* Astronomy

Members Login
Post Info TOPIC: NGC 3603


L

Posts: 129605
Date:
RE: NGC 3603
Permalink  
 


Title: Internal dynamics and membership of the NGC 3603 Young Cluster from microarcsecond astrometry
Authors: Boyke Rochau, Wolfgang Brandner, Andrea Stolte, Mario Gennaro, Dimitrios Gouliermis, Nicola Da Rio, Natalia Dzyurkevichá and Thomas Henning

We have analysed two epochs of HST/WFPC2 observations of the young Galactic starburst cluster in NGC 3603 with the aim to study its internal dynamics and stellar population. Relative proper motions measured over 10.15 yrs of more than 800 stars enable us to distinguish cluster members from field stars. The best-fitting isochrone yields Aá V = 4.6-4.7 mag, a distance of 6.6-6.9 kpc, and an age of 1 Myr for NGC 3603 Young Cluster (NYC). We identify pre-main-sequence/main-sequence transition stars located in the short-lived radiative-convective gap, which in the NYC occurs in the mass range 3.5-3.8 M sun. We also identify a sparse population of stars with an age of 4 Myr, which appear to be the lower mass counterparts to previously discovered blue supergiants located in the giant H II region NGC 3603. For the first time, we are able to measure the internal velocity dispersion of a starburst cluster from 234 stars with Iá < 18.5 mag to {\sigma}pm1D = 141 ▒ 27as yr^-1 (4.5 ▒ 0.8 km s^-1 at a distance of 6.75 kpc). As stars with masses between 1.7 and 9 M sun all exhibit the same velocity dispersion, the cluster stars have not yet reached equipartition of kinetic energy (i.e., the cluster is not in virial equilibrium). The results highlight the power of combining high-precision astrometry and photometry, and emphasise the role of NYC as a benchmark object for testing stellar evolution models and dynamical models for young clusters, and as a template for extragalactic starburst clusters.

Read more (68kb, PDF)

__________________


L

Posts: 129605
Date:
Permalink  
 



__________________


L

Posts: 129605
Date:
Permalink  
 



__________________


L

Posts: 129605
Date:
Permalink  
 

ESO is releasing a magnificent VLT image of the giant stellar nursery surrounding NGC 3603, in which stars are continuously being born. Embedded in this scenic nebula is one of the most luminous and most compact clusters of young, massive stars in our Milky Way, which therefore serves as an excellent "loca" analogue of very active star-forming regions in other galaxies. The cluster also hosts the most massive star to be "weighed" so far.
NGC 3603 is a starburst region: a cosmic factory where stars form frantically from the nebula's extended clouds of gas and dust. Located 22 000 light-years away from the Sun, it is the closest region of this kind known in our galaxy, providing astronomers with a local test bed for studying intense star formation processes, very common in other galaxies, but hard to observe in detail because of their great distance from us.

Read more

NGC 3603 is an open cluster of stars situated in the Carina spiral arm of the Milky Way around 20,000 light-years away from our solar system. It was discovered by John Frederick William Herschel in 1834.
Read more

__________________
«First  <  1 2 | Page of 2  sorted by
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard