17
Roma, 4 Novembre 1868: the Beginning!
Contents:Contents:
[email protected] [email protected]
CS as standard candlesCS as standard candles
CS as tracers of low density halos & tidal talesCS as tracers of low density halos & tidal tales
CS as kinematical probes CS as kinematical probes
Standard CandlesTheory
Evolutionary models of Evolutionary models of stellar systems suggest stellar systems suggest that <Mthat <Mbolbol> of CS does > of CS does not depend on the not depend on the metallicity.metallicity.(see e.g. Mouhcine&Lançon, (see e.g. Mouhcine&Lançon, 2003)2003)
Powerful standard candles:
brighter than Cepheids;
single epoch of observation;
reduced absorption (NIR);
brighter than the TRGB.
Standard Candlesobservations
absolute magnitudes of CN stars span over 8mag !! (Knapp et al. 2000)
cool red-giant size ~10mas with spatial and temporal variation in surface brightness
hard to draw conclusions
• Palmer & Wing (1982)• Cook & Aaronson (1989)• Richer et al. (V,I,CN,TiO)• B&D (R,I,CN,TiO)
Four Band Photometric System
Standard Candlesresults from our ongoing survey
When CS are carefully When CS are carefully and homogeneously and homogeneously identifiedidentified(FBPS in our survey):(FBPS in our survey):
<M<MII> independent of > independent of [Fe/H][Fe/H] <M<MII> scatter for faint > scatter for faint galaxiesgalaxies
Low-Density Environment Tracersresults from our ongoing survey
The case of NGC 6822 The case of NGC 6822 and its extended and its extended halo….halo….
Intermediate-age halo
First d
etection!
… … of old and of old and intermediate ageintermediate age stars. stars.
Low-Density Environment Tracersresults from our ongoing survey
… … and the missing and the missing halo of NGC 3109…halo of NGC 3109…
exp. disk:exp. disk: 2.96± 0.14 arcmin2.96± 0.14 arcmin
minor minor axis:axis: 4-5 arcmin4-5 arcmin
Low-Density Environment Tracersresults from our ongoing survey
… … the tidal debris the tidal debris around NGC 205.around NGC 205.
About 500 CS identified About 500 CS identified (2003, AJ June)(2003, AJ June)
Low-Density Environment Tracersresults from our ongoing survey
… … the tidal debris the tidal debris around NGC 205.around NGC 205.
Extratidal stars NW of NGC 205Extratidal stars NW of NGC 205
Kinematical Probesfollow-up of our survey
the stellar rotation the stellar rotation curve and the mass of curve and the mass of Andromeda galaxyAndromeda galaxy
900 CS identified 900 CS identified along the SW major axis along the SW major axis from 17 to 30 from 17 to 30 (2003 AJ, 125, (2003 AJ, 125, 1298)1298)
extention up to 40 kpc extention up to 40 kpc (TNG-QSO, July 03)(TNG-QSO, July 03)
Kinematical Probesfollow-up of our survey
the stellar rotation the stellar rotation curve and the mass of curve and the mass of Andromeda galaxyAndromeda galaxy
900 CS identified 900 CS identified along the SW major axis along the SW major axis from 17 to 30 from 17 to 30 (2003 AJ, 125, (2003 AJ, 125, 1298)1298)
extention up to 40 kpc extention up to 40 kpc (TNG-QSO, July 03)(TNG-QSO, July 03)20 kpc = 8020 kpc = 80''
30 kpc = 13030 kpc = 130''40 kpc = 18040 kpc = 180''
Kinematical Probesfollow-up of our survey
the stellar rotation the stellar rotation curve and the mass of curve and the mass of Andromeda galaxyAndromeda galaxy
beyond 30kpc only 2 beyond 30kpc only 2 GCs and none PNGCs and none PN this will provide the this will provide the largest lowerlargest lower estimate of estimate of the mass of M 31the mass of M 31
Gemini N Gemini N
TN
G
TN
G
Kinematical Probesfollow-up of our survey
… … the monstrous MegaPrimethe monstrous MegaPrime
Kinematical Probesfollow-up of our survey
… … the monstrous MegaPrimethe monstrous MegaPrime
CS: e.g. Margon et al. 2002CS: e.g. Margon et al. 2002
GalaxyGalaxy NNCSCS StatusStatus
IC 1613IC 1613 195195 publishedpublished
PagasusPagasus 4040 publishedpublished
DDO 210DDO 210 33 publishedpublished
SagDIrrSagDIrr 1616 publishedpublished
Leo ILeo I 1313 publishedpublished
NGC 6822NGC 6822 904904 publishedpublished
M 31 M 31 (part.)(part.) 945945 publishedpublished
NGC 205NGC 205 532532 publishedpublished
NGC 3109NGC 3109 326326 submittedsubmitted
NGC 147NGC 147 288288 in in preparationpreparation
NGC 185NGC 185 +100+100 in in preparationpreparation
IC 10IC 10 +100+10000
just donejust done
WLMWLM ------ data data acquiredacquired
CS survey in the Local CS survey in the Local GroupGroup
IC 10IC 10
