Galaxy Formation and Evolution  

Formation > s.a. chaotic systems; cosmic strings; dark matter; fluids; inflationary phenomenology.
* Criteria: A theory has to explain the blackbody nature and isotropy of the microwave background.
* Theory and simulations: 2008, It is believed that galaxies were assembled via chaotic hierarchical mergers between massive cold dark matter halos, in which baryonic star forming matter was embedded; 2009, Some simulations indicate galaxies primarily formed as a result of intensive cosmic streams of cold gas (mostly hydrogen) and not primarily from galactic mergers; 2010, Simulations show a first rapid phase at z > 2 with in-situ star formation, and a second, extended phase at z < 3 with accretion of ex-situ stars.
* Primary mechanisms: Protogalaxies can form from growth of primordial fluctuations, or aggregation of material around cosmic string hoops or dark matter; A protogalaxy forms a galaxy if the energy dissipation time (by radiation) is smaller than the gravitational collapse time, otherwise it is too hot to collapse.
* Secondary mechanisms: Triggered by shock waves from supernovas; Tidal interactions and mergers play an important role in determining the kind of galaxy.
* Biasing: Characterized by the degenerate parameter combination β = Ω0.6/b, or just the linear bias parameter b, the ratio of the fluctuation amplitudes of the galaxy and mass distributions.
@ Books: Longair 08; Binney & Tremaine 08; Mo et al 10 [and evolution].
@ Reviews: Ellis Nat-ap/98; McGaugh ap/98-conf; Kauffmann & van den Bosch SA(02)jun; van den Bergh PASP(02)ap; Dekel ap/04-conf [scales]; Schombert ap/04-conf; Avila-Reese ap/06-ln; van Dokkum & Quadri a0704-proc [evolution and environment]; Palouš RAJ-a0708-ln; Combes a0909-conf; Geach SA(11)may; news sci(11)sep [simulations]; Silk et al a1312-ln; Conselice ARAA(14)-a1403 [evolution over cosmic time].
@ Structure formation: Padmanabhan IAU-ap/95; Brandenberger ap/95; Hu & Eisenstein PRD(99)ap/98; Silk AIP(04)ap [and dark matter]; Ostriker & Naab PT(12)aug [concordance cosmological model].
@ First galaxies: Macchetto & Dickinson SA(97)may; Baugh & French pw(99)may; Madau & Kuhlen ap/03-proc; Loeb ap/06-ln; Schaerer a0706-ln; Greif et al AIP(08)-a0709; Bromm et al Nat(09)may-a0905; Greif PhD(09)-a0905; Finkelstein ASP-a1004; Johnson ch(12)-a1105 [theory and simulations]; Dunlop ch(12)-a1205 [rev]; news sn(19)aug [massive active galaxies seen in the early universe].
@ Formation, mergers: Silk PT(87)apr; Peebles & Silk Nat(90)jul; Gawiser ASP-ap/05; Conselice ASP-a0706 [massive galaxies]; Gilmore IAU(09)-a0808 [rev]; van den Bergh Nat-a0810; Fontanot et al MNRAS(09)-a0901 [hierarchical models and observation]; De Lucia AIP(09)-a0904; Kraemer et al a0904-rp [active galactic nuclei]; D'Onghia et al Nat(09)jul-a0907 [dwarf spheroidals, resonant stripping]; Benson PRP(10)-a1006 [formation theory]; Oser et al ApJ(10)-a1010 [two phases of formation]; Conselice a1212-conf [rev]; Cimatti et al 19 [and evolution].
@ Spiral galaxies: Athanassoula PRP(84), ap/02-conf [bars]; Efremov et al SPU(89); Friedli ASP-ap/99 [bars]; Silk ApSS(03)ap/02-proc; Combes SA(05)oct; Stringer & Benson ASP-a0712; Silk IAU-a0809; D'Onghia et al ApJ(12)-a1204 [self-perpetuating spiral arms]; Kiselev a1308 [formation]; Sellwood RMP(14); Johnston et al IAU(15)-a1410 [transformation of spirals to lenticulars]; Pour-Imani et al ApJL(16)-a1608 [evidence for density-wave theory].

Observation > s.a. galaxies [rotation and motion, velocities]; milky way galaxy; quasars; types of galaxies.
* Theory and observations: 2015, Observations show that massive galaxies formed much earlier than the current hierarchical merging paradigm and the standard ΛCDM model predict.
* Interactions, mergers: In the 1990s, evidence accumulated that interactions are common and very imporant for galaxy evolution.
@ Formation: news pw(11)apr [clues from metallicity gradients]; Steinhardt et al ApJ(16)-a1506 [the impossibly early galaxy problem].
@ Evidence of past: Ivans et al ap/99-proc [metal-poor, high-velocity stars].

* Mergers: 2012, It seems that major collisions between large galaxies lead to increased mass density at the center of massive elliptical galaxies, while when a small galaxy merges with a larger one, the smaller galaxy is ripped apart and its stars remain near the outskirts of the larger galaxy.
@ General references: Steinhardt & Speagle ApJ(14)-a1409 [common history, and galactic evolution "main sequence"].
@ Later evolution and star formation: Kurbatov AR(07)-a0709 [and turbulent dissipation]; Poggianti et al IAU(13)-a1212 [evolution of galaxy sizes].
@ Chemical evolution: Ziegler ap/04-proc; Matteucci a0704-ln [rev]; Schild a0708 [puzzle of solar abundances at large z]; Prantzos EAS(08)-a0709; McWilliam a1011-proc; Zahid et al ApJL(13)-a1303 [star-forming galaxies out to z = 2.3]; Haywood a1401-conf; Maio & Tescari MNRAS(15)-a1509; Matteucci JPCS(16)-a1602-ln; van Dishoeck IAU(18)-a1710 [astrochemistry, rev].
@ Role of supermassive black holes: Cattaneo et al Nat(09)jul-a0907; Heckman & Best ARAA(14)-a1403 [information from large surveys].
@ Interactions, collisions, mergers: Alladin & Narasimhan PRP(82); Struck PRP(99)ap [intro]; Goto ap/06-proc, Martínez & Muriel MNRAS(06)ap [environmental effects]; Renzini MNRAS(09)-a0906 [approach]; Wetzel & White MNRAS(10)-a0907 [satellite galaxy merging/disruption]; Tonnesen & Cen MNRAS(12)-a1111 [pair interactions versus environment]; news ea(12)oct [results of galaxy mergers]; Lilly et al IAU(13)-a1302 [phenomenological approach].
@ Numerical simulations: Miller AS(92); Davé et al ap/05-proc [formation].
@ Related topics: Berlind et al ApJ(01)ap/00 [biasing and β]; Tolstoy ApSS(03)ap/02-in [dwarfs]; Dobbs & Price MNRAS(08)-a0710 [effect of magnetic field]; Welker et al a1410-IAU [building up spin]; > s.a. galaxy distribution [including bulk flow]; Intergalactic Matter.

main pageabbreviationsjournalscommentsother sitesacknowledgements
send feedback and suggestions to bombelli at – modified 23 jun 2020