NASA | STScI | HubbleSite | 2015 Sep 03
In a survey of NASA's Hubble Space Telescope images of 2,753 young, blue star clusters in the neighboring Andromeda galaxy (M31), astronomers have found that M31 and our own galaxy have a similar percentage of newborn stars based on mass.[c]Credit: NASA, ESA, J. Dalcanton, B.F. Williams, and L.C. Johnson
(University of Washington), the PHAT team, and R. Gendler[/c][hr][/hr]
By nailing down what percentage of stars have a particular mass within a cluster, or the Initial Mass Function (IMF), scientists can better interpret the light from distant galaxies and understand the formation history of stars in our universe.
The intensive survey, assembled from 414 Hubble mosaic photographs of M31, was a unique collaboration between astronomers and "citizen scientists," volunteers who provided invaluable help in analyzing the mountain of data from Hubble.
"Given the sheer volume of Hubble images, our study of the IMF would not have been possible without the help of citizen scientists," said Daniel Weisz of the University of Washington in Seattle. Weisz is lead author on a paper that appeared in the June 20 issue of The Astrophysical Journal.
Measuring the IMF was the primary driver behind Hubble's ambitious panoramic survey of our neighboring galaxy, called the Panchromatic Hubble Andromeda Treasury (PHAT) program. Nearly 8,000 images of 117 million stars in the galaxy's disk were obtained from viewing Andromeda in near-ultraviolet, visible, and near-infrared wavelengths. ...
The High-Mass Stellar Initial Mass Function in M31 Clusters - Daniel R. Weisz et al
- Astrophysical Journal 806(2):198 (2015 Jun 20) DOI: 10.1088/0004-637X/806/2/198
arXiv.org > astro-ph > arXiv:1502.06621 > 23 Feb 2015