2/18/2023 0 Comments Massive star![]() ![]() We propose a picture that integrates most of the major features in this part of the sky, excepting the nonthermal filaments. The total luminosity from the massive cluster stars is ~10 7.5 L solar, enough to account for the heating of the nearby molecular cloud, M0.20-0.033. The newly identified stars increase the estimated ionizing flux from this cluster by about an order of magnitude with respect to earlier estimates, to 10 50.9 photons s -1, or roughly what is required to ionize the nearby ``Sickle'' H II region (G0.18-0.04). The implied mass density in stars is greater than or similar to a few thousand M solar pc -3. The total mass in observed stars is ~10 3 M solar, and the implied mass is ~10 4 M solar, assuming a lower mass cutoff of 1 M solar and a Salpeter initial mass function. Given the evolutionary stages of the identified stars, the cluster appears to be about 4+/-1 Myr old, assuming coeval formation. Although the cluster parameters are uncertain because of photometric errors and uncertainties in stellar models, i.e., extrapolating initial masses and estimating ionizing fluxes, we have the following conclusions. One newly identified star is the second luminous blue variable in the cluster, after the ``Pistol star.'' Although we are unable to provide certain spectral classifications for the five enigmatic Quintuplet-proper members, we tentatively propose that they are extremely dusty versions of the WC stars found elsewhere in the cluster and similar to the dozen or so known examples in the Galaxy. We find that the cluster contains a variety of massive stars, including more unambiguously identified Wolf-Rayet stars than any cluster in the Galaxy, and over a dozen stars in earlier stages of evolution, i.e., luminous blue variables (LBVs), Ofpe/WN9, and OB supergiants. We present near-infrared photometry and K-band spectra of newly identified massive stars in the Quintuplet cluster, one of the three massive clusters projected within 50 pc of the Galactic center. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |