withMark Westmoquette (UCL)
Jay Gallagher (Wisconsin-Madison)Bob O’Connell (Virginia)
Richard de Grijs (Sheffield)
Linda J. SmithUniversity College London
MODEST-6 Workshop 29-31 August 2005
HST/STIS SPECTROSCOPY OF A YOUNGSSC IN THE STARBURST CORE OF M82
WFPC2 BVI+H
STScI-PRC2001-08b R. de Grijs
STIS slit =
52”
REGION A: 86 clusters!!
In projection:
Density of 1450 /kpc2
Mean separation = 11 +/- 5 pcMean radius = 5 +/- 2 pc(Melo et al. 2005)
A
180 pc
STIS slit position
52” x 0.1”
0”.1 = 1.8 pc
M82-A1
WFPC2 V-band image
STIS G430L + G750M spectra of M82-A1
• Age = 6.4 +/- 0.4 Myr• E(B-V) = 1.35 +/- 0.15 mag• V = 17.23 +/- 0.1 mag• MV = -14.8 +/- 0.4 mag• Mass = 7-13 x 105 Msun
• Half-light radius = 3.0 +/- 0.5 pc
• Mass density = 6-11 x 103 Msun
pc-3
[NII]+H
[SII]D
ist a
nce a
lon
g s
lit
->
Small HII region around M82-A1
•Half-light radius = 4.5 +/- 0.5 pc•Electron density = 1800 cm-3
•Pressure P/k = 2 x 107 cm-3 K