Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.atnf.csiro.au/whats_on/workshops/mm_science2001/talks/Drinkwater.pdf Дата изменения: Tue Apr 23 11:34:12 2002 Дата индексирования: Wed Dec 26 11:23:50 2007 Кодировка: Поисковые слова: dust

Millimetre observations of red quasars
Michael Drinkwater (Melbourne) in absentia

z Dust in red quasars?
yRachel Webster (Melbourne)

z Variation of the fine structure constant?
yMichael Murphy (UNSW)
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Dust in Red Quasars?
zLarge population of dust-reddened quasars
xB-K colours of radio-selected quasars xWebster et al (1995)

zAssociated mm-wave molecular absorption
xIRAM+SEST, (Mopra) single-dish data -hard xDrinkwater, Combes & Wiklind (1996) -none found

zSynchrotron / power law SED models
xFrancis, Whiting & Webster (2000) xsmall fraction of red quasars due to dust xobserve these with the ATCA
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l

Webster et al (1995, Nature, 375, 469)

lRadio selection

lOptical selection

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Variation of physical constants zThe laboratory: quasar absorption lines
xrotational transition rot: e.g. CO line xhyperfine transition
hyp:

e.g. HI 21cm line

xrot/

hyp



g p 2 = y

xgp=proton g -factor; =fine structure constant xchange in y observed as redshift offset

zObservational limits
x|y/y| < 5x10-6 at z=0.25 and 0.68 xDrinkwater et al (1998)
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l Spectra of the z=0.68 absorption system towards TXS 0218+357

(Murphy et al 2001, MNRAS, 327, 1244)
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X

X

l Comparison of new millimetre/HI constraints (crosses ) on alpha

variation with recent optical constraints (Murphy et al 2001, MNRAS, 327, 1244)

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