistant, plus tool for transcripts)
prompt_source authored (the prompt is from the source) or templated (generated from the heading — see the note above)
n_turns message count

Reproducing

Generated with Quant-Tuner; see docs/ternary_qat.md for the end-to-end pipeline and src/quant_tuner/datasets/ for the exact builder used to publish this.

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