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Roma, 4 Novembre 1868:
the Beginning!
Contents:
 CS as standard candles
CS as tracers of low density halos & tidal tales
 CS as kinematical probes
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Standard Candles
Theory
Evolutionary models of
stellar systems suggest
that <Mbol> of CS does not
depend on the metallicity.
(see e.g. Mouhcine&Lançon, 2003)
Powerful standard candles:
 brighter than Cepheids;
 single epoch of observation;
 reduced absorption (NIR);
 brighter than the TRGB.
Standard Candles
observations
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
Four Band Photometric System
• Palmer & Wing (1982)
• Cook & Aaronson (1989)
• Richer et al. (V,I,CN,TiO)
• B&D (R,I,CN,TiO)
Standard Candles
results from our ongoing survey
When CS are carefully and
homogeneously identified
(FBPS in our survey):
 <MI> independent of [Fe/H]
 <MI> scatter for faint
galaxies
Low-Density Environment Tracers
results from our ongoing survey
The case of NGC 6822
and its extended halo….
… of old and intermediate
age stars.
Low-Density Environment Tracers
results from our ongoing survey
exp. disk:
2.96± 0.14 arcmin
… and the missing
halo of NGC 3109…
minor axis:
4-5 arcmin
Low-Density Environment Tracers
results from our ongoing survey
… the tidal debris
around NGC 205.
About 500 CS identified
(2003, AJ June)
Low-Density Environment Tracers
results from our ongoing survey
… the tidal debris
around NGC 205.
Extratidal stars NW of NGC 205
Kinematical Probes
follow-up of our survey
the stellar rotation
curve and the mass of
Andromeda galaxy
 900 CS identified along
the SW major axis from
17 to 30 (2003 AJ, 125, 1298)
 extention up to 40 kpc
(TNG-QSO, July 03)
Kinematical Probes
follow-up of our survey
the stellar rotation
curve and the mass of
Andromeda galaxy
20 kpc = 80'
30 kpc = 130'
40 kpc = 180'
 900 CS identified along
the SW major axis from
17 to 30 (2003 AJ, 125, 1298)
 extention up to 40 kpc
(TNG-QSO, July 03)
Kinematical Probes
follow-up of our survey
TNG
Gemini N
the stellar rotation
curve and the mass of
Andromeda galaxy
 beyond 30kpc only 2
GCs and none PN
 this will provide the
largest lower estimate of
the mass of M 31
Kinematical Probes
follow-up of our survey
… the monstrous MegaPrime
Kinematical Probes
follow-up of our survey
CS: e.g. Margon et al. 2002
… the monstrous MegaPrime
CS survey in the Local Group
Galaxy
NCS
Status
IC 1613
195
published
Pagasus
40
published
DDO 210
3
published
SagDIrr
16
published
Leo I
13
published
NGC 6822
904
published
M 31 (part.)
945
published
NGC 205
532
published
NGC 3109
326
submitted
NGC 147
288
in preparation
NGC 185
+100
in preparation
IC 10
+1000
just done
WLM
---
data acquired
IC 10