Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.naic.edu/alfa/ealfa/papers/AGES-IAU244.pdf Äàòà èçìåíåíèÿ: Mon Jul 9 21:25:21 2007 Äàòà èíäåêñèðîâàíèÿ: Sat Dec 22 05:46:52 2007 Êîäèðîâêà:

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Outline
· W ha t is A G E S ? · Dark galaxy finding - potential · Dark galaxy finding - reality

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W hat is A GES?
· A de ep H I su rvey of a variety o f en viron m ents. · Total of 200 square degrees in 13 re gio ns.

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W hat is A GES?

I A U S y m p o s i u m 2 4 4 , C a r d i f f , 2 5 t h - 2 9t h o f J u n e , 2 0 0 7


W hat is A GES?
· A de ep H I su rvey of a variety o f en viron m ents. · Total of 200 square degrees in 13 re gio ns. · Noise of 0.45 mJy over V=10 kms-1, FWHM 3.8´.

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W hat is A GES?

I A U S y m p o s i u m 2 4 4 , C a r d i f f , 2 5 t h - 2 9t h o f J u n e , 2 0 0 7


W hat is A GES?
· A de ep H I su rvey of a variety o f en viron m ents. · Total of 200 square degrees in 13 re gio ns. · Noise of 0.45 mJy over V=10 kms-1, FWHM 3.8´. · Can grid with FWHM down to 3.45´.
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W hat is A GES?
Logarithmic Linear Best-fit Gaussian

Residual

Beam Map

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W hat is A GES?

I A U S y m p o s i u m 2 4 4 , C a r d i f f , 2 5 t h - 2 9t h o f J u n e , 2 0 0 7


Dark galaxy finding - potential
· Identification of candidates vital for finding D ark G alaxies. · Median offset between AGES sources and optical counterparts is 18 arcsec.

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Dark G alaxy

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Dark galaxy finding - potential
· Identification of candidates vital for finding D ark G alaxies. · Median offset between AGES sources and optical counterparts is 18 arcsec. · At the median redshift of 12,000 kms-1, corresponds to ~15 kpc (H0 = 70). · Worst case (70 at 18,000 kms-1) ~90 kpc.
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Dark galaxy finding - potential
· D avies et al. (2 00 6) predict ~23 % of AGES sources to be dark galaxies. · This is too high a proportion to loose to misidentification (c.f. 4% for ALFALFA). · AGES can therefore set the best limits on the HI-rich dark galaxy population.

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Dark galaxy finding - reality
· A G E S has covere d 4 regions o r p arts o f regions so far, for a total of 20 sq. deg. · Find around 10 sources/sq. deg. · Therefore the prediction is for around 46 dark galaxies in the survey so far.

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NGC 1156
· Auld 2007 (PhD thesis)
­ 3 sources without apparent optical counterparts on the DSS.

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AGES J0302+2449

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AGES J0302+2449

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NGC 1156
· Auld 2007 (PhD thesis)
­ 3 sources without apparent optical counterparts on the DSS. ­ 1 seen on deeper imaging, ­ 2 awaiting further follow-up.

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AGES J0256+2546

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AGES J0300+2554

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Abell 1 367
· Cortese et al. 2007 (in prep.)
­ See poster in the coffee room. ­ Diffuse hydrogen found in the CGCG 97027 and CGCG 97041 sub-groups in the Abell 1367 cluster.

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CGCG 9 7027

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CGCG 97041

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Abell 1 367
· Cortese et al. 2007 (in prep.)
­ See poster in the coffee room. ­ Diffuse hydrogen found in the CGCG 97027 and CGCG 97041 sub-groups in the Abell 1367 cluster. ­ All of these are likely to be interaction debris. ­ Lost baryons, but not dark galaxies.
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Virgo Cluster
· Taylor P h D f ield
­ See poster in the coffee room. ­ Probable HVCs found in foreground at ~250 kms-1.

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Foreground HVCs?

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Virgo Cluster
· Taylor P h D f ield
­ See poster in the coffee room. ­ Probable HVCs found in foreground at ~250 kms-1. ­ 2 sources without apparent optical counterparts on the SDSS found behind the cluster.

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AGES J1239+1152

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AGES J1243+1148

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NGC 7332
· Minchin et al. 2007 (in prep.)
­ 1 source without an apparent optical counterpart on the DSS found.

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AGES J2237+2253

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AGES J2237+2253

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Dark galaxy finding - reality
· · · · 5 dark galaxy candidates found All have MHI > 108 M. C ou ld b e LS B g ala xies. Others may be misidentified with false optical counterparts. · This is still a long way below theoretical pred iction s.
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Conclusions
· AGES is the best current survey for uncovering a population of HI-rich dark ga la xie s. · So far, number of candidates is ~10% of Davies (2006) prediction. · The survey is ongoing and follow-up w ork is continu ing . · http://www.naic.edu/~ages
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