Globular clusters in the galactic plane Václav Glos Star clusters
Main properities of globular clusters -Age from half to nearly one Hubble time -Tight gravitational bound of members -Rare or none star formation -Low metalicity -Density profile fitable with Kings function Credit: Marco Burali, Tiziano Capecchi, Marco Mancini
Positions of globular clusters in MW
Orbits of globular clusters in MW Credit: Pearson Education
Absorption in visual light Credit: Serge BrunierSerge Brunier
Infrared solution
Milky Way in infrared Credit: 2MASS
Finding globular clusters through disc Credit: VSA -Many field stars -Non-homogenic reddening possibility Difficulties:
Overdensity in star field Credit: C. Moni Bidin et al.
Cluster members decontamination Credit: C. Moni Bidin et al.
Determining cluster parameters Credit: C. Moni Bidin et al. Color Magnitude Diagram - α-enhancement - metalicity - distance modulus - reddening - age Red Giants spectra - α-enhancement - metalicity
Globular clusters in the galactic plane -Most in galactic bulge -Confirmed GCs in trasition region between bulge and disc (for example GLIMPSE- C02 3,7 kpc from galactic center) -One possible GC with distance from galaxy center 5 kpc VVV CL003 Harris W. (2003)
GLIMPSE-C kpc from galactic center -Metal rich [Fe/H] = -0.33±0.14 in the scale of Zinn -Compact – core radius 0.9 pc Credit R. Kurtev et al.
VVV CL kpc from galactic center -Metal rich [Fe/H] = −0.1 ± 0.2 possible open cluster? -Deeper photometry needed Credit: C. Moni Bidin et al.
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