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Ons weet nou dat die meeste sterrestelsels twee of meer sterre het wat om mekaar wentel. Weet ons van sterrestelsels wat 2 of meer supermassiewe swart gate het wat mekaar wentel? Is dit moontlik?
Ja, daar is sterrestelsels met twee supermassiewe swart gate in die middel, sien byvoorbeeld 4C +37.11
Hierdie sterrestelsels word waarskynlik gevorm deur 'n botsing en samesmelting van twee sterrestelsels, en die kern daarvan is nog nie saamgevoeg nie. Bron
'N Vlug van supermassiewe swart gate
Beskou twee supermassiewe swart gate met dieselfde massa wat om hul gemeenskaplike massamiddelpunt wentel. Is dit die geval dat 'n vryval-baan langs die rotasie-as buite die een of ander gebeurtenishorison sal wees op alle swart-gat-skeidingsafstande> 0 (gebaseer op die simmetrie van die situasie)?
Sou u 'n vuurpyl langs 'n pad loodreg op die baanvlak kon navigeer en die lyn tussen die twee swart gate kon sny sonder enige nadelige gevolge, selfs al was die swart gate baie naby aan mekaar?
Aanvullende vraag: Wat is die vorm van elk van die gebeurtenishorisonne voor samesmelting?
Opmerking: ek neem aan dat die getykragte klein sou wees totdat die twee enkelhede uiters naby was. Let ook op dat die punt halfpad tussen die twee BH's die L1 Lagrangian-punt is.
LIGO-geleenthede
Drie bevestigde seine van hierdie rimpelings is sedert 2016 deur die Laser Interferometer Gravitational-Wave Observatory opgespoor
Vanaf vandag het LIGO vier gebeurtenisse bespeur, nie drie nie. Geen van hierdie gebeure was egter van supermassiewe swartgatpare nie, wat per definisie ongelooflik skaars is. Hierdie gebeure behels almal swartmassa-sterre.
Woensdag 20 September 2017 11:58 GMT Rich 11Re: LIGO-gebeure
Presies. Die artikel sê uitdruklik dat LIGO hierdie binêre nie kan opspoor nie.
Interessant . Dit was ooit 'n toneel in sommige wetenskaplikes.
& quot Daar word geglo dat daar enkele reusagtige swart gate in die omliggende materie in die sentrums van die meeste groot sterrestelsels bestaan. Volgens wetenskaplikes, aangesien sterrestelsels bots en saamsmelt, kan die swart gate verstrengel raak om 'n binêre stelsel te word. Namate hulle nader en nader aan mekaar kom, kan hulle nie aan mekaar se swaartekrag ontsnap nie, en uiteindelik in mekaar breek en swaartekraggolwe deur die ruimtetyd kabbel. & Quot
& quotAs hulle nader en nader aan mekaar kom, kan hulle nie aan mekaar se swaartekrag ontsnap nie, en uiteindelik in mekaar breek en swaartekraggolwe deur die ruimtetyd laat kabbel. & # 39
In die klassieke fisika sou die twee massas onbepaald aanhou sirkel, maar Einstein het getoon dat die versnelling van 'n massa daardie ruimtetydgolwe skep wat energie dra. As twee massas dus in 'n wedersydse baan gebind word, word hulle voortdurend beskou & quotaccelerating & quot (dink ek), en die gevolglike golwe bloei van die momentum van die stelsel af en dra dit oor na die heelal as geheel.
Normaalweg is sulke verliese selfs oor miljarde jare min, maar nie wanneer daar baie miljoene sonmassas betrokke is nie. Tog is die golwe te swak om van hierdie afstand af op te spoor, al bly dit nie so nie.
Namate die gate nader kom, wentel dit ook vinniger. Dit, en die strenger baanradius, bevorder groter en beter emissie van swaartekraggolwe, wat die sluitingstempo al hoe meer versnel. Dit is 'n eksponensiële toename, so teen die einde gebeur dinge vinnig. Die frekwensie / krag van die golwe begin vinnig tot die maksimum (a baie), en dan sal selfs 'n baie swak krag soos swaartekrag die heelal laat regop sit en kennis neem.
Gedurende die laaste dae, ure of sekondes voor die samesmelting, word kolossale ruimtetuigings woedend uitgestraal. Dit is miskien die eindstadium-samesmeltingsgolwe wat direk opgespoor word, of miskien die van die werklike samesmelting, nie seker nie.
Moet my nie vra wat by die samesmelting gebeur nie, kan die wiskunde nie hanteer nie. - /
Woensdag 20 September 2017 20:09 GMT Trigonoceps occipitalisVra my nie wat by die samesmelting gebeur nie. & quot
Maklike, Cadbury & # 39s-room-eiers is rommel.
Hierdie pos is deur die outeur daarvan verwyder
Woensdag 20 September 2017 06:17 GMT John Smith 19Ek wil dit noem & quotVic & amp Vince & quot Vega
Omdat hulle albei baie donker is en geneig is tot uiterste geweld.
Re: Ek wil hulle noem & quotVic & amp Vince & quot Vega
Shirley, Donald Jr. en Eric. Omdat hulle baie dig is.
Re: Ek wil dit noem & quotVic & amp; Vince & quot Vega
Kyk vorentoe, sit regop en probeer aandag gee. Ons bespreek die aard van binêre swart gate. U politieke neiging is totaal irrelevant.
Woensdag 20 September 2017 06:56 GMT Vernietig alle monstersNie besonderhede nie. 'N Mens sou hulle kon noem & quotspacetime horisonts & quot
Ons kan hulle noem & quotNull en Void. & Quot
@ Vernietig alle monsters & quotNot besonderhede leemte. 'N Mens sou hulle kon noem & quotspacetime horisonts & quot & quot
Inderdaad, 'n leemte is waar geen saak bestaan nie, maar 'n swart gat is 'n super digte saak. Dit is dus vreemd om die woord in hierdie konteks te gebruik. Daar kan gesê word dat die wette van fisika buite daardie gebeurtenishorison verval, dink ek.
Woensdag 20 September 2017 08:52 GMT Paul KinslerDaar kan gesê word dat die wette van fisika buite daardie gebeurtenishorison verval, dink ek
Die (bekende / aanvaarde) fisika-wette werk net mooi verby die horison, maar ons werk nie naby die sentrale singulariteit nie, want dit is te foutief en ons weet nie hoe om daardie wette so aan te pas of te vervang nie situasies.
Trouens, as u die regte koördinate kies (dws Kruskal & ndashSzekeres), kan u sien dat daar niks baie interessant gebeur met die ruimtetydmaatstaf tydens die gebeurtenishorison nie, selfs al lyk die horison ietwat opmerklik van verder af.
Re: Daar kan gesê word dat die wette van die fisika buite daardie gebeurtenishorison verval, dink ek
Ek sal moet borsel, ek was onder die indruk dat die grootte van 'n swart gat, die Schwarzschild-radius, slegs van buite relevant was (dit wil sê daar is geen normale ruimte binne die gebeurtenishorison), en dat dit eenmaal binne die gebeurtenishorison onvermydelik was om uitgestrek te word na die eiesoortigheid, en dat die tyd effektief stop?
Blak gat digtheid
. 'n swart gat is 'n super digte saak.
Interessant genoeg hoef super-massiewe swart gate nie besonder dig te wees nie. Die swart gat in die middel van die Andromeda-sterrestelsel het byvoorbeeld 'n massa tussen 1.1e8 en 2.3e8 sonmassas. Die gemiddelde digtheid is dus tussen 1,5 g / cm3 (digtheid van droë sand) en 0,3 g / cm ^ 3 (digtheid meel).
Woensdag 20 September 2017 10:59 GMT CuddlesRe: Blak gatdigtheid
& quot. 'n swart gat is 'n super digte saak.
Interessant genoeg hoef super-massiewe swart gate nie besonder dig te wees nie. & Quot
Inderdaad. Die meer akkurate manier om te sit is & quotA swart gat is super digte saak omring deur interessante gravitasie-effekte & quot. Die singulariteit in die middel is uiters dig, maar die swart gat self word gewoonlik beskou as alles tot by die horison van die gebeure, waarvan die meeste redelik leeg is. Dit lyk regtig soos atome - 'n kern is uiters dig, maar atome is meestal leë ruimte en is in die algemeen nie baie dig nie.
Woensdag 20 September 2017 11:28 GMT Paul KinslerRe: 'n Swart gat is uiters digte materie, omring deur interessante gravitasie-effekte
Ek het dit andersom gesê - 'n swart gat is interessante gravitasie-effekte - veral 'n gebeurtenishorison - wat gewoonlik gegenereer word deur 'n groot superdigte massa
Kan daar saak wees waar daar geen tyd is nie?
In werklikheid is swart gate oor die algemeen vakuumoplossings, dus in 'n sekere sin is dit nie 'n uiters digte saak nie.
@Kaltern
Re: @Kaltern
En nog 2. Sien, mense gee om!
(Afgesien van die ellendige git wat my ander pos benoem het. Ek verbeel my dat ek uiteindelik die emosionele trauma sal oorkom.
Woensdag 20 September 2017 07:50 GMT eldakkaWel, die wat ons kan op te spoor, in elk geval.
& quotSkei deur 'n afstand van minder as een ligjaar & quot
U kan 'n ruimtebus daar inpas.
Re: & quotSkei deur 'n afstand van minder as een ligjaar & quot
Dit is hoe Han die Kessel Run gedoen het.
Woensdag 20 September 2017 10:38 GMT TRTStyf swart gat
wat suig alles in? In werklikheid is twee gate naby mekaar. Sien ikoon.
Woensdag 20 September 2017 10:39 GMT Nick RyanStandaard meeteenhede? (@Katyanna Quach)
Jammer Katyanna Quach, maar die massa van die son is nie 'n geldige eenheid op hierdie webwerf nie. Meld u asb aan die Vulture Central Standards Bureau vir, erm, & quottraining & quot.
Re: Standaard-eenhede? (@Katyanna Quach)
Ja, sy bedoel & # 393.745318353333333 * 10 ^ 24 LINQ Hotel Recyclings & # 39.
Hopelik sal dit verwarring onder die kommentaar opklaar.
Ek is nogal hartseer niemand het my gestem vir my slim Edding verwysing nie :(
Ek sal ewe hartseer wees as iemand my wel stem vir my dom StarWars-verwysing: - /
24 ligjare uitmekaar
kwalifiseer steeds as 'n & quotbinary & quot? Sjoe, het dit nie geweet nie. Het gedink dat die weegskaal vir binaries baie kleiner was. Het vandag iets geleer wat ek gedoen het.
Re: 24 ligjare uitmekaar
Ons praat oor basies twee dwergsterrestelsels en massa, so 'n 24ste skeiding is skaars gemaklik.
Re: 24 ligjare uitmekaar
Ek glo dat hulle net in 'n stabiele wentelbaan om 'n onderlinge massamiddelpunt moet wees, dus is afstand net belangrik vir sover dit hul swaartekrag op mekaar beïnvloed. Met voorwerpe so swaartekragtig as swart gate, beteken dit dat 'n binêre stelsel oor 'n werklike enorme afstand kan vorm - wat moontlik 'n stelsel kleiner sterre insluit wat elk wentel.
Re: 24 ligjare uitmekaar
Daardie sterre moet in noue wentelbane wees om die swaartekrag van die binêre stelsel te vermy, wat hulle verbruik of redelik vinnig sal laat verwerp. Maar ek dink dat stywe wentelbane nie soveel langer sou hou nie, wat met hul eie swaartekraggolfverliese en gereelde sleepbote uit die ander gat.
Alles rondom en tussen die gate sal nou heeltemal uitgewis word, behalwe 'n paar sterre in 'n verre baan om albei gate wat geleidelik versteur word totdat hulle uiteindelik in die Grand Blender val en in die ewigheid geslinger word, hetsy na buite of binne.
Dit is heel waarskynlik, maar dit is onmoontlik vir enige GW-ontvanger gebaseer op interferometer om so 'n GW-golf te bespeur uit 'n toekomstige samesmelting van hierdie vermeende swart gate. Dit is selfs onmoontlik as die interferometer duisende kilometers lank is. In die eerste plek, omdat swaartekrag steeds met 'n oneindige spoed beweeg soos voorgestel deur Newton Einstein, kon dit inderdaad nie die spoed verander nie. Laat ek byvoeg, 6 jaar vantevore is minuscule swaartekraggolwe van 'n wye frekwensiegebied (bykans nul tot ongeveer 3 KHz) die eerste keer laat in 2010 in my laboratorium geproduseer en opgespoor. Dit is in 'n Amerikaanse patentaansoek, wat nou 'n Amerikaanse patent 8521029 is, gerapporteer. U kan die patentdetail op die USPTO-webwerf sowel as op Google-patente vind. U kan gravitasiegolwe en my werk op Wikipedia bekyk. Laat ek ook byvoeg, al is ek 'n bietjie geheim, is dit onmoontlik om andersins swartgatfusies te registreer, hoofsaaklik as gevolg van die groot hoeveelheid samesmeltings en mdash, kan ek nie meer oor hierdie onderwerp en mdash praat nie as gevolg van te veel GW-geraas rondom ons (lees in my patent oor hoe hierdie geraas gegenereer word). Laat ek jou sê, LIGO het in die verlede eintlik ook nooit swart samesmeltings bespeur nie. Die minste wat ek kan sê, is dat die samesmeltings wat gerapporteer is, 'n resultaat was van die intense verbeelding van die LIGO-mense, om die minste te sê. Tensy LIGO nie vertroue het in hul sogenaamde GW-golfbevindings van BH-samesmeltings nie, waarom sou hulle hierdie navorsing met opgewondenheid twiet? Laat ons dan nie vergeet dat dit 'n bevinding is deur 'n lae-geloofwaardige Indiese span nie, en Indië het USD300 miljoen belê vir 'n onbruikte LIGO-opstelling om na Indië gestuur te word met 'n nuwe naam INDIGO.
Blexit
Wat gebeur as een swart gat sy soewereiniteit bestry en stem om die binêre stelsel te verlaat?
BASIESE EKSTRA-AKTIESE ASTRONOMIE - Deel 7: Sterrestelsels - Morfologiese diversiteit
Elliptiese sterrestelsels teenwoordig met kenmerkende gradiënte met lae digtheid in die sigbare band, sonder bewyse van 'n kernbult. Hul algemene struktuur word nie deur algehele rotasie bepaal nie. Samestellende sterre volg ewekansige, individuele wentelbane, dikwels teen hoë relatiewe snelhede. Op die oomblik is elliptiese materiale feitlik sonder interstellêre gas en stof, wat 'n minimale tempo van nuwe stervorming tot gevolg het. Gevolglik bestaan hulle hoofsaaklik uit ou, rooi populasie II sterre. Van alle sterrestelselsoorte het elliptiese vorms die grootste verskeidenheid groottes en helderheid. Reuse-elliptiese stowwe, gewoonlik in die sentrums van sterrestelsels, kan diamante van 4 miljoen ligjare bereik (IC 1101), meer as 30 keer groter as die Melkweg, en bevat tientalle biljoene sterre. Aan die ander kant is daar baie talle dwerg-elliptiese stowwe met slegs 10 miljoen sterre wat oor minder as 1000 ligjare strek. Reuse- en normale elliptiese vorme word vermoedelik gevorm deur sterrestelsel-samesmeltings, terwyl dwerg-elliptiese vorms in die getysterte van interaksie sterrestelsels. Reuse-elliptiese vorms is waarskynlik die laaste fase in die morfologiese evolusie van sterrestelsels.
Fig.7-1: Elliptiese sterrestelsels, 'n ewekansige monster.
Lensvormige sterrestelsels het 'n kernbult en prominente, maar meestal kenmerkende skywe sonder bewyse van spiraalarmstrukture. Daar word soms na hulle verwys as armlose spirale. Binne die kern volg sterre ewekansige individuele beweging. Op die skywe word ster kinematika oorheers deur gemiddelde sirkelbewegingwat aandui dat lensvormige sterrestelsels rotasie-gestabiliseer is. Nauwkeurige onderskeid tussen die elliptiese en lensvormige lens hang dikwels af van die spektroskopiese rotasiesnelheid en snelheidsverspreidingsmetings. As dit aan die rand gesien word, kan dit maklik uitgeken word aan die vorm wat soos 'n dubbele konvekse lens lyk. Onafhanklike elliptiese stowwe (S0A) is moeilik om visueel te onderskei van die vroeë elliptiese stowwe. Lensvormige sterrestelsels het ook hoofsaaklik ou, populasie II-sterre, baie lae dosisse van nuwe sterre, en 'n skaarsheid aan interstellêre gas wat hulle al verbruik het, of verloor het deur gravitasie-interaksies met ander sterrestelsels. Anders as die elliptiese middels, bevat dit egter steeds interstellêre stof. As dit skuins gesien word, toon sommige stofstowwe rondom die kern. Afgesperde lensvormers word verder in drie klasse verdeel, S0B1 - S0B3, afhangend van die prominensie van die sentrale balk.
Daar word vermoed dat feitlik alle, indien nie alle elliptiese en lensvormige sterrestelsels 'n sentrale supermassiewe swart gat bevat nie.
Fig. 7-2: Lensvormige sterrestelsels, S0A (beelde 1-3) en S0B (beelde 4-5).
Spiraalstelsels bestaan uit 'n sentrale of kernbult, an ekwatoriale skyf, en 'n byna bolvormige galaktiese stralekrans van sterre en bolvormige trosse. Feitlik almal, indien nie almal nie, het ook 'n sentrale supermassiewe swart gat wat 'n belangrike rol speel in die vorming en evolusie van die sterrestelsel. Opnames toon dat spiraalvormige en onreëlmatige sterrestelsels geneig is om dele van die heelal met 'n laer digtheid te vorm, selde in die sentrums van galaktiese trosse. Spirale vertoon 'n wye verskeidenheid groottes: tussen 16 000 en 325 000 ligjare in deursnee en bevat 1 miljard tot 1 triljoen sterre. Die meerderheid draai sodat die spiraalarms die draai-rigting trek. Die uitsonderings is vermoedelik die resultaat van interaksies en samesmeltings van die sterrestelsels.
In Sa- en Sb-sterrestelsels is die kernbult is 'n betreklik groot, dig gepakte sentrale groep Population II-sterre wat gekenmerk word deur ouderdom, rooi kleur en lae metaalagtigheid. In Sc- en Sd-sterrestelsels word die bult geleidelik verminder deur streke van nuwe stervorming wat die kern omring, wat jong, blou voortbring Bevolking I sterre van hoër metallisiteit. Intussen vind daar in Sm-sterrestelsels nuwe stervorming in die hele sentrale volume plaas, en dit bied glad geen onderskeibare bult nie. Die grootte van die bult hang af van die hoeveelheid materiaal wat beskikbaar is vir nuwe stervorming, en van fisiese en swaartekragversteurings wat nuwe stervorming stimuleer.
Ongeveer 67% van die nabygeleë spiraalvormige sterrestelsels (gesien soos dit in onlangse kosmologiese tydperke verskyn het) het 'n kernkroeg wat subtiel of prominent kan wees. Op 'n afstand van 2,5 miljard ligjare is die fraksie 22%. En teen 8 miljard ligjare is dit net 11%. Daar is voorgestel dat die vorming van kernstawe die gevolg is van gravitasie-interaksies tussen sterrestelsels en samesmeltings, dat die stawe die vlak van "volwassenheid" in spiraalstelsels aandui, en dat die stawe geneig is om nuwe stervorming uit te skakel, of eers ontwikkel nadat die grootste deel van die gas in die sterrestelsel verbruik is ..
In baie sterrestelsels, soos NGC 3992, dui 'n versteurde voorkoms op die kruisings tussen die kernstaaf en die spiraalarms daarop dat die staaf en die spiraalvormige skyf met verskillende hoeksnelhede draai. Volgens 'n onlangse studie deur Hilmi et al. (2020), is die kernstaaf 'n dinamiese struktuur wat oor 'n periode van 60 - 200 miljoen jaar tot 100% in lengte beweeg en in hoeksnelheid in omgekeerde verhouding tot die lengte. As gevolg hiervan verbind en skakel die balk af en toe van die spiraalarmkompleks, wat 'n versteurde koppelvlak of 'n ring skep deur die verskil in hoeksnelhede.
Nuwe modelle dui daarop dat spiraalarms gedeeltelik bestaan uit versamelings sterre en interstellêre materie wat deur swaartekrag gebind is, en fisies saam draai. 'N Ander deel bestaan uit sterre, gas en stof wat in en uit die arms beweeg terwyl hulle om die sterrestelsel wentel, en onvermydelik vertraag in die gebiede met 'n hoër digtheid, in ooreenstemming met die digtheidsgolfmodel.
Migrasie van gaswolke na die swaartekragvelde van die spiraalarms lei tot wolkustorting en die vorming van nuwe, baie warm sterre wat die spiraalarms hul kenmerkende ligblou kleur gee.
Waarnemings van spiraalvormige sterrestelsels in optiese en mikrogolfbane wys dit elke klas verskil merkbaar in die inhoud van interstellêre materie wat beskikbaar is vir nuwe stervorming. In Sc- en Sd-spirale bestaan 15% of meer van die totale massa uit interstellêre gas en stof. Gevolglik manifesteer hierdie klasse 'n hoë mate van nuwe stervorming, lang spiraalarms, klein kernbultjies, flokkulasie (klonterigheid) as gevolg van vinnige vorming van groot OB Verenigings, en blou kleur. Daarteenoor is in Sa-spirale slegs ongeveer 2% van die totale massa in die vorm van gas en stof teenwoordig. Nadat hulle die meeste van hul interstellêre materiaal spandeer of verloor het, vertoon hulle lae dosisse nuwe vorming (steeds baie hoër as die elliptiese stowwe), geel kleur van ouer sterre en groot kernbultjies.
Dit wil voorkom asof spiraalstelsel evolusie verloop in die teenoorgestelde rigting van die klassifikasie volgorde. Sm en Sd is miskien die 'vroeë' tipes, en Sa die 'laat', ou sterrestelsels. Die hipotese word ondersteun deur die styfgewonde spiraalarms in die Sa-klas. Aangesien die spiraalarms die rigting van die rotasie van die sterrestelsel volg, word verwag dat ouer sterrestelsels, wat meer rotasies ondergaan het, strenger wond sou bied.
'N Studie uit 2019 wat deur burgerwetenskaplikes bygestaan is, het 'n groot steekproef van 6 000 sterrestelsels geanaliseer en weerspreek die waarneming van Hubble dat sterrestelsels met groter kernbultjies met meer vasgebinde spiraalarms voorkom. Dit is gevind geen korrelasie tussen bultgrootte en spierarm se digtheid nie, wat die idee ondersteun dat die digtheidsgolfmodel nie die enigste meganisme is wat by evolusie van spiraalarm betrokke is nie.
As die studie bevestig word, sou dit ook daarop dui dat evolusionêre weë van die bult en die spiraalarms vroeg in die lewe van 'n sterrestelsel afwyk.
Fig. 7-3: Morfologiese klassifikasie van die spiraalstelsel van Hubble-Vaucouleurs. Subtipes a, b, c, d, m van links na regs
Die onreëlmatige sterrestelsel kategorie word toegeken aan enige sterrestelsel wat nie in die Hubble-Vaucouleurs-klassifikasieskema pas nie. Onreëlmatighede het 'n chaotiese voorkoms met geen definieerbare vorm of interne struktuur nie. Hulle is gewoonlik kleiner as 30 000 ligjare in deursnee en bevat minder as 10 miljard sonmassa materiaal, wat hulle aansienlik flouer maak as die gemiddelde spirale. Gebrek aan organisasie word gewoonlik toegeskryf aan gravitasie-interaksies of botsings met naburige sterrestelsels, of aan een of ander soort gewelddadige interne aktiwiteit. Hulle kan bestaan uit nuwe sowel as ou sterre, en kan 'n beduidende hoeveelheid massa in die vorm van gas en stof hê. Onreëlmatighede kom dikwels voor as satelliete van groter sterrestelsels. Die bekendste voorbeelde is die Magellaanse wolke wat oorspronklik klein blokkies spirale kon gewees het. Interaksie met die Melkweg het gelei tot 'n sterretjie-aktiwiteit en misvormde interne strukture, wat gelei het tot hul klassifikasie as onreëlmatighede. (Gebaseer op die verspreiding van jong Wolf-Rayet-sterre, lang-tydperk Cepheids en planetêre newels, is Large Magellanic Cloud sedertdien herklassifiseer as SB (s) m - 'n spiraal sonder ringe of kernbult - maar met 'n vertrouensvlak van D, naas die laagste). Ongeveer 25% van alle sterrestelsels word as onreëlmatighede gekategoriseer.
Fig.7-4: Onreëlmatige sterrestelsels
Dwerg sterrestelsels bevat gewoonlik minder as 'n paar miljard sterre. Alhoewel dwerge die algemeenste sterrestelsel in die heelal is, is dit veral moeilik om op groot afstande op te spoor as gevolg van klein grootte en lae helderheid. Hulle kom gewoonlik voor in sterrestelsels, wat wentel en in wisselwerking is met groot sterrestelsels wat lyk asof dit hul vorming en aktiwiteit beïnvloed. Daar is byvoorbeeld bekend dat meer as 20 die Melkweg vergesel. Die een, die Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph), smelt tans saam met die Melkweg en dra sy kern - bolvormige tros M54 - by tot ons stelsel. Omega Centauri, die grootste van bolvormige trosse, is in werklikheid die kern, met 'n sentrale swart gat, van 'n dwergstelsel wat deur die Melkweg al eeue gelede aangelê is. Aangesien daar waargeneem word dat dwerge deelneem aan die evolusie van groot sterrestelsels, is daar baie wetenskaplike belangstelling in hul ontstaan. Hulle word vermoedelik gevorm deur swaartekrag ineenstorting van groot wolke intergalaktiese gas en stof wat veroorsaak word deur eksterne skokgolwe of deur assosiasie met plaaslike konsentrasies van donker materie.
Op grond van hul vorm en samestelling word dwerge in verskillende soorte verdeel:
1) Dwerg elliptiese sterrestelsels (dE) het elliptiese vorm, min of geen gas of stof nie, en toon geen bewyse van nuwe stervorming nie. Dit is algemeen in trosse van groot sterrestelsels, dikwels as satellietgenote. Alhoewel dit op 'n kleiner skaal as normale elliptiese vorms voorkom, het dit verskillende ligverdeling en baie laer metallisiteite wat daarop dui dat dit verskillende entiteite is, met oorspronklike oorsprong in die vroeë Heelal.
2) Sweroidieragtige sterrestelsels (dSph) is klein sterrestelsels met 'n lae helderheid, met min of geen interstellêre materie, geen nuwe stervorming nie, en antieke sterpopulasies wat tot 13 miljard jaar oud is, amper so oud soos die heelal. Met diameters kleiner as 1 600 ligjare en 'n massa van minder as 100 miljoen sonkrag, is dit baie kleiner as dwerg-elliptiese. Daar word voorgestel dat hulle dieselfde klas voorwerpe as bolvormige trosse het, maar die sterk dinamika dui daarop dwerg-sferoïedale word direk geassosieer met hoë konsentrasies donker materie. As gevolg van klein grootte en lae helderheid, is dit slegs in die plaaslike groep waargeneem. Feitlik almal is satelliete van die Melkweg of die Andromedastelsel.
3) Dwergspiraalstelsels (dS) is soortgelyk aan groot spiraalvormige sterrestelsels in terme van morfologiese, optiese en kinematiese eienskappe. Hulle manifesteer kernbultjies, roterende spiraalstrukture, vaste teenwoordigheid van neutrale waterstof en bewyse van nuwe stervorming. Hulle is redelik skaars, en word byna uitsluitlik in die veld buite sterrestelsels aangetref. Daar word geglo dat gravitasie-interaksie met groot sterrestelsels hul interne struktuur onderbreek en uiteindelik in dwerg-elliptiese vorme omskep. Hulle is gewoonlik kleiner as 17 000 ligjare in deursnee en het 'n absolute grootte tussen -16 en -17.
4) Dwerg onreëlmatige sterrestelsels (dIrr of dI) is klein weergawes van die groot onreëlmatige sterrestelsels. Hulle het 'n chaotiese morfologie met geen definieerbare strukture nie, gemengde sterpopulasies met 'n relatiewe lae gemiddelde metallisiteit, aansienlike gas- en stofinhoud, en sterk bewyse van nuwe stervorming. Dit word gereeld aangetref as satelliete van groot sterrestelsels, wat swaartekragvervorming, sterretjie-aktiwiteit en samesmeltings ondervind. Dwergonreëlmatighede word beskou as 'n plaaslike, meer onlangs gevormde weergawe van die mees algemene tipe sterrestelsels in die vroeë heelal.
5) Magellaanse soort dwergstelsels (dSBm) is dwergspiraalstelsels onder swaartekraginvloed deur 'n groot buurman, wat lyk soos die Groot Magellaanse Wolk. Hulle kan bewys lewer van 'n staaf, 'n enkele spiraalarm en sterretjie-aktiwiteit, maar het geen kernbult nie. Hulle ondergaan die proses van omskakeling van dwergspirale in dwergonreëlmatighede.
6) Flou blou sterrestelsels (FBG) is dwerg-onreëlmatige sterrestelsels wat intensiewe sterburst-aktiwiteit ondergaan het toe die lig wat ons tans waarneem, uitstraal. Op optiese foto's lyk dit intens blou en vertoon 'n lae B-V kleurindeks. Spectroskopies toon baie waterstof-alfa-emissielyne wat ooreenstem met die teenwoordigheid van talle jong, warm, blou sterre wat hul buitenste omhulsels en opwindende waterstofwolke met ultravioletstraling afwerp. Hulle is aanvanklik 30-40 jaar gelede in lugopnames geïdentifiseer as dowwe, klein, blou sterrestelsels wat wissel in 'n skynbare bolometriese grootte bo 21, met rooi verskuiwings tussen 0,1 en 2. Meer onlangs het Hubble-diep lugbeelde getoon dat blou dwerge is die algemeenste sterrestelsel in die heelal en word die afgelope paar jaar minder (by laer rooi verskuiwings). Daar word gedink dat FBG's in konvensionele dwergstelsels ontwikkel namate hulle hul gasinhoud verbruik, en die sterburstaktiwiteit geleidelik afneem. Die meganisme wat 'n aanvang van sterretjie-aktiwiteit in veld-FBG's is, is nie bepaal nie, maar kan so eenvoudig wees as gravitasiekrimping van gewone, baroniese saak binne oordensiteite van donker materie en skokgolwe wat voortspruit uit die aanvanklike generasie supernovas.
Fig. 7-5: flou blou sterrestelsels (FBG's), die talrykste sterrestelsel in die heelal. (HST-diepveldbeeld)
7) Blou kompakte dwerg sterrestelsels (BCD) is 'n spesiale soort dwerg-onreëlmatige of elliptiese sterrestelsels wat 'n hoë mate van nuwe stervorming openbaar, wat groot trosse jong, massiewe, baie warm, blou sterre tot gevolg het. Hulle massa is gewoonlik ongeveer 1 miljard sonkrag, met 'n deursnee van minder as 10 000 ligjare. BCD-spektra toon hoë konsentrasies van oer-neutrale en geïoniseerde waterstof en helium, sterre met 'n lae metaalagtigheid (jonger as 10 miljoen jaar), geen stofinhoud nie, en steil rotasiekrommes veral rondom die middel. As gevolg van klein grootte en lae absolute grootte, kan dit nie by hoë rooiverskuiwings waargeneem word nie, maar dit word vermoed dat dit plaaslike weergawes van die FBG's is. Regionale konsentrasies van donker materie alleen is onvoldoende om vinnige rotasie en hoeksnelheidsgradiënte binne BCD's te verklaar. Gevolglik word daar gedink dat hulle gevorm word deur die ontploffing van sterretjie-aktiwiteite as gevolg van botsings en samesmeltings tussen ander dwergstelsels, of deur baie noue ontmoetings met groot bure.
8) Ultra-kompakte dwerg sterrestelsels (UCG, UCD) is een van die bekendste sterrestelsels. Binne diameters wat wissel tussen 40 en 650 ligjare, kan hulle massas tot een miljard son hê. Dit kom voor in die sentrale streke van sterrestelsels (gemiddeld 2,7 per sterrestelsel) in die plaaslike heelal omdat dit te klein en flou is om by rooiverskuiwings bo 0,6 geïdentifiseer te word. Met ou, minder helder sterpopulasies met lae metaalagtigheid, sonder gas-, stof- of nuwe stervorming, is dit groter as die grootste bolvormige trosse van die Melkweg, maar baie kompakter as die kleinste dwergstelsels met soortgelyke helderheid. 'N Aantal hipoteses bestaan oor die ontstaan van UCG's. Die oortuigendste is dat UCG's oorblyfsels is van dwergstelsels waarvan die swaartekragvelde van die omliggende sterrestelselgroep die buitenste lae verwyder.
Hierdie scenario word ondersteun deur Seth et al., (2014), wat kinematiese data van die ultra-kompakte dwergstelsel M60-UCD1 gemodelleer het, en die aanwesigheid van 'n sentrale supermassiewe swart gat (SMBH) van 20 miljoen sonmassas, wat 15 verteenwoordig, onthul. % van die voorwerp se totale massa. M60-UCD1 massa / helderheidsverhouding stem ooreen met ander UCG's, wat impliseer dat daar nog onontdekte SMBH in die res van die bevolking gevind kan word.
33) Buitengewone sterrestelseltipes
Donker sterrestelsels is hipotetiese sterrestelselmodelle wat bestaan uit roterende konsentrasies donker materie wat verband hou met oer-neutrale waterstof- en heliumwolke, wat baie min of geen waarneembare sterre bevat nie. Teoretiese modelle voorspel massa-beramings tussen 1 miljard en 1 triljoen sonkrag. Anders as 'gewone' intergalaktiese gaswolke, bevat donker sterrestelsels donker materie wat 'n hoë massa, strukturele kohesie en spesifieke rotasie-eienskappe aan die baryoniese gaswolk verleen. Soek na donker sterrestelsels behels die vergelyking van optiese opnames met radioteleskoopopnames teen 21 cm neutrale waterstofgolflengtes. 'N Ander benadering is om na laer rooiverskuiwing waterstofabsorpsielyne in die spektra van agtergrondkwasars te soek. Tot dusver bly die bestaan van donker sterrestelsels omstrede. Een lewensvatbare kandidaat is MaagdHI21, 'n uitgebreide wolk neutrale waterstof, van 100 miljard sonmassas, waarvan die interne beweging en sterk swaartekrag-effek in die vorm van 'n getekende spiraalarm op die nabygeleë sterrestelsel NGC 4254 (M99) die teenwoordigheid van donker materie impliseer.
'N Ander kandidaat is Smith's Cloud, in 1963 ontdek deur die astronomiestudent Gail Smith. Die 2 miljoen sonmassawolk van meestal neutrale waterstof, 9 800 ly in maksimum deursnee, ongeveer 40 000 ly van die aarde af, nader die Melkweg teen 73 km / s en sal na verwagting binne 30 miljoen jaar met die Perseus-spiraalarm bots. As dit in die optiese band sigbaar was, sou dit 11 grade op die naghemel onderwerp, ongeveer so breed soos die konstellasie van Orion. Die baan dui daarop dat dit ongeveer 70 miljoen jaar gelede al deur die Melkweg is, maar sonder dat die samehorigheid verlore gaan. Dit dui daarop dat die gewone materie ingebed is in 'n beskermende stralekrans van donker materie, en dat die totale massa daarvan baie hoër is as die beramings gebaseer op baroniese materie.
'Amper donker' sterrestelsels is stelsels met 'n buitengewone hoë neutrale waterstofinhoud (HI) wat in die radioband opgespoor word, en buitengewoon lae helderheid van die oppervlak in die optiese band as gevolg van minimale sterpopulasies. As sodanig het hulle die hoogste massa- tot helderheidsverhoudings van alle sterrestelsels. Die oorsaak van onderdrukte sterre-vormingsyfers bly onbekend. Sommige van hierdie sterrestelsels (bv. AGC 227982 en AGC 26833) is ontdek in 'n vrugtelose soeke na donker sterrestelsels.
Ultra Diffuse Galaxies (UDG) are extremely low luminosity systems devoid of star-forming gas, containing relatively small numbers of ancient population II stars. A study of UDGs in the Coma Cluster found them to have a similar distribution to the ordinary, luminous galaxies. It is presumed they are formed from ordinary galaxies which have lost their gas, dust, and peripheral content in gravitational interactions with larger neighbors. Studies of velocity dispersion of UDG globular clusters indicate that some are embedded in thick halos of dark matter, while others are completely free of dark matter. For example, Coma Cluster UDG Dragonfly 44 was found to have a mass of 1 trillion solar, but only 1% of the luminous star content of the Milky Way. It appears to be composed almost entirely of dark matter. Meanwhile, very low globular cluster velocity dispersion in ultra diffuse galaxies NGC 1052-DF2 and NGC 1052-DF4 indicates that their total masses are consistent with their observed stellar masses alone, with no dark matter contribution. Such galaxies with standard Newtonian orbital mechanics, are important in disproving alternate gravity hypotheses developed to dispense with the concept of dark matter.
Low Surface Brightness Galaxies (LSB) belong to a large and diverse group of systems whose central surface brightness is lower than the background sky-glow. While no convention exists for defining the group, discussions generally involve galaxies fainter than blue apparent magnitude of 23 arcsec^-2. Due to low luminosity and contrast, it is believed the numbers of LSBs in galaxy surveys are significantly underestimated in the local Universe, but especially at higher redshifts. These galaxies are characterized by very abundant gas content, blue color, low star counts, low metallicity, and no known supernova activity. They usually occur isolated in the field, outside of gravitational influence of other galaxies, which might explain very low rates of new star formation. Kinematic studies reveal them to have extremely high ratios of mass / (star + gas) luminosity, suggesting that up to 95% of their mass consists of non-baryonic dark matter. LSBs range in size from dwarfs to Giant low surface brightness galaxies(GLSB) which can span over 160,000 light years in diameter, and compare in mass to the largest spiral galaxies in the Universe. Dwarf LSBs are the most numerous subgroup in the local space, but are as yet not detectable at large distances. Some studies suggest that they may have been present among the primordial galaxies, while others suggest they are a relatively recent feature in the evolution of galaxy structure.
Luminous Infrared Galaxies (LIRG) are galaxies which emit more energy in the infrared band than all other bands combined. Inconspicuous at optical wavelengths, they were first detected in 1983 by the Infrared Astronomical Satellite (IRAS), the first space telescope to perform an all-sky survey at infrared wavelengths. Their numbers were greatly increased in subsequent infrared surveys by the Spitzer Space Telescope and the Herschel Space Observatory. In the optical band, virtually all of these objects were found to be interacting or merging galaxies with central supermassive black holes (SMBH). Their high intrinsic luminosity, above 100 billion solar, is due to aktiewe galaktiese kerne (AGN) and extremely high rates of new star formation, between 100 and nearly 3,000 times the rate observed in quiescent spiral galaxies. Total energy output of these galaxies is comparable to quasars, previously thought to be the most energetic objects in the Universe. In fact, the source of energy in LIRG active galactic nuclei are supermassive black holes, just as in quasars. The reason they are not as prominent in the optical band is that LIRG AGNs are surrounded by dense clouds of gas and dust which absorb intense ultraviolet radiation released by SMBH accretion disks, and re-emit the energy in the form of heat in the infrared band. Depending on luminosity, LIRGs are sorted under different subclasses. ULIRGs are ultraluminous infrared galaxies (> 1 trillion solar), HyLIRGs are hyperluminous LIRGs (> 10 trillion solar), and ELIRGs are extremely luminous LIRGs (>100 trillion solar). The most luminous ELIRG so far discovered is WISE J224607.57�.0, at 350 trillion solar. It is formed by a merger of three galaxies, one containing an AGN with a 10 billion solar mass SMBH. Another one, WISE J101326.25+611220.1, was found to have a star formation rate of 2,810 per year, about 3,000 times higher than in the local quiescent galaxies. There is convincing evidence that LIRG luminosity increases as the distance between interacting galaxies decreases, resulting in exponentially stronger gravitational forces and higher star formation rates. The most energetic systems were found to be in the most advanced stages of merging. Although LIRGs are present in the local Universe, they are increasingly more abundant at higher redshifts. For this reason they are thought to be a crucial intermediate stage in the evolutionary pathway from gas and dust rich spiral galaxies to the giant ellipticals.
Fig. 7-6: HST optical images of luminous infrared galaxies in the sequence of increasing intrinsic IR luminosity
Ultrared Dusty Star-Forming Galaxies (DSFG) are large starburst systems which are immensely luminous in the infrared band, but may be completely obscured at ultraviolet and optical wavelengths that are readily absorbed by the natal clouds of gas and dust. The precise difference between DSFGs and LIRGs remains debatable. Some authors define DSFGs as those galaxies which were originally discovered at infrared wavelengths, even if they were later found to have optical complements. Since the 1980s space-based infrared observatory surveys (IRAS, COBE, Spitzer, Herschel) have demonstrated that the infrared radiation field has the same energy density as starlight emission from all galaxies visible in the ultraviolet and optical bands. Thus, traditional observations in these bands miss approximately half of the total star formation activity in the Universe. Although nearly a million DSFGs have so far been identified, their abundance is insufficient to proclaim them as progenitors of all the local, quiescent galaxies. However, they remain of great interest in the study of mechanisms by which extreme star formation and the assembly of stellar populations in the Universe operate. DSFGs are believed to be a relatively early morphological type which appeared in the young and intermediate Universe. Several studies performed at different wavelengths found their median redshifts to be
3.1. It is likely these values will increase with future advances in optics and photodetectors. The most distant DSFG was observed at redshift 6.02, indicating that multiple stages of nucleosynthesis required for dust formation had already occurred by the time the Universe was only 1 billion years old. DSFGs range from small to the largest and most luminous galaxies known. Their star formation rates reach up to several thousand solar masses per year, which implies a relatively short lifespan before they consume most of their natal gas and dust. A subsample of DSFGs is known to contain dust-shrouded SMBH. Infrared luminosity in that group may be dominated by AGN heating mechanisms rather than starburst activity.
Fig. 7-7: Infrared galaxies in the GOODS-N region devoid of foreground objects, 15x60 arcmin. (Herschel-SPIRE)
Extremely UV-Luminous Galaxies (EUVLG) is a new galaxy type recently identified by Marques-Chaves et al. (2020). The authors discovered the first representative of the group, now named BOSS-EUVLG1, to be a dwarf galaxy of extreme luminosity caused by starburst activity of very hot massive stars. Previously it had been classified as a quasar (SDSS J122040.72+084238.1) presumad to be powered by a central supermassive black hole. The estimated star formation rate is 1,000 solar masses/yr, about 1,000 times higher than in the Milky Way, although the galaxy is 30 times smaller. EUVLGs have similar energy generation mechanisms and interstellar medium properties to the Faint Blue Galaxies, however their energy output is markedly higher, and equivalent to quasars. Based on its apparent magnitude of 20.98 and a redshift of 2.469, the galaxy is about 500 times brighter than the Milky Way in the visible band. The authors of the study estimate its absolute magnitude in the ultraviolet band at -24.40, which is 83 times brighter in the UV band than the giant Andromeda Galaxy. Spectroscopic studies of BOSS-EUVLG1 reveal it is composed of young stars of extremely low metallicity born from primordial gas in a very early phase of starburst activity. The rate of star formation is comparable only to the brightest Luminous Infrared Galaxies, but the absence of metals and dust in the interstellar medium allows the ultraviolet and visible radiation to reach us without significant attenuation. The authors believe this galaxy will enter a dusty phase after a number of supernova generations, within only a few hundred million years. At that time its ultravioled and visible light will become absorbed and obscured, and the galaxy will evolve into a luminous infrared type (DSFG or LIRG).
Fig 7-8: Extremely UV-Luminous Galaxy BOSS-EUVLG1, previously classified as a quasar.
Tadpole galaxies are a rare galaxy type characterized by bright, compact heads and long tails composed of stars and gas. While only 0.2% of the local galaxies are tadpoles, they are much more common in the early Universe, comprising about 10% of the galaxies in the HST Deep Field image. When discovered in the 1990s, it was presumed they represent galaxy mergers. More recent work by Elmegreen et al. (2016) suggests that they form when a dwarf galaxy passes through a filament of primordial gas composed primarily of hydrogen and some helium. Rapid accretion and perturbation of gas in the leading edge of the galaxy head trigger rapid formation of massive, hot, O-type stars of very low metallicity. As these stars go through very brief lifetimes, their supernovas enrich the interstellar medium with heavier elements, so that the stars forming further down the tail have progressively higher metallicities.
Fig. 7-9: Tadpole galaxies: A) in the HST Deep Field image, and B) in the local Universe (LEDA 36252 / HST)
Tadpole galaxies illustrate that, In addition to galaxy mergers, another common mechanism of small galaxy growth is primordial gas accretion resulting from kinematic motion through a primordial gas filament.
Tadpole galaxies should not be confused with the Tadpole Galaxy, UGC 10214, which is a spiral galaxy with a long tidal trail of stars and gas drawn out during a merger about 100 million years ago.
Protogalaxies , of primeval galaxies, is a general term for several types (FBG, UCD, UCG, EUVLG) of high redshift progenitors of local, evolved galaxies in the earliest stages of development. By strict definition, they are regarded to be systems of first generation stars forming by gravitational collapse of dense primordial hydrogen and helium clouds, contained within dark matter halos. Since they have a large fraction of massive and very hot spectral type O and B stars, they radiate most of their energy at ionizing ultraviolet wavelengths around 1,000 A, and 10% of the total energy in the lines of the Lyman series of neutral hydrogen. The term Lyman alpha emitter (LAE) was added to these objects when it was understood that it is possible to search for them in the far infrared band with narrow-band filters at the expected redshifted golflengtes. Rauch et al. (2007), Zheng et al. (2017) and Hashimoto et al. (2018) reported dozens of protogalaxies at redshifts above 6, forming during the first billion years after the Big Bang. They are characterized by small size, poorly organized structure, high rates of new star formation, between 250 and several thousand per year, low metallicity, low luminous mass of only several billion stars, but disproportionally high luminosity due to a relatively large population of energetic O and B stars. In theory, they should also have high rates of supernova events.
At the time of writing, the most ancient galaxy known is GN-z11 with a redshift of 11.1. Its light travel time is 13.4 billion years, and cosmological time (since the Big Bang) around 400 million years. HST and Spitzer imaging reveals that GN-z11 is 25 times smaller than the Milky Way, and has only several billion stars with new star formation rate of 20-40 per year.
A less constrained definition of protogalaxies includes all morphologies which are found in the very early Universe, from gravitationally bound concentrations of dark matter to immediate progenitors of evolved galaxies. This definition would combine into one broad class all unevolved galaxy types listed in this section.
While most protogalaxies are much smaller than the Milky Way, several have been discovered which are colossal in size. Martin et al. (2015) reported a protogalaxy about 400,000 light years in diameter at redshift 2.27, corresponding to light travel time distance of 10.8 billion light years. It is in gravitational interaction with quasar UM 287 (PHL 868) which triggered starburst activity in a cosmic web filament.
Marrone et al. (2017) discovered a pair of giant protogalaxies, SPT0311-58, with redshift
7, forming in the Universe only 780 million years after the Big Bang. Starburst activity in both companions, less than 25,000 ly apart, appears to be caused by their gravitational interaction. The larger member contains 270 billion solar masses of stars and gas, and 3 billion solar masses of dust, indicating multiple prior generations of stellar nucleosynthesis. Its star formation rate (SFR) is 2,900 solar masses per year. The smaller member is about 8 times less massive, with SFR of 540. The pair is encompassed by a dark matter halo with a mass of several trillion solar, as massive as theoretically permissible at that cosmological epoch.
Working with the integral field spectrograph at the ESO’s VLT telescope, Borisova et al. (2016) documented a large nebulous halo displaying starburst activity around each one of the 19 quasars studied at redshifts between 3 and 4. In some cases, these quasar halos extended more than a million light years from the central SMBH – about 20 times the radius of the Milky Way.
Fig. 7-10: Nebulous halos around every quasar studied which formed in the early Universe
The starburst activity model was confirmed by Kurk et al. who studied five quasars with redshifts around 6, and masses ranging between 0.3 and 5.2 billion Suns. Using the infrared spectrograph at the VLT, they measured halo metallicities consistent with multiple generations of stellar nucleosynthesis. They conclude that starburst activity and stellar nucleosynthesis around primordial supermassive black holes commenced very early in the history of the Universe. It is not yet clear which type of stellar systems evolve from these objects.
While it is modelled that protogalaxies grow by gradual merger of small precursors, and by the accretion of primordial gas, there is convincing evidence that immensely large systems were also forming in the very early Universe under the influence of strong gravitational fields around primordial SMBHs and within overdensities of dark matter.
Although there exist many reasonable hypotheses regarding the genesis of individual classes of galaxies, there is no general theory of galaxy formation and evolution which explains the observed variety of structure and composition. The wide diversity of galactic morphology suggests that the evolution of galaxy-type objects does not follow a single path, but consists of a series of parallel and intersecting lineages.
NASA Finds Supermassive Black Hole Birthing Stars at "Furious Rate"
It already gets all the matters done energy it can eat, what else is there to give it?
He's already getting a gold star every day.
Yeah more than one a day. thats insane in terms of the timescale the universe normally operates at
It is estimated there are more stars in the observable universe than the number of seconds since the big bang. by a factor of 10.
The universe is one big massive mind boggling thing. Or it's all an illusion.
Employee of the month for sucking so hard sheesh.
I call dibs on all starts that are made and any resources they generate in or around the systems going forward.
Can I do that? Yɺll won't need these starts will you?
Seems like everyday now something more and more crazier is being discovered about this universe.
It’s truly awesome and about time we started looking up as well as within.
If we all put our minds together, we can figure out the meaning of this life and it’s universe eventually.
I guess that's good, it means we (humanity) are still growing up, despite whatever messes we make. Maybe someday we will have developed enough to make sense of all the apparent craziness, both in the heavens and here on Earth.
Well if observing the universe is what causes it to decide it's position. maybe we should mind our own business. lol
I was taught nothing could escape a black hole, not even light, and today I learn they shoot out energy jets that can form stars. Fassinerend.
The energy jets dont come from inside the event horizon. In there space is so bent that going in any direction will bring you to the singularity.
Yeah, recent science has discovered that many black holes have an accretion disc. This is a ring of matter that is spinning around the black hole super fast. Some of it does fall into the black hole, but there is also matter flung out the other way. This is probably what is shooting out and birthing stars.
On a more theoretical note, there is also Hawking radiation that quantum physics predicts comes from black holes and will eventually cause a black hole to evaporate. It’s really technical stuff and hard to wrap a head around.
Black holes allow for a stable orbit close to the event horizon, which has a very high temperature and can create strong magnetic fields. This in turn, allows for those jets. The jets come from outside the event horizon, not inside
The idea that the black hole is "birthing" stars is not accurate. This is a story of empirical confirmation for phenomena which have been anticipated or partially inferred for a long time. NASA Finds Supermassive Black Hole Triggering Stars Formation at "Furious Rate," with "Triggered" in place of "Birthing" would have been a better term, as in this from wiki:
In triggered star formation, one of several events might occur to compress a molecular cloud and initiate its gravitational collapse. Molecular clouds may collide with each other, or a nearby supernova explosion can be a trigger, sending shocked matter into the cloud at very high speeds.[4] (The resulting new stars may themselves soon produce supernovae, producing self-propagating star formation.) Alternatively, galactic collisions can trigger massive starbursts of star formation as the gas clouds in each galaxy are compressed and agitated by tidal forces.[19] The latter mechanism may be responsible for the formation of globular clusters.[20]
A supermassive black hole at the core of a galaxy may serve to regulate the rate of star formation in a galactic nucleus. A black hole that is accreting infalling matter can become active, emitting a strong wind through a collimated relativistic jet. This can limit further star formation. Massive black holes ejecting radio-frequency-emitting particles at near-light speed can also block the formation of new stars in aging galaxies.[21] However, the radio emissions around the jets may also trigger star formation. Likewise, a weaker jet may trigger star formation when it collides with a cloud.[22]
2 antwoorde 2
They are just saying that in our universe of 3 spatial dimensions the event horizon is a 2-sphere.
Ignoring time, our universe is a 3 dimensional manifold because it takes 3 numbers to specify a point within it. Likewise, an event horison is a 2 dimensional manifold because it takes 2 numbers to specify a point within it.
Judging by the comments there is some confusion with the fact that by the phrase "2D surface" we often mean a plane. A plane is a flat 2D surface and we can have curved 2D surfaces as well, and the event horizon is an example of a curved 2D surface. It also has a global topology that differs from the plane.
If you zoom in to a point on a sphere then it does indeed look like a plane. After all, I'm typing this while sitting on a 2D surface (the surface of the Earth) and from here my lawn looks pretty flat. Actually this is an important principle in GR generally. No matter what the spacetime, locally it always looks flat.
I'm not sure why they suggest that it would take a 4d universe to create our universe that would exist inside of a 3d black hole. The reality is that even though our black hole's event horizon is 2d (x and y coordinates) the black hole itself would indeed be 3d as objects would fall toward the center (z coordinate). [think basketball sphere as something was placed inside the air hole] If our universe was indeed inside of a black hole you could simply look at 
this image of the expanding universe and instead invision us falling or being drawn inward toward infinity on the z coordinate which represents the passing of time and x and y representing the current location within space time. As Eistien states gravity is formed by the mass of an object which then warps space/time resulting in acceleration. If the bottom on this picture was a supermassive object infinitely falling toward a bottomless z coordinate in space and we are simply matter falling toward it along that z coordinate then things start to make a little more sense. Scientists seem to make the same mistakes over and over based on observation. We are at the center of the solar system/galaxy/universe. Its expanding, we are shrinking, etc. Dark matter, Dark energy, etc. I don't know how many times we will all go back to Einstien and realize everything is relative. It's really what made that man great. Realitive to us the universe appears to be expanding as we fall faster and faster relative to each other but observe red-shifts in light while not really understanding why our super nova surface area light test show constant luminocity between galaxies. While i could be wrong and we "may not be in a black hole". I do believe we fall vicitim to looking at things from the wrong perspective more often than not.
One could look at the picture generated from the radio telescopes looking to the center of the galaxy to see the very familar shape we see all throughout nature. We now understand that all galaxies are orbiting black holes and we will soon understand that the event horizon of a black hole is no more than space/time warped into a spiral due to massive amounts of pressure placed on the fabrik by an explosion beyond our minds comprehension. Let look at a few things here.
1) birth of black holes usually being with a big bang. 2) We are pretty sure the universe started with a big bang. 3) We've done calculations stating the expansion of the universe was faster than light 4) The initial growth of a black hole exceeds the speed of light. 5) The universe expands rapidly at first and slows over time. 6) Black holes expand rapidly at first and slow over time. 7) The universe has background radation that we cannot see beyond no matter the vantage point taken within the universe either we've reached the end or we've somehow exceeded the speed of light relative to everyting else. 8) Black holes have a event horizon which you can't see beyond because relative to us the gravitational force is greater than the speed of light.
There is a posilbity based on the physics and math. we could be beyond an event horizon falling into a black hole while still observing light from objects outside of the horizon falling at a much slower rate and may be mistaking that for expansion.
String theory assumes that lorentz covariance is a perfect symmetry of our world. If that is true, it means a single photon is allowed to have an arbitrary energy, even greater than Planck length.
You need at least two photons that are not parallel to have a rest frame where something like a Planckian black hole might be generated that will absorb them. But single-photon states cannot be bounded in energy like this in a pure vacuum.
If the vacuum is not pure, presumably the ultra-planckian photon will react with background photons creating black holes in the rest frame and being absorbed by it.
It's theorized that the Planck length is the smallest meaningful unit of distance. A wave with that wavelength would have a frequency of $approx 6.2cdot 10^<34>, ext
The highest measured frequencies of EM waves are Gamma-rays and are typically produced from the decay of atomic nuclei. The most powerful sources of gamma-rays (and usually the sources with the shortest wavelength) are caused by astronomical events. Recently there was a very strong gamma-ray burst from Cygnus-A, . It is estimated that the gamma ray burst was the result of the black hole gobbling up something with three times the mass of the Earth. There is no theoretical upper limit for the frequency of gamma-rays. To make one bigger than what we've seen so far will require starting with a super-massive black hole and something much larger than the Earth. Not quite reproducible in the laboratory. At what frequency does the wavelength = the height of the wave amplitude ? At 7.7646 x 10 20 Hz. The associated wavelength and amplitude is 3.861 x 10 −13 m. The electron Compton wavelength is 2.426 × 10 −12 m, which is 2π times this amplitude. The wave height = the physical space the waveheight occupy in space, similar to the wavelength. My assumption is that the wave height of the basic electromagnetic wave is fixed. Reg. Take a look at some pictures of the electromagnetic spectrum, note that the amplitude is the same regardless of frequency, and note that the dimensionality of action h can be expressed as momentum x distance. Also note that the reduced Planck's constant ħ is h divided by 2π. It's important to note that an electromagnetic wave is an electromagnetic wave. Some people will tell you it's an electric wave and a magnetic wave which generate one another, and therefore no medium is required. That's not true. Check out the Wikipedia electromagnetic wave article and note this: "Also, E and B far-fields in free space, which as wave solutions depend primarily on these two Maxwell equations, are in-phase with each other. This is guaranteed since the generic wave solution is first order in both space and time, and the curl operator on one side of these equations results in first-order spatial derivatives of the wave solution, while the time-derivative on the other side of the equations, which gives the other field". What people call the electric wave is actually the spatial derivative of the electromagnetic wave, while the magnetic wave is actually the time derivative. They are merely two aspects of the same wave, not two different waves. And as Maxwell said, "light consists of transverse undulations in the same medium that is the cause of electric and magnetic phenomena". When an ocean wave travels through the sea, the sea waves. When a seismic wave travels through the ground, the ground waves. When a gravitational wave travels through space, space waves. See LIGO: "Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity. Einstein's mathematics showed that massive accelerating objects (such as neutron stars or black holes orbiting each other) would disrupt space-time in such a way that 'waves' of distorted space would radiate from the source (like the movement of waves away from a stone thrown into a pond)". The same is true for an electromagnetic wave. When an electromagnetic wave travels through space, space waves. This computer-simulated image shows a supermassive black hole at the core of a galaxy. The cosmic monster's powerful gravity distorts space around it like the mirror in a fun house, smearing the light from nearby stars. We're sorry. This audio clip is no longer available. Scientists have discovered a supermassive black hole that may be the biggest ever spotted — and its location in a ho-hum group of galaxies suggests that cosmic monsters like this one might be more common than astronomers previously thought. The newly discovered black hole is about 17 billion times more massive than our sun. Another black hole is currently listed in the Guinness World Records as the heaviest, because it may be as much as 21 billion solar masses. But the measurement of that black hole was not very precise and it might actually be less massive than the new one, which is described in this week's issue of the journal Nature. "It has highest confidence of anything I've seen of being the largest black hole," says Karl Gebhardt, an astrophysicist at the University of Texas, Austin and expert on black holes. He was not involved in the study. Astronomers know only of a few black holes that have reached this mind-boggling size. Garden-variety black holes that form at the end of a star's life are much, much smaller. The recent observation of gravitational waves, for example, detected ripples from the merger of two black holes that were each roughly 30 times the mass of the sun. And then there are the so-called supermassive black holes that can be found at the center of galaxies, like the one in our own Milky Way. "I hate to call that one puny, but it has only 4 million solar masses, and we found one that is 17 billion solar masses," says Chung-Pei Ma, an astronomer at the University of California, Berkeley who led the research in the Aard study. What strikes her is that this beast lives in what she called "a cosmic backwater," an average-looking group of galaxies. The only other known black holes that are about this size were found in dense clusters of very large galaxies. "It's sort of like, you would expect to find skyscrapers at the center of Manhattan, but this one is more like finding a very, very tall building somewhere in a small town in the U.S. where you would not expect to see something so big," Ma says. "It gives the possibility that these monster black holes are much more common than previously thought." What's more, the center of this black hole's galaxy is strangely empty, says team member Jens Thomas, a research scientist at the Max Planck Institute for Extraterrestrial Physics in Garching, Germany. Thomas says it looks like an astonishing number of stars were ejected as two galaxies merged and their central black holes came together. "Because the black hole is so large, and the progenitor black holes also were so large, the amount of stars that have been ejected from the center is as much as the Milky Way disc," Thomas says. "And I think this is pretty fascinating." That scoured core of the galaxy also struck Gebhardt. "It's kind of like it's evacuating the center part of the galaxy," he says. "This is probably the most extreme example of that configuration." And astronomers like to study the most extreme examples, Gebhardt notes, because those are the best tests of whether their theories actually can explain how to make a galaxy. "And that's how you understand effectively where we come from — where the sun comes from, where the Earth comes from," Gebhardt points out. "What we're beginning to piece together is a model of the merger history of black holes throughout the universe." Copyright 2016 NPR. To see more, visit http://www.npr.org/. San Diego news when you want it, where you want it. Get local stories on politics, education, health, environment, the border and more. New episodes are ready weekday mornings. Hosted by Anica Colbert and produced by KPBS, San Diego and the Imperial County's NPR and PBS station. 
Supermassive Black Holes May Be More Common Than Anyone Imagined
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