FSR 1776: a new globular cluster in the Galactic bulge

TiO bands at λ 620 nm are synthesized. The behaviour of these bands as a function of stellar parameters is studied. Application to composite spectra of one galactic bulge globular cluster and to bulges of elliptical galaxies is also carried out. TiO bands may be useful metallicity indicators.

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Terzan 5: a pristine fragment of the Bulge

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314005602 ◽

2012 ◽

Vol 10 (H16) ◽

pp. 243-244

Author(s):

Francesco R. Ferraro

Keyword(s):

Globular Cluster ◽

Iron Content ◽

Stellar System ◽

Stellar Populations ◽

Galactic Bulge ◽

Chemical Similarity ◽

Different Ages ◽

Supernova Explosions

AbstractWe have discovered that Terzan 5, a stellar system in the Galactic Bulge, harbors two stellar populations with different iron content (Δ[Fe/H] ~ 0.5 dex) and possibly different ages. Moreover, the observed chemical patterns significantly differ from those observed in any known genuine globular cluster. These evidences demonstrate that, similarly to ω Centauri in the Halo, Terzan 5 is not a globular cluster, but a stellar system that was able to retain the gas ejected by violent supernova explosions. Moreover the striking chemical similarity with the Bulge stars suggests that Terzan 5 could be the relic of one of the massive clumps that contributed (through strong dynamical interactions with other pre-formed and internally-evolved sub-structures) to the formation of the Galactic Bulge.

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Star formation in the Galactic bulge: the role of collisions

Proceedings of the International Astronomical Union ◽

10.1017/s1743921308017614 ◽

2007 ◽

Vol 3 (S245) ◽

pp. 189-190

Author(s):

Mark Cropper ◽

Dave Vande Putte

Keyword(s):

Star Formation ◽

Globular Cluster ◽

High Frequency ◽

Galactic Bulge ◽

Galactic Disks ◽

Cluster Cores

AbstractPrompted by the possibility that we have observed star formation triggered by globular cluster and dwarf spheroidal transits through galactic disks, we have examined kinematic evidence as to whether the superstar clusters in the Galactic bulge could have been formed from such transits. From their trajectores, we cannot exclude such a possibility. We note also that the high frequency of these transits may have generated rapid star formation at early times, and that remnant cluster cores may themselves nucleate further star formation.

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