Presentazione di PowerPoint

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A Carbon Star Survey in the Local Group galaxies
battinel_at_oarph1.rm.astro.it
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Roma, 4 Novembre 1868 the Beginning!
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A Carbon Star Survey in the Local Group galaxies

• CS as standard candles
• CS as tracers of low density halos tidal tales
• CS as kinematical probes

Contents
battinel_at_oarph1.rm.astro.it
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Standard CandlesTheory
Evolutionary models of stellar systems suggest
that ltMbolgt of CS does not depend on the
metallicity. (see e.g. MouhcineLançon, 2003)

• Powerful standard candles
• brighter than Cepheids
• single epoch of observation
• reduced absorption (NIR)
• brighter than the TRGB.

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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

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Four Band Photometric System

• Palmer Wing (1982)
• Cook Aaronson (1989)
• Richer et al. (V,I,CN,TiO)
• BD (R,I,CN,TiO)

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Standard Candlesresults from our ongoing survey
When CS are carefully and homogeneously
identified (FBPS in our survey)

• ltMIgt independent of Fe/H

• ltMIgt scatter for faint galaxies

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Low-Density Environment Tracersresults from our
ongoing survey
The case of NGC 6822 and its extended halo.
of old and intermediate age stars.
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Low-Density Environment Tracersresults from our
ongoing survey
exp. disk 2.96 0.14 arcmin
minor axis 4-5 arcmin
and the missing halo of NGC 3109
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Low-Density Environment Tracersresults from our
ongoing survey
the tidal debris around NGC 205.
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Low-Density Environment Tracersresults from our
ongoing survey
the tidal debris around NGC 205.
Extratidal stars NW of NGC 205
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Kinematical Probesfollow-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)

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Kinematical Probesfollow-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)

20 kpc 80' 30 kpc 130' 40 kpc 180'
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Kinematical Probesfollow-up of our survey
the stellar rotation curve and the mass of
Andromeda galaxy
Gemini N
TNG

• beyond 30kpc only 2 GCs and none PN
• this will provide the largest lower estimate of
  the mass of M 31

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Kinematical Probesfollow-up of our survey
the monstrous MegaPrime
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Kinematical Probesfollow-up of our survey
CS e.g. Margon et al. 2002
the monstrous MegaPrime
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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