Universe Builder - Part 1 - Cosmology

Cosmology - Universe Wide

Cosmology considers large structures and the universe as a whole.

Timeline

Ref: https://en.wikipedia.org/wiki/Chronology_of_the_universe#Tabular_summary
1 Ga = 1 billion years or giga-annum (10⁹ years)

Epoch	Time	Redshift	Temperature	Description
Radiation-dominated era	From inflation (~ 10−32 sec) ≈ 47 ka	> 3600	> 104 K	During this time, the energy density of massless and near-massless relativistic components such as photons and neutrinos, which move at or close to the speed of light, dominates both matter density and dark energy.
Matter-dominated era	47 ka ~ 9.8 Ga	3600 ~ 0.4	104 K ~ 4 K	During this time, the energy density of matter dominates both radiation density and dark energy, resulting in a decelerated metric expansion of space.
Dark-energy- dominated era	> 9.8 Ga	< 0.4	< 4 K	Matter density falls below dark energy density (vacuum energy), and expansion of space begins to accelerate. This time happens to correspond roughly to the time of the formation of the Solar System and the evolutionary history of life.
Anthropocene	13.8 Ga			You are Here
Stelliferous Era	150 Ma ~ 100 Ga	20 ~ −0.99	60 K ~ 0.03 K	The time between the first formation of Population III stars until the cessation of star formation, leaving all stars in the form of degenerate remnants.
Far future	> 100 Ga	< −0.99	< 0.1 K	The Stelliferous Era will end as stars eventually die and fewer are born to replace them, leading to a darkening universe. Various theories suggest a number of subsequent possibilities. Assuming proton decay, matter may eventually evaporate into a Dark Era (heat death). Alternatively the universe may collapse in a Big Crunch. Other suggested ends include a false vacuum catastrophe or a Big Rip as possible ends to the universe.

You can see more at https://www.sciencealert.com/timeline-shows-the-entire-history-of-the-universe-and-how-it-ends.

Composition and Structure of the Universe

The observable Universe is bigger than 13.8 billion light years as the universe is expanding.

In physical cosmology, structure formation is the formation of galaxies, galaxy clusters and larger structures from small early density fluctuations. This is best assessed by The cosmic microwave background (CMB, CMBR). 

The most famous experiment is probably the NASA Cosmic Background Explorer (COBE) satellite that orbited in 1989–1996 and which detected and quantified the large scale anisotropies at the limit of its detection capabilities. In June 2001, NASA launched a second CMB space mission, WMAP, to make much more precise measurements of the large scale anisotropies over the full sky. WMAP used symmetric, rapid-multi-modulated scanning, rapid switching radiometers to minimize non-sky signal noise. A third space mission, the ESA (European Space Agency) Planck Surveyor, was launched in May 2009 and performed an even more detailed investigation until it was shut down in October 2013.

Based on the 2013 Planck data, the universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. On 5 February 2015, new data was released by the Planck mission, according to which the age of the universe is 13.799±0.021 billion years old and the Hubble constant was measured to be 67.74±0.46 (km/s)/Mpc.[82]

Ref: https://en.wikipedia.org/wiki/File:Observable_Universe_with_Measurements_01.png	Ref: https://photojournal.jpl.nasa.gov/catalog/PIA16874 Ref: https://www.nasa.gov/images/content/735683main_pia16873-full_full.jpg
Ref: PABLO CARLOS BUDASSI
Ref: PABLO CARLOS BUDASSI	Ref: Sloan Digital Sky Survey

Distance Measurements

1 AU  = 1.495978707×10¹¹ m  = Distance from Earth to Sun
1 light year = 9.460 730 472 5808 x 10¹⁵ m
1 parcec = 3.26156 light years =  1/tan(1/3600 deg) * 1 AU = 3.0856775814913673×10¹⁶ m = distance at which 1 au subtends an angle of one arcsecond
1 z = red shift

Mass Measurement

 M_☉= Mass Sun

Reference

Chronology of the universe - Wikipedia
Observable universe - Wikipedia
Cosmic microwave background - Wikipedia

Universe Structure

Structure	Number	Size	Number of Galxies	Description
Observable Universe			2 x 1012
Galaxy Filaments/Super Clusters	~10 million	160 to 260 (520?) million light-years		Structure of super clusters
Laniakea Supercluster		520 million light-years	100,000 galaxies
Virgo Supercluster		110 million light-years	47,000 galaxies.
Local Group		3 megaparsecs (10 million light-years; 9×1022 metres),	~ 89 galaxies

ref: Galaxy filament - Wikipedia, Supercluster - Wikipedia, Local Group - Wikipedia, Medium - How Much Of The Unobservable Universe Will We Someday Be Able To See?

Galaxy Filaments

ref: Galaxy filament - Wikipedia
In cosmology, galaxy filaments (subtypes: supercluster complexes, galaxy walls, and galaxy sheets) are the largest known structures in the universe, consisting of walls of gravitationally bound galaxy superclusters. These massive, thread-like formations can reach 80 megaparsecs h⁻¹ (or of the order of 160 to 260 million light-years) and form the boundaries between large voids.

ref: The Universe within 500 million light years, showing the nearest galaxy walls.

ref: 1280px-Large-scale_structure_of_light_distribution_in_the_universe

Super Clusters

A supercluster is a large group of smaller galaxy clusters or galaxy groups;[1] it is among the largest known structures of the universe. The Milky Way is part of the Local Group galaxy group (which contains more than 54 89 galaxies), which in turn is part of the Virgo Supercluster, which is part of the Laniakea Supercluster.[2] The large size and low density of superclusters means that they, unlike clusters, expand with the Hubble expansion. The number of superclusters in the observable universe is estimated to be 10 million.

Local Group

ref: Local Group - Wikipedia

Spiral galaxies
name	type	Distance	Diameter	Mass	Stars	notes
Andromeda Galaxy (M31, NGC 224)	SA(s)b	2.73 million light-years	220 kly	(1.5±0.5)×1012 M☉	ca. 1012.	Largest galaxy in the group
Milky Way Galaxy	SBbc	NA	175±25 kly	(1.54±0.1)×1012 M☉	(2.5±1.5)×1011.	Second largest galaxy in the group, which may or may not be the most massive galaxy of the group.
Triangulum Galaxy (M33, NGC 598)	SA(s)cd	2.73 million light-years	60 kly	5×1010 M☉	4×1010	Third largest, only unbarred spiral galaxy and possible satellite of the Andromeda Galaxy.
Magellanic Spiral Galaxies
Large Magellanic Cloud (LMC)	Irr/SB(s)m	160,000 light-years	14 kly	1×1010 M☉		Fourth largest member of the group, satellite of Milky Way and only Magellanic Spiral Galaxy in the local group
NGC 3109	SB(s)m					Member of Antlia-Sextans Group
Elliptical galaxies
M32 (NGC 221)	E2					Satellite of the Andromeda Galaxy, shows signs of a supermassive black hole
Irregular galaxies
Wolf–Lundmark–Melotte (WLM, DDO 221)	Ir+
IC 10	KBm or Ir+
Small Magellanic Cloud (SMC, NGC 292)	SB(s)m pec			7 × 109 M☉		Satellite of Milky Way, 6th largest galaxy in the local group
Canis Major Dwarf	Irr					Satellite of Milky Way
Pisces Dwarf (LGS3)	Irr					Possible satellite of the Triangulum Galaxy
IC 1613 (UGC 668)	IAB(s)m V
Phoenix Dwarf	Irr
Leo A (Leo III)	IBm V
Aquarius Dwarf (DDO 210)	IB(s)m					Distance 3.2 million light years. Quite isolated in space, membership to Local Group established in 1999.[12]
SagDIG (Sagittarius Dwarf Irregular Galaxy)	IB(s)m V					Most remote from barycenter member thought to be in the Local Group.[12]
NGC 6822 (Barnard's Galaxy)	IB(s)m IV-V
Pegasus Dwarf (Pegasus Dwarf Irregular, DDO 216)	Irr
UGC 4879 (VV124)	IAm					One of the most isolated galaxies in Local Group. Situated at the edge of the Local Group.
Sextans A (UGCA 205)	Ir+V					Member of Antlia-Sextans Group
Sextans B (UGC 5373)	Ir+IV-V					Member of Antlia-Sextans Group
Leo P	Irr					Member of Antlia-Sextans Group

Astrophysics

Astrophysics creates physical theories of small to medium-size structures in the universe

Types of Galxies - Hubble Sequence

Elliptical galaxies have relatively smooth, featureless light distributions and appear as ellipses in photographic images. They are denoted by the letter E, followed by an integer n representing their degree of ellipticity in the sky. By convention, n is ten times the ellipticity of the galaxy, rounded to the nearest integer, where the ellipticity is defined as $ e = 1 - {{a}\over {b}} $ for an ellipse with semi-major and semi-minor axes of lengths a and b respectively

Lenticulars and given the symbol S0. These galaxies consist of a bright central bulge, similar in appearance to an elliptical galaxy, surrounded by an extended, disk-like structure. Unlike spiral galaxies, the disks of lenticular galaxies have no visible spiral structure and are not actively forming stars in any significant quantity.

A spiral galaxy consists of a flattened disk, with stars forming a (usually two-armed) spiral structure, and a central concentration of stars known as the bulge. Roughly half of all spirals are also observed to have a bar-like structure, with the bar extending from the central bulge, and the arms begin at the ends of the bar. In the tuning-fork diagram, the regular spirals occupy the upper branch and are denoted by the letter S, while the lower branch contains the barred spirals, given the symbol SB.

• Sa (SBa) – tightly wound, smooth arms; large, bright central bulge
• Sb (SBb) – less tightly wound spiral arms than Sa (SBa); somewhat fainter bulge
• Sc (SBc) – loosely wound spiral arms, clearly resolved into individual stellar clusters and nebulae; smaller, fainter bulge
• Sd (SBd) – very loosely wound, fragmentary arms; most of the luminosity is in the arms and not the bulge

Irregular Galaxies do not fit into the Hubble sequence as they have no regular structure (either disk-like or ellipsoidal). Hubble defined two classes of irregular galaxy:

• Irr I galaxies have asymmetric profiles and lack a central bulge or obvious spiral structure; instead they contain many individual clusters of young stars
• Irr II galaxies have smoother, asymmetric appearances and are not clearly resolved into individual stars or stellar clusters

Taking the classification from Revised Shapley-Ames Catalog of Bright Galaxies (https://ned.ipac.caltech.edu/level5/Shapley_Ames/frames.html)

Type	Count	Percentage
E	172	13.5%
S0/SB0	156	12.3%
S	662	52.0%
SB	242	19.0%
Irregular	41	3.2%
	1273	100%

Milky Way

datasets

Calalogue	Published	Stars	Coverage
Hipparcos Catalogue	1997	118,200
Tycho Catalogue	1997	1 million
Tycho-2 Catalogue	2000	2.6 million
Sloan Digital Sky Survey	2008	48 million	1/3 sky
Gaia Data Release 1	2016	1,142,679,769
Gaia Data Release 2	2018	1,692,919,135