Galaxies and the Universe - The Pregalactic Universe

Galaxies and the Universe - The Pregalactic Universe -...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1/15/12 Gala[ieV and Whe UniYeuVe - The PuegalacWic UniYeuVe 1/6 ZZZ.aVWu.Xa.edX/keel/gala[ieV/puimal.hWml TKH PUHJDODFWLF uQLYHUVH TKHUH DUH VHYHUDO UHFRJQL]HG SURFHVVHV IURp WKH HDUO\ XQLYHUVH WKDW OHDYH UHOLF HIIHFWV VHWWLQJ WKH VWDJH IRU JDOD[\ IRUpDWLRQ DQG HYROXWLRQ. wH GHDO KHUH ZLWK WKH ILUVW JHQHUDULRQ RI VWDUV, SULpRUGLDO QXFOHRV\QWKHVLV, WKH HSRFK RI UHFRpELQDWLRQ, DQG WKH WKHUpDO KLVWRU\ RI YDULRXV FRVpLF EDFNJURXQGV. The FiUVW SWaUV sHYHUDO NLQGV RI HYLGHQFH SRLQW WR DQ HDUO\ (SUHJDODFWLF) VRXUFH IRU D VpDOO OHYHO RI HQULFKpHQW LQ KHDY\ HOHpHQWV (HVSHFLDOO\, DW WKLV SRLQW, R[\JHQ). TKHVH LQFOXGH WKH SDWWHUQV RI DEXQGDQFHV LQ H[WUHpH PRSXODWLRQ ii VWDUV LQ WKH MLON\ wD\ DQG WKH o/h UDWLR LQ LQWHUJDODFWLF JDV. TKLV HDUO\ HQULFKpHQW pD\ EH WKH ILUVW HYLGHQFH RI WKH ILUVW JHQHUDWLRQ RI VWDUV, YDULRXVO\ NQRZQ DV PRSXODWLRQ iii, YHU\ pDVVLYH VWDUV (vMoV), RU YHU\ pDVVLYH REmHFWV (vMsV). TKH\ pXVW KDYH EHHQ DEOH WR IRUp LQ D ZD\ GLIIHUHQW IURp ZKDW ZH VHH LQ WRGD\'V uQLYHUVH, ZLWKRXW DQ\ GXVW RU KHDY\ HOHpHQWV WR DVVLVW LQ FRROLQJ WKH JDV GXULQJ FROODSVH. TKLV ZRXOG WLS WKH W\SLFDO pDVVHV WR pXFK JUHDWHU YDOXHV. CRROLQJ DW ]HUR pHWDOOLFLW\ FDQ SURFHHG RQO\ WKURXJK UDGLDWLRQ IURp OLQHV RI pROHFXODU K\GURJHQ (LQFOXGLQJ LWV GHXWHUDWHG IRUp hd), ZKLFK ZLOO IRUp DW YHU\ ORZ FRQFHQWUDWLRQV LQ WKH SUHJDODFWLF uQLYHUVH. iW LV LpSRUWDQW WKDW WKH "QHXWUDO" uQLYHUVH VWLOO KDG DQ LRQL]HG IUDFWLRQ RI RUGHU 10 -4 , VLQFH WKLV IDFLOLWDWHG IRUpDWLRQ RI pROHFXOHV WKURXJK D FKDUJH-H[FKDQJH UHDFWLRQ (UHFHQWO\ GHWDLOHG E\ AEHO HW DO. 1997 nHZAVWURQ 2, 181) VWDUWLQJ ZLWK h 0 + H - --> h - + SKRWRQ TKLV ZHDNO\-ERXQG LRQ WKHQ IRUpV h 2 YLD h - + h 0 --> h 2 + H - VR WKDW LW LV SURSHU WR VSHDN RI WKH IUHH HOHFWURQV DV FDWDO\VWV. TKH h 2 DQG hd pROHFXOHV FDQ FRRO WKURXJK UDGLDWLRQ LQ URWDWLRQDO DQG YLEUDWLRQDO WUDQVLWLRQV O\LQJ LQ WKH QHDU-LQIUDUHG, GRZQ WR WHpSHUDWXUH DURXQG 200 k (ZKHUH WKH FRROLQJ LV VORZHVW). TKLV WHpSHUDWXUH GHILQHV WKH pDVV VFDOHV RQ ZKLFK REmHFWV FDQ FROODSVH LI RQO\ WKLV pROHFXODU FRROLQJ RSHUDWHV; WKH WHpSHUDWXUH LV VHYHUDO WLpHV KLJKHU WKDQ WKH XOWLpDWH OLpLW IURp HtXLOLEULXp ZLWK WKH "pLFURZDYH" EDFNJURXQG WHpSHUDWXUH VHHQ E\ DQ REmHFW DW UHGVKLIW ] , RI 2.7 [ (1+ ] ) k. sHYHUDO UHFHQW QXpHULFDO VWXGLHV (AEHO, BU\DQ, & nRUpDQ 2002 sFLHQFH 295, 93; 2002 ASj 564, 23) KDYH FRQYHUJHG RQ WKH UHVXOWV RI VXFK D FROODSVH. TKH ILUVW VWDUV ZHUH pDVVLYH, KRW, DQG HIILFLHQW DW HQULFKLQJ WKHLU VXUURXQGLQJV LQ SURFHVVHG HOHpHQWV. TKH UHVWULFWHG FRROLQJ SRVVLELOLWLHV pHDQ WKDW RQO\ pDVVHV LQ WKH URXJK UDQJH 80-300 VRODU pDVVHV IRUpHG WKHVH VWDUV, ZLWKRXW IXUWKHU IUDJpHQWDWLRQ DV ZH VHH WRGD\. TKH ODFN RI RSDFLW\ IURp KHDY\ HOHpHQWV pDGH WKHp VXEVWDQWLDOO\ KRWWHU WKDQ HYHQ FRpSDUDEO\ pDVVLYH SUHVHQW-GD\ VWDUV, DQG FRSLRXV HpLWWHUV RI l\pDQ-FRQWLQXXp SKRWRQV. nRW RQO\ GLG WKH\ LRQL]H WKHLU VXUURXQGLQJV, DOEHLW EULHIO\, EXW WKLV UDGLDWLRQ GLVVRFLDWHG WKH h 2 DQG hd WKURXJKRXW WKHLU DQFHVWUDO FORXGV, VR WKDW WKHVH VWDUV IRUpHG RQH WR D "JDOD[\". A ILUVW-JHQHUDWLRQ VWDU RI JLYHQ pDVV ZDV KRWWHU WKDQ DQ\ ODWHU VWDU RI WKH VDpH pDVV. wLWK QR HOHpHQWV WR HQJDJH
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/15/2012 for the course AY 620 taught by Professor Williamkeel during the Fall '09 term at Alabama.

Page1 / 6

Galaxies and the Universe - The Pregalactic Universe -...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online